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Ibrahim, Abdullah D., Hussein M. A. Hussein, Ibrahim Ahmed, Emad Abouel Nasr, Ali Kamrani, and Sabreen A. Abdelwahab. "Computer-Aided Design of Traditional Jigs and Fixtures." Applied Sciences 12, no. 1 (December 21, 2021): 3. http://dx.doi.org/10.3390/app12010003.
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Conventional design of jigs and fixtures has become unsuitable given the requirements of modern technology and complexity and diversity in the production with the rapid update of products. Computer-aided design (CAD) of jigs and fixtures is an effective solution in this direction. The current paper focuses on a computer-aided design of the traditional jigs and fixtures and developed a system containing tailor-made software, created using the Visual Basic programming language and installed on it the viewer screen to show the part. The developed system has been built by connecting Visual Basic programming language to the SolidWorks software on which the part is drawn and saved as STEP AP-203 file format, and the system reads and extracts the data from the STEP AP-203 file. Heuristic rules of feature recognition are pre-prepared for checking the extracted geometric data and deciding which data shape will represent the machining feature; then, the system provides the optimum design of the traditional jigs and fixtures for a group of hollow cylindrical parts that contain a group of cross-holes on the cylinder body, whether perpendicular or offset from the cylinder’s axis, (inclined or inclined offset, or blind or through, by applying pre-prepared heuristic rules for the design of traditional jigs and fixtures.
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Hussein, H., A. Mahrous, A. Barakat, and O. Dawood. "COMPUTER AIDED TRADITION JIGS AND FIXTURES DESIGN." International Conference on Applied Mechanics and Mechanical Engineering 17, no. 17 (April 1, 2016): 1–11. http://dx.doi.org/10.21608/amme.2016.35218.
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Nee, A. Y. C., N. Bhattacharyya, and A. N. Poo. "Applying AI in jigs and fixtures design." Robotics and Computer-Integrated Manufacturing 3, no. 2 (January 1987): 195–200. http://dx.doi.org/10.1016/0736-5845(87)90102-5.
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Miller, A. S., and R. G. Hannam. "Computer Aided Design Using a Knowledge Base Approach and its Application to the Design of Jigs and Fixtures." Proceedings of the Institution of Mechanical Engineers, Part B: Management and engineering manufacture 199, no. 4 (November 1985): 227–34. http://dx.doi.org/10.1243/pime_proc_1985_199_073_02.
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Lin, Tsong Der, and Alan C. Lin. "The Use of Supports to Fast Fabrication of Plastic Parts." Advanced Materials Research 939 (May 2014): 222–29. http://dx.doi.org/10.4028/www.scientific.net/amr.939.222.
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This paper provides a design technique of support for being applied in fast fabrication on plastic prototype, the plastic part developed through the computer aided design (CAD) can be rapidly fabricated by a CNC machining center without needs of any specific jigs or fixtures, the function provided is similar to a rapid prototyping (RP) machine used for fabricating the sampling part. By the testing result, the provided design technique of support can not only be applied in the part required for a dual-surface (or multiple-surface) processing, but also applicable for fabricating the part having thin housing. As such, this paper provides another economical and efficient option besides the RP.
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Neitmann, Maximilian, Tom Rothe, Erik Kappel, and Christian Hühne. "Assembly of Compliant Structures with Autonomous Industrial Mobile Manipulators (AIMM) Using an End Effector with Active Deformation Compensation for the Assembly of Flaps." Machines 10, no. 5 (April 21, 2022): 291. http://dx.doi.org/10.3390/machines10050291.
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Composite structures in aeroplanes are often thin-walled and lightweight, resulting in significant compliance, which presents a handling and assembly challenge due to the associated part deformations. In order to counteract these deformations, the parts are held in their specified geometry using stiff and correspondingly heavy fixtures or jigs. Mobile industrial robots are very versatile and widely used in industrial volume production, but they are limited in their payload capacity. High-rate production of large aerospace modules requires highly automated flexible assembly processes. The approach presented in this paper is to combine mobile units with lightweight assembly jigs that have the capability of deformation compensation. The subject of the study is a high-rate assembly process for flap modules using an Autonomous Industrial Mobile Manipulator (AIMM) and a lightweight end effector. The end effector has a shape compensation function, implemented by an integrated Stewart platform, which enables the compensation of manufacturing tolerances as well as gravity effects. The compensation function is used in a closed loop and counteracts shape deviations by appropriate fixture shape adjustments. The paper reports on the conceptual design of the assembly scenario, the design of the end effector, its realization and the successful experimental demonstration at 1:1 scale.
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King, D. A., and A. de Sam Lazaro. "Process and Tolerance Considerations in the Automated Design of Fixtures." Journal of Mechanical Design 116, no. 2 (June 1, 1994): 480–86. http://dx.doi.org/10.1115/1.2919404.
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The long lead time for jig and fixture design is a serious bottleneck in modern manufacturing. Efforts to automate the design process using intelligent CAD systems have not been taken beyond the prototype stage mainly because of several impediments. These include the requirement of complex data structures to represent the workpiece and its attributes. Two deficiencies in existing systems for fixture design are addressed. These are (a) design for a sequence of operations and (b) design with tolerance considerations. Tolerance and process specifications are obtained from the user during an interactive session. A knowledge-based design system, REFIX, then designs a fixture for the workpiece. The fixture is optimized for a particular datum specification and sequence of operations. It is then analyzed and presented via the CAD system. REFIX is automated to minimize user-induced errors.
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Tjiptady, Bella Cornelia, Rifki Zainur Rahman, Ratna Fajarwati Meditama, and Gede Widayana. "Jig and Fixture Redesign for Making Reamer on Head Cylinder." Jurnal Pendidikan Teknik Mesin Undiksha 9, no. 1 (March 25, 2021): 32–41. http://dx.doi.org/10.23887/jptm.v9i1.32597.
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Proses produksi telah banyak berevolusi dengan diperkenalkannya konsep manufaktur inovatif yang handal. Salah satu komponen mesin yang banyak diproduksi adalah cylinder head. Cylinder head harus tahan terhadap temperatur dan tekanan yang tinggi selama engine bekerja. Oleh sebab itu umumnya cylinder head dibuat dari besi tuang. Kendala yang ada saat ini yaitu proses pembuatan cylinder head kurang efektif dan efisien karena ketika menetapkan sudut untuk membuat reamer berbasis manual, selain itu setting benda kerja tidak otomatis sehingga membutuhkan waktu yang terlalu lama. Solusi dari permasalahan tersebut yaitu dengan adanya jig dan fixture. Metode penelitian yang digunakan adalah metodologi perancangan fixture (Society of Manufacturing Engineers). Berdasarkan hasil analisis, terdapat kelebihan dari jig dan fixture yang telah dirancang ulang yaitu: 1) memiliki stoper yang berfungsi untuk memberhentikan benda kerja, dengan sudut yang sudah ditentukan sehingga tidak perlu mensetting sudut kembali; 2) tidak mudah bergeser apabila fixture dipasang dan sejajar di meja frais; 3) terdapat dua engsel sehingga lebih balance; 4) pemasangan tidak rumit sehingga tidak memakan banyak waktu dalam pembuatan produk.Kata kunci: Jig and fixture; redesign; head cylinder The production process has evolved a lot with the introduction of innovative reliable manufacturing concepts. One of the engine components that are widely produced is the cylinder head. The cylinder head must withstand high temperatures and pressures while the engine is running. Therefore, generally the cylinder head is made of cast iron. The current constraint is that the cylinder head manufacturing process is less effective and efficient because when setting the angle to make the reamer a manual basis, besides that the workpiece setting is not automatic so it takes too long. The solution to this problem is the presence of jigs and fixtures. The research method used is the fixture design methodology (Society of Manufacturing Engineers). Based on the results of the analysis, there are advantages to the redesigned jig and fixture, namely: 1) it has a stoper which functions to stop the workpiece, at a predetermined angle so that there is no need to set the angle again; 2) it does not move easily when the fixture is installed and parallel to the milling table; 3) there are two hinges so that it is more balanced; 4) installation is not complicated so it does not take much time to manufacture the product.Keywords : Jig and fixture; redesign; head cylinder. DAFTAR RUJUKAN Basuki, B., Yoto., Suyetno A., & Tjiptady, B. C. (2020). Management Model of Manufacturing Workshop/Laboratory of Vocational Education in the Industry 4.0. 4th International Conference on Vocational Education and Training (ICOVET), Malang, Indonesia, 2020, pp. 127-130, doi: 10.1109/ICOVET50258.2020.9230188. Choong, G. Y. H., Canciani, A., & Defocatiis, D. S. A. (2020). An Adaptable Flexural Test Fixture for Miniaturised Polymer Specimens. Polymer Testing, 85, 106430. doi:10.1016/j.polymertesting.2020.106430 Craig, O., Picavea, J., Gameros, A., Axinte, D., & Lowth, S. (2020). Conformable Fixture Systems With Flexure Pins For Improved Workpiece Damping. Journal of Manufacturing Processes, 50, 638–652. doi:10.1016/j.jmapro.2019.12.045 Fonte, M., Reis, L., Infante, V., & Freitas, M. (2019). Failure Analysis of Cylinder Head Studs of a Four Stroke Marine Diesel Engine. Engineering Failure Analysis. doi:10.1016/j.engfailanal.2019.03.026 Gameros, A., Lowth, S., Axinte, D., Nagy-Sochacki, A., Craig, O., & Siller, H. R. (2017). State-Of-The-Art In Fixture Systems For The Manufacture And Assembly Of Rigid Components: A Review. International Journal of Machine Tools and Manufacture, 123, 1–21. doi:10.1016/j.ijmachtools.2017.07.004 Jing, G. X., Zhang, M. X., Qu, S., Pang, J. C., Fu, C. M., Dong, C., Zhang, Z. F. (2018). Investigation into diesel engine cylinder head failure. Engineering Failure Analysis, 90, 36–46. doi:10.1016/j.engfailanal.2018.03.008 Kamble, V. D., & Mathew, A. T. (2020). Brief Review of Methodologies for Creation of Cohesive Fixture Design. Materials Today: Proceedings, 22, 3353–3363. doi:10.1016/j.matpr.2020.04.285 Kampker, A., Bergweiler, G., Hollah, A., Lichtenthäler, K., & Leimbrink, S. (2019). Design and Testing of The Different Interfaces In A 3D Printed Welding Jig. Procedia CIRP, 81, 45–50. doi:10.1016/j.procir.2019.03.009 Krznar, N., Pilipović, A., & Šercer, M. (2016). Additive Manufacturing of Fixture for Automated 3D Scanning–Case Study. Procedia Engineering, 149, 197–202. doi:10.1016/j.proeng.2016.06.656 Kumar, S., Campilho, R. D. S. G., & Silva, F. J. G. (2019). Rethinking Modular Jigs’ Design Regarding the Optimization of Machining Times. Procedia Manufacturing, 38, 876–883. doi:10.1016/j.promfg.2020.01.169 Lu, R., Li, Y.-C., Li, Y., Jiang, J., & Ding, Y. (2020). Multi-agent Deep Reinforcement Learning Based Demand Response for Discrete Manufacturing Systems Energy Management. Applied Energy, 276, 115473. doi:10.1016/j.apenergy.2020.115473 Ma, S., Zhang, Y., Yang, H., Lv, J., Ren, S., & Liu, Y. (2020). Data-driven Sustainable Intelligent Manufacturing Based on Demand Response for Energy-Intensive Industries. Journal of Cleaner Production, 123155. doi:10.1016/j.jclepro.2020. 123155 Marsono, Yoto, Sutadji E., & Tjiptady, B. C. (2020). Career Development and Self-Efficacy Through Industrial Working Practice in Vocational Education," 4th International Conference on Vocational Education and Training (ICOVET), Malang, Indonesia, 2020, pp. 1-4, doi: 10.1109/ICOVET50258.2020.9230111 Nee, A. Y. C., Bhattacharyya, N., & Poo, A. N. (1987). Applying AI in Jigs and Fixtures Design. Robotics and Computer-Integrated Manufacturing, 3(2), 195–200. doi:10.1016/0736-5845(87)90102-5 Qolik, A., Nurmalasari, R., Yoto., & Tjiptady, B. C. (2020). The Role of Special Job Fair in Distributing Competitive Graduates in the 21st Century. 4th International Conference on Vocational Education and Training (ICOVET), Malang, Indonesia, 2020, pp. 115-118, doi: 10.1109/ICOVET50258.2020.9230064 Schuh, G., Bergweiler, G., Lichtenthäler, K., Fiedler, F., & Puente, R. S. (2020). Topology Optimisation and Metal Based Additive Manufacturing of Welding Jig Elements. Procedia CIRP, 93, 62–67. doi:10.1016/j.procir.2020.04.066 Seloane, W. T., Mpofu, K., Ramatsetse, B. I., & Modungwa, D. (2020). Conceptual Design of Intelligent Reconfigurable Welding Fixture for Rail Car Manufacturing Industry. Procedia CIRP, 91, 583–593. doi:10.1016/j.procir.2020.02.217 Siva, R., Siddardha, B., Yuvaraja, S., & Karthikeyan, P. (2020). Improving the productivity and tool life by fixture modification and renishaw probe technique. Materials Today: Proceedings, 24, 782–787. doi:10.1016/j.matpr.2020.04.386 Tjiptady, B. C., Rohman, M., Sudjimat, D. A., Ratnawati, D. (2020). Analisis Tegangan, Deformasi, dan Retak Pada Gas Turbine Blade dengan Metode Elemen Hingga. Jurnal Taman Vokasi. Vol 8, (2). doi : 10.30738/jtv.v8i2.8425 Tjiptady, B. C., Yoto., & Marsono. (2020). Entrepreneurship Development Design based on Teaching Factory to Improve the Vocational Education Quality in Singapore and Indonesia, 4th International Conference on Vocational Education and Training (ICOVET), Malang, Indonesia, pp. 130-134, doi: 10.1109/ICOVET50258.2020.9230222 Tohidi, H., & Algeddawy, T. (2016). Planning of Modular Fixtures in a Robotic Assembly System. Procedia CIRP, 41, 252–257. doi:10.1016/j.procir.2015.12.090 Vijaya, R. B., Elanchezhian, C., Rajesh, S., Jaya, P. S., Kumaar, B. M., & Rajeshkannan, K. (2018). Design and Development of Milling Fixture for Friction Stir Welding. Materials Today: Proceedings, 5(1), 1832–1838. doi:10.1016/j.matpr.2017.11.282
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Kang, Y., Y. Rong, and J. A. Yang. "Geometric and Kinetic Model Based Computer-Aided Fixture Design Verification." Journal of Computing and Information Science in Engineering 3, no. 3 (September 1, 2003): 187–99. http://dx.doi.org/10.1115/1.1607352.
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Computer-aided fixture design (CAFD) techniques have advanced to the point that fixture configurations can be generated automatically, for both modular fixtures and dedicated fixtures. Computer-aided fixture design verification (CAFDV) is a technique for verifying and improving existing fixture designs. This paper introduces a first comprehensive CAFDV framework which uses both geometric and kinetic models to verify locating completeness, locating accuracy, and fixturing stability. The models can be also used for locating tolerance assignment and the determination of minimum clamping force required in machining operations. The system is integrated with commercial CAD package and applied in industrial real-cases.
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Hou, Jiang-Liang, and A. J. C. Trappey. "Computer-aided fixture design system for comprehensive modular fixtures." International Journal of Production Research 39, no. 16 (January 2001): 3703–25. http://dx.doi.org/10.1080/00207540110060851.
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Vukelić, Đorđe, Goran Šimunović, Tomislav Šarić, Ivan Matin, Borislav Savković, Milovan Lazarević, and Branko Tadić. "COMPUTER-AIDED DESIGN AND OPTIMIZATION OF FIXTURES FOR PLASTIC PARTS MACHINING." Journal of Production Engineering 21, no. 1 (June 2018): 49–54. http://dx.doi.org/10.24867/jpe-2018-01-049.
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Samek, Andrzej, and Marian Kwatera. "The Functions and Structure Chucks and Fixtures for Computer Aided Design." IFAC Proceedings Volumes 28, no. 24 (October 1995): 139–43. http://dx.doi.org/10.1016/s1474-6670(17)46539-6.
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Nederbragt, W. W., and B. Ravani. "Design of Tactile Fixtures for Robotics and Manufacturing." Journal of Mechanical Design 119, no. 2 (June 1, 1997): 204–11. http://dx.doi.org/10.1115/1.2826237.
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This paper presents a theoretical framework for the design of tactile sensing fixtures for robotics and manufacturing. The framework presented uses group theory to analyze the symmetry of contact conditions on a fixture to evaluate a fixture design for referencing the sensor frame with respect to the fixture frame. Mechanical fixtures consisting of planar, spherical, and cylindrical surfaces are studied for their usefulness as part of referencing fixtures. The theory developed is used in guiding the design of a simple yet novel touch sensing fixture for part referencing and calibration in manufacturing and robotics.
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Zhang, Hong Shuang. "The Trend of Reconfigurable Pin-Type Fixture with Vacuum Suction Cups." Applied Mechanics and Materials 160 (March 2012): 273–76. http://dx.doi.org/10.4028/www.scientific.net/amm.160.273.
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Fixtures play a great role in manufacturing, and the quick changes in modern life lead to high need for changes in fixtures. The reconfigurable Pin-type Fixtures with Vacuum-suction-cup (PFV) developed broadly with the quickly progress of industrial technology. This paper mainly describes the design principles and main differences included in PFV. The characters of ideal PFV are drawn in line with the researches have been done in patents, companies and colleges. According to the actual needs of industry for fixture and the development of computer-aided-fixture-design technology, the trend of PFV in the next several decades is concluded in this paper.
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Jeng, Y. C., and K. F. Gill. "A CAD-based approach to the design of fixtures for prismatic parts." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 211, no. 7 (July 1, 1997): 523–38. http://dx.doi.org/10.1243/0954405971516473.
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The design scheme presented utilizes the knowledge representation and inference techniques from artificial intelligence and the geometric modelling technique for modular fixture design on a CAD (computer aided design) system. The fixture design problem is formulated in a hierarchical design structure. A systematic approach for selecting the locating and clamping positions on an automatically generated fixture configuration is outlined for the building of modular fixtures. Modular fixture elements are selected by considering the required function and geometric limitation. The generated fixture layout is then represented in the CAD system. To demonstrate the proposed approach, a prototype AutoCAFD (automatic computer aided fixture design) system is introduced and a practical example is presented.
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West, Harry, and Michael Gallo. "Design Through Manufacture: A Computer-Aided Design Advisor for the Manufacture of Submarine Hulls." Journal of Ship Production 6, no. 04 (November 1, 1990): 247–54. http://dx.doi.org/10.5957/jsp.1990.6.4.247.
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A computer graphics based advisory system has been developed to aid in the design and manufacture of submarine hulls. The design and manufacture advisor incorporates models of the materials (steel) and processes (bump forming, roll bending, welding, and fixturing) used for the manufacture of the hulls, and allows the user to explore the effect of different material qualities (described in terms of variances of thickness and yield strength), and different manufacturing parameters (punch penetration, punch spacing, and number of fixtures, for example) on the resulting quality (circularity) of the hull section. By "designing through manufacture" in this way the resulting design of the submarine hull section is not just a geometric representation of the desired shape of the hull, but incorporates explicit information about the materials and processes used to create the shape, and of the quality that results from the designer's choice of materials and processes.
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Prada, Rodolfo, and Shahram Payandeh. "On study of design and implementation of virtual fixtures." Virtual Reality 13, no. 2 (March 26, 2009): 117–29. http://dx.doi.org/10.1007/s10055-009-0115-4.
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Rong, Yiming (Kevin), and Yong Bai. "Automated Generation of Fixture Configuration Design." Journal of Manufacturing Science and Engineering 119, no. 2 (May 1, 1997): 208–19. http://dx.doi.org/10.1115/1.2831097.
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Flexible fixturing is a necessary aspect of Flexible Manufacturing Systems (FMS) and Computer-Integrated Manufacturing Systems (CIMS). Modular fixtures are most widely used in industry for job and batch production. Computer-Aided Fixture Design (CAFD) has become a research focus in implementing FMS and CIMS. Fixture configuration design is an important issue in the domain of CAFD. A review of the current research in CAFD indicates that a major problem impeding the automated generation of fixture configurations is the lack of studies on fixture structures. This paper investigates fundamental structures of dowel-pin based modular fixtures and fixturing characteristics of commonly used modular fixture elements. A Modular Fixture Element Assembly Relationship Graph (MFEARG) is designed to represent combination relationships between fixture elements. Based on MFEARG, algorithms are developed to search all suitable fixturing unit candidates and mount them into appropriate positions on a baseplate with interference checking. A prototype system for automated design of dowel-pin modular fixture configurations is presented in this paper. Fixture design examples are given at the end of the paper.
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Johansson, Christian. "Reverse Engineered Design Automation: Applying Knowledge Based Engineering Techniques to a Case of Automotive Fixtures Design Configuration." Proceedings of the Design Society: International Conference on Engineering Design 1, no. 1 (July 2019): 1583–92. http://dx.doi.org/10.1017/dsi.2019.164.
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AbstractIn the production of automotive body components, fixtures are an important part of the ongoing work on geometrical assurance. The fixture is uniquely defined for each component, and the design and configuration of these are time-consuming and takes a lot of effort. The objective with this paper is to explore the use of a design automation approach and application to semi-automate the configuration process of the fixture product. The paper presents an approach to automate the configuration of the fixtures in a flexible way, by reverse engineering the configuration of the fixture product from a generic blueprint that represents the expected outcome of the process, using a knowledge-based engineering approach applied to a computer aided design (CAD) environment. A reverse-engineered design automation toolbox for a CAD-software is developed. The toolbox is developed to lead a user through the configuration process, in the way that the experts want it done, end-to-end, making use of some unconventional solutions from a design automation perspective.
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Mihaylov, Oleg, and Galina Nikolcheva. "AN INTEGRATED RBR FIXTURE DESIGN SYSTEM." CBU International Conference Proceedings 5 (September 24, 2017): 1175–80. http://dx.doi.org/10.12955/cbup.v5.1091.
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Traditionally fixture design processes are costly and time-consuming when carried out manually. To try to reduce the negative features, we are creating a computer-aided fixture design system, integrated in the SolidWorks’ environment. This system uses rule-based reasoning in the form of If-Then-Else rules, incorporated in its VB.NET code. This paper presents our progress in the form of an interactive add-in program for locating parts. This program generates modular fixtures for locating prismatic or cylindrical parts, using rules and mathematical equations. Its usage can shorten the time needed for determining the type and position of every module of the fixture, their assembling, and inspection.
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Corrado, Andrea, and Wilma Polini. "Assembly design in aeronautic field: From assembly jigs to tolerance analysis." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, no. 14 (March 7, 2016): 2652–63. http://dx.doi.org/10.1177/0954405416635033.
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Tolerance analysis represents the best way to solve assembly problems in order to improve the quality and to reduce the costs. It is a critical step to design and to build a product such as an aircraft and its importance is grown up in the past years. This work presents a method for the tolerance analysis of an assembly involving free-form surfaces with large dimensions. The assembly is a tail beam, a structural component of an aircraft that is constituted by five parts of large dimensions. The influence of the tolerances applied to the five components of the tail beam on the value of the gap at the interfaces among the parts has been deeply investigated. A set of control points have been distributed on the free-form surfaces of the tail beam; its number and its distribution have been opportunely designed. Moreover, the influence of the tolerances on the other requirements of the tail beam connected with the motion drive has been studied. Tolerance analysis has involved the choice of the assembly tools and sequence too. The assembly jigs are mated with the assembly components through pins that are inserted into tooling holes located on the assembly components. The fit conditions have been modeled and the tolerances of the tooling hole have been opportunely chosen. Each tolerance of the tail beam components has been modeled by means of a probability density function. Monte Carlo approach has been used to obtain the statistical distribution of the assembly requirements, once dimensions and geometry of the tail beam components have been perturbed inside the tolerance ranges. Monte Carlo simulation has been carried out by a well-known computer-aided tolerance software, eM-Tolmate of UGS®.
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Choi, Eun-Hack Andrew, Jin-Ho Park, Tselmuun Erdenebat, Chung-Ju Hwang, and Jung-Yul Cha. "Surgical treatment of a skeletal Class III patient using customized brackets based on the CAD/CAM virtual orthodontic system." Angle Orthodontist 91, no. 5 (February 10, 2021): 692–704. http://dx.doi.org/10.2319/060820-528.1.
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ABSTRACT The computer-aided design/computer-aided manufacturing (CAD/CAM) virtual orthodontic system produces customized brackets, indirect bonding jigs, and archwires based on a three-dimensional virtual setup. In surgical cases, this system helps to visualize the final occlusion during diagnosis and to efficiently plan individualized presurgical orthodontic treatments. A 20-year-old female patient with a skeletal Class III malocclusion, maxillary protrusion, and lip protrusion was successfully treated with orthognathic surgery and orthodontic treatment with maxillary first premolar extractions. The CAD/CAM system was applied for efficient treatment, with a total active treatment time of 16 months. In this case report, the applicability of the CAD/CAM virtual orthodontic system for orthognathic surgery cases is demonstrated. Suggestions are also made to overcome the limitations and to maximize the advantages of this system during orthodontic treatment of patients undergoing orthognathic surgery.
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Thilmany, Jean. "Speedy Design." Mechanical Engineering 122, no. 01 (January 1, 2000): 60–61. http://dx.doi.org/10.1115/1.2000-jan-5.
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Engineers must make changes on the fly to keep race cars up to speed on the track. Westcoast, based in Anaheim, CA, designs and manufactures specialty components, mainly for the internal combustion engine industry. Engineers design the fixtures that hold the engine block in place during tooling in the same computer-aided design (CAD) program that they use for the block itself. Racing league rules prevent Nissan from changing key parts of the engine design, like the distance between the cylinders, but the company can vary other elements of the engine, such as deck height, oil passage diameters, and the main bearing journal diameters. By working out machining variables to ensure that production will go smoothly and quickly, Westcoast manufactures parts at the lowest cost possible, with no wasted production time. Westcoast is currently designing and manufacturing the most recent engine block upgrade, which will be ready for a spin around the track in May.
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Lichtenthäler, Kolja, Christian Höltgen, Falko Fiedler, and Georg Bergweiler. "Automatisierte Konstruktion von Schweißvorrichtungen im Karosseriebau/Automated Design of Welding Jigs for Body Shops." Konstruktion 73, no. 03 (2021): 63–69. http://dx.doi.org/10.37544/0720-5953-2021-03-63.
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Inhalt Im automobilen Karosseriebau sorgen starre, bauteilspezifische Schweißvorrichtungen für hohe Kosten im Falle von Produktänderungen, die vor allem in der Prototypen- und Vorserienphase häufig auftreten. Die Verwendung von additiv gefertigten Vorrichtungselementen stellt eine Möglichkeit dar, produktspezifische Elemente kostengünstiger bereitzustellen [1]. Für die schnellere, und damit auch kostengünstigere Umsetzung von auftretenden Änderungsanforderungen an Schweißvorrichtungen, stellt die Automatisierung des Konstruktionsprozesses eine vielversprechende Lösung dar [2]. Am Werkzeugmaschinenlabor WZL der RWTH Aachen University wurde zusammen mit der Firma PTC ein Automatisierungstool für die Konstruktion von Schweißvorrichtungen für das Computer-Aided Design (CAD)-System „Creo“ entwickelt, welche auf einem modularen Vorrichtungssystem basiert. Eine Bauteilbibliothek bestehend aus Standardelementen (Normprofile, Spanner und Aufnahmestiften), 2D-geschnittenen Metallblechen sowie additiv gefertigten bauteilspezifischen Vorrichtungselementen bildet hierfür die Konstruktionsgrundlage. Die additiv gefertigten Kunststoff-Strukturelemente ermöglichen durch ihre beliebig anpassbare Struktur eine beschleunigte Anpassbarkeit während der Schweißvorrichtungskonstruktion. Durch die Erprobung an einer Versuchsbaugruppe konnte die Fähigkeit der Konstruktionsprozess- Automati- sierung exemplarisch nachgewiesen werden. Die Abschätzung der Konstruktionsdauer zeigt das Potenzial einer Konstruk- tionszeitsenkung um bis zu 88,5 % im Vergleich zur manuellen, nicht automatisierten Vorrichtungskonstruktion. Durch den Einsatz der additiven Fertigung im Vorrichtungsbau lassen sich Herstellkosten von Vorrichtungselementen reduzieren.
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Shibaikin, Sergey D., and Evgeny G. Alekseev. "Software Library For The Lighting Fixtures Optical characteristics Calculation By The Computer-aided design System Kompas 3D." Issue 03-2021, no. 03-2021 (June 2021): 78–85. http://dx.doi.org/10.33383/2021-016.
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The advantages and disadvantages of existing solutions for calculating lighting fixtures (LF) are discussed in the paper. The methods for solving the global illumination problem are demonstrated. The most important illumination models used to calculate LFs have been analyzed. The Torrance-Sparrow model is used as the primary model of reflective surface. The triangulation method based on approximation of the LF surface by a grid of triangles is used to increase the efficiency of LF design and computation. The optical ray propagation in a 3D optical system was modelled using classical laws of optics and the Monte Carlo method. The structure and the main steps of working with the library for CAD Kompas are described. The approximation of LF surface for different types of light sources and reflector parameters is presented. The implementation of approximations with subsequent ray tracing has demonstrated a good convergence of the problem solution. The results of the study have the potential to be useful for design engineers involved in the design and calculation of LFs, as well as developers of applied software in the field of computer graphics and computer-aided design systems.
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Tsujimoto, A., WW Barkmeier, T. Takamizawa, MA Latta, and M. Miyazaki. "Influence of Thermal Cycling on Flexural Properties and Simulated Wear of Computer-aided Design/Computer-aided Manufacturing Resin Composites." Operative Dentistry 42, no. 1 (January 1, 2017): 101–10. http://dx.doi.org/10.2341/16-046-l.
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SUMMARY Objective: The purpose of this study was to evaluate the influence of thermal cycling on the flexural properties and simulated wear of computer-aided design/computer-aided manufacturing (CAD/CAM) resin composites. Methods: The six CAD/CAM resin composites used in this study were 1) Lava Ultimate CAD/CAM Restorative (LU); 2) Paradigm MZ100 (PM); 3) CERASMART (CS); 4) Shofu Block HC (SB); 5) KATANA AVENCIA Block (KA); and 6) VITA ENAMIC (VE). Specimens were divided randomly into two groups, one of which was stored in distilled water for 24 hours, and the other of which was subjected to 10,000 thermal cycles. For each material, 15 specimens from each group were used to determine the flexural strength and modulus according to ISO 6872, and 20 specimens from each group were used to examine wear using a localized wear simulation model. The test materials were subjected to a wear challenge of 400,000 cycles in a Leinfelder-Suzuki device (Alabama machine). The materials were placed in custom-cylinder stainless steel fixtures, and simulated localized wear was generated using a stainless steel ball bearing (r=2.387 mm) antagonist in a water slurry of polymethyl methacrylate beads. Simulated wear was determined using a noncontact profilometer (Proscan 2100) with Proscan and AnSur 3D software. Results: The two-way analysis of variance of flexural properties and simulated wear of CAD/CAM resin composites revealed that material type and thermal cycling had a significant influence (p<0.05), but there was no significant interaction (p>0.05) between the two factors. The flexural properties and maximum depth of wear facets of CAD/CAM resin composite were different (p<0.05) depending on the material, and their values were influenced (p>0.05) by thermal cycling, except in the case of VE. The volume losses in wear facets on LU, PM, and SB after 10,000 thermal cycles were significantly higher (p<0.05) than those after 24 hours of water storage, unlike CS, KA, and VE. Conclusion: The results of this study indicate that the flexural properties and simulated wear of CAD/CAM resin composites are different depending on the material. In addition, the flexural properties and simulated wear of CAD/CAM resin composites are influenced by thermal cycling.
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Metev, Hristo, Kalin Krumov, and Ali Gitan. "SELECTION OF LOCATORS IN AUTOMATED DESIGN OF FIXTURES FOR LOCATING WORKPIECES DURING MACHINING." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (June 16, 2021): 202–7. http://dx.doi.org/10.17770/etr2021vol3.6603.
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Using the systematic approach, the possible basing schemes of the workpieces in the machining attachments have been discovered and systematized with a view to their use in automated design. The analysis shows that the use of the proposed systematization in computer-aided design is significantly more rational, since the structure reflects the sequence of choice of the optimal basing scheme - analysis of the theoretical basing scheme, analysis of the geometry of the workpiece, formation of the possible list of the basing schemes. An analysis was performed with the help of which the criteria for geometric compatibility were revealed, allowing to make a choice of a basing scheme, satisfying the geometric shape of the workpiece. An algorithm for selection of locators has been developed. The development is part of a system for automated design of fixtures for locating of workpieces during machining.
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Jewell, G. W., and D. Howe. "Computer-aided design of magnetizing fixtures for the post-assembly magnetization of rare-earth permanent magnet brushless DC motors." IEEE Transactions on Magnetics 28, no. 5 (September 1992): 3036–38. http://dx.doi.org/10.1109/20.179709.
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Montanini, Roberto, Michele Scafidi, Giorgio Staiti, Antonia Marcianò, Leonardo D’Acquisto, and Giacomo Oteri. "Misfit evaluation of dental implant-supported metal frameworks manufactured with different techniques: Photoelastic and strain gauge measurements." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 230, no. 12 (November 11, 2016): 1106–16. http://dx.doi.org/10.1177/0954411916676192.
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This study aims to compare in-vitro the fitting accuracy of implant-supported metal frameworks used for full-arch orthodontic restoration. The hypotheses tested were as follows: (1) for a fixed implant morphology, strains developed within the framework depend on how the framework had been fabricated and (2) stresses transferred to the implant–bone interface are related to the amount of framework misfit. Metal frameworks were fabricated using four different manufacturing techniques: conventional lost-wax casting, resin cement luting, electrospark erosion, and computer-aided design/computer-aided manufacturing milling. Each framework was instrumented with three strain gauges to measure strains developed because of prosthetic misfit, while quantitative photoelastic analysis was used to assess the effect of misfit at the implant–resin interface. All the tested frameworks presented stress polarization around the fixtures. After screw tightening, significantly greater strains were observed in the lost-wax superstructure, while the lowest strains were observed in the luted framework, demonstrating consistent adaptation and passive fitting. No significant difference in stress distribution and marginal fit was found for bars fabricated by either computer-aided design/computer-aided manufacturing or spark erosion. This study suggested that, in spite of known limitations of in-vitro testing, direct luting of mesostructures and abutments should be the first clinical option for the treatment of complete edentulism, ensuring consistent passive fitting and effective cost–benefit ratio.
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Kumar, Manish, M. V. A. Raju Bahubalendruni, Bibhuti Bhusan Biswal, and Radharani Nayak. "Identification of Stable Configurations between Constituent Parts of an Assembly." Applied Mechanics and Materials 852 (September 2016): 595–601. http://dx.doi.org/10.4028/www.scientific.net/amm.852.595.
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There may be several feasible sequences of assembly operations for assembling a mechanical product. Requirement of fixtures for each assembly sequence are different and hence the assembly lead time. Assembly Sequence Planning (ASP) is the activity of finding sequence (s) of assembly operations which has improved productivity and reduced lead time. Generating such suitable assembly sequence (s) have always been a challenging research area because every product is special in terms of its design characteristics. Significant level of automation has been achieved in ASP but huge efforts are still required to enhance its performance through improvement of the existing algorithms and data structures. Identifying stable configurations between constituent parts of an assembly is one of such important concern to augment ASP. It helps reducing dependence on fixtures by driving the assembly process through more number of stable configuration stages making it economical in time and cost.The purpose of this piece of work is to formulate a method to obtain information rich stability predicate automatically through Computer Aided Design (CAD) interface for a mechanical product.The method is automatic and saves hours of time studying the assembly by a skilled and experienced assembly analyst.
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Boyle, Iain M., Kevin Rong, and David C. Brown. "CAFixD: A Case-Based Reasoning Fixture Design Method. Framework and Indexing Mechanisms." Journal of Computing and Information Science in Engineering 6, no. 1 (March 18, 2005): 40–48. http://dx.doi.org/10.1115/1.2161229.
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Fixtures accurately locate and secure a part during machining operations. Various computer-aided fixture design (CAFD) methods have been developed to reduce design costs associated with fixturing. One approach uses a case-based reasoning (CBR) method where relevant design experience is retrieved from a design library and adapted to provide a new design solution. Indexing design cases is a critical issue in CBR, and CBR systems can suffer from an inability to distinguish between cases if indexing is inadequate. This paper presents CAFixD, a CAFD methodology that adopts a rigorous approach to defining indexing attributes based upon axiomatic design functional requirement decomposition. A design requirement is decomposed in terms of functional requirements, physical solutions are retrieved and adapted for each individual requirement, and the design is then reconstituted to form a complete fixture design. This paper presents the CAFixD framework and operation, and discusses in detail the indexing mechanisms used.
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Landgraf, Mathias C. "FEA on the Assembly Line." Mechanical Engineering 121, no. 06 (June 1, 1999): 66–67. http://dx.doi.org/10.1115/1.1999-jun-6.
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Structural and dynamic analyses of a new machining fixture help Porsche AG get production up and running faster. Porsche contracted with KTW Konstruktion Technik K. Weisshaupt GmbH of Friedrichshafen, Germany, to design and produce the fixtures required to hold automobile motor parts in place during drilling and high-precision milling. It has been noted that using a 3-D computer-aided design (CAD) solid modeler can point out weaknesses before a design leaves the computer. In order to avoid the need for costly generations of prototypes prior to the casting process, Speedy Engineering in Immenstaad, Germany, used finite element analysis software to perform linear static and dynamic (vibration) analyses of the motor component fixture geometry within only a few days of its design, to determine displacements and eigenfrequencies of the geometry. The results of the static and dynamic analyses enabled Speedy to specify maximum working loads for •production, which guaranteed success with the first use of this fixture design.
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Lorenzetti, Massimo, Virginia Lorenzetti, Massimo Carossa, Davide Cavagnetto, and Federico Mussano. "Using a Preoperative Scan Digital Impression and a Digital Index to Build Immediate Interim Full-Arch Implant-Supported Prosthesis. A Case Report and Proof of Concept." Applied Sciences 11, no. 3 (January 22, 2021): 996. http://dx.doi.org/10.3390/app11030996.
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The transfer of information such esthetics and occlusion from the preoperative to the postoperative digital impression could reduce the time needed to build an immediately loaded full-arch not-guided rehabilitation and improve the quality of the immediate interim restoration. Based on the digital technology advances of the last years, the purpose of the present clinical report is to describe a novel digital workflow based on computer-aided design and computer-aided manufacturing aimed at fabricating an interim fixed full-arch restoration. The protocol entails recording preoperative information such as esthetics, the occlusal plane and the intermaxillary relationship in implant-supported complete rehabilitations before the surgical insertion of the fixtures. Then, the information is transferred to the postoperative impression using a digital index in the lower jaw and the palatal rugae in the upper jaw. Within the inherent limitations of a case report, the workflow was accurate, predictable, without errors from conventional protocols and was apparently characterized by low biological costs.
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Gaines, D. M., F. Castan˜o, and C. C. Hayes. "MEDIATOR: A Resource Adaptive Feature Recognizer that Intertwines Feature Extraction and Manufacturing Analysis." Journal of Mechanical Design 121, no. 1 (March 1, 1999): 145–58. http://dx.doi.org/10.1115/1.2829415.
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A deterrent to practical use of many feature extraction systems is that they are difficult to maintain, either because they depend on the use of a library of feature-types which must be updated when the underlying manufacturing resources change (e.g. tools and fixtures), or they rely on the use of task-specific post processors, which must also be updated. For such systems to become practical, it must be easy for a user to update the system to match the current resources. This paper presents MEDIATOR (Maintainable, Extensible Design and manufacturing Integration Architecture and TranslatOR). MEDIATOR is a resource adaptive feature extraction and early process planning system for 3-axis milling. A resource adaptive system is one that changes its behavior as the manufacturing resources in a shop change. MEDIATOR allows users to select from a standard set of tools and fixtures, and automatically identifies any changes in the features that result. It attains its resource adaptive behavior by blurring the line between feature extraction and process planning; descriptions of the manufacturing resources are used to directly identify manufacturable areas of the part. A non-programmer can easily update MEDIATOR by selecting different shop resources.
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Nederbragt, Walter W., and Bahram Ravani. "Enumeration of Contact Geometries for Kinematic Registration Using Tactile Sensing Fixtures." Journal of Mechanical Design 128, no. 1 (May 5, 2005): 34–45. http://dx.doi.org/10.1115/1.2118731.
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This paper uses group theory for enumeration of contacts between geometric elements necessary for kinematic registration or part referencing in robotics. The results are applied to type synthesis of tactile sensing mechanical fixtures. Kinematic registration is an important step in robot calibration and in data driven automation. Although the scope of the paper is limited to geometric contacts involving points, lines, planar surfaces, cylindrical surfaces, and spherical surfaces, the techniques developed are general and can be applied to other geometric features and non-tactile sensing elements used in robotic calibration and part referencing.
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Ma, Junkun, Keith Coogler, and Minjae Suh. "Inquiry-based learning: Development of an introductory manufacturing processes course based on a mobile inverted pendulum robot." International Journal of Mechanical Engineering Education 48, no. 4 (May 1, 2019): 371–90. http://dx.doi.org/10.1177/0306419019844257.
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This paper describes the development of an innovative introductory manufacturing processes course designed to expose students to a broad overview of fundamental concepts, methods, procedures, tools, and equipment used in the manufacturing industry. Based on an educational mobile inverted pendulum robot, students are introduced to product design and prototyping by identifying an existing problem with a component in the robot, redesigning the component using computer aided design software, and then building a prototype using additive manufacturing methods. Subsequently, a set of hypothetical design requirement changes is imposed, and various design methods and manufacturing processes that can be used to make components to satisfy these new requirements are discussed. Topics covered include integrated product design, additive manufacturing prototyping based on different technologies, plastic injection molding, sand casting, and fundamentals of both computer aided manufacturing and computer numerical control machining. Tools, fixtures, and accessories required in these processes, as well as associated challenges, are also discussed. This course adapts the inquiry-based learning active learning pedagogical approach and focuses on the development of students’ ability to conduct analytical analysis and to apply a knowledge of mathematics, science, engineering, and technology to solve practical engineering technology problems. As an introductory course designed to be offered to freshman level students, this course engages students in engineering technology related topics and stimulates their interest in manufacturing related subjects. It helps with improving the engineering student retention rate and serves as a pathway connecting students to more advanced specialized manufacturing courses such as computer numerical control machining technology. This paper presents course materials developed and student feedback as well as their evaluation of the course effectiveness based on a summative questionnaire-style survey from the first cohort of students.
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Álvarez-Botero, Germán, Reydezel Torres-Torres, and Roberto S. Murphy-Arteaga. "Modeling and parameter extraction of test fixtures for MOSFET on-wafer measurements up to 60 GHz." International Journal of RF and Microwave Computer-Aided Engineering 23, no. 6 (November 15, 2012): 655–61. http://dx.doi.org/10.1002/mmce.20701.
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Cattoni, Francesca, Luca Chirico, Alberto Merlone, Michele Manacorda, Raffaele Vinci, and Enrico Felice Gherlone. "Digital Smile Designed Computer-Aided Surgery versus Traditional Workflow in “All on Four” Rehabilitations: A Randomized Clinical Trial with 4-Years Follow-Up." International Journal of Environmental Research and Public Health 18, no. 7 (March 26, 2021): 3449. http://dx.doi.org/10.3390/ijerph18073449.
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The aim of the present study was to evaluate and compare the traditional “All on Four” technique with digital smile designed computer-aided “All on Four” rehabilitation; with a 4-years follow-up. The protocol was applied to a total of 50 patients randomly recruited and divided in two groups. Digital protocol allows for a completely virtual planning of the exact position of the fixtures, which allows one to perform a flapless surgery procedure with great accuracy (mini-invasive surgery) and also it is possible to use virtually planned prostheses realized with Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) (methods for an immediate loading of the implants. After 4 years from the treatments 98% of success were obtained for the group of patients treated with the traditional protocol and 100% for the digital protocol. At each time interval a significant difference in peri-implant crestal bone loss between the two groups was detected; with an average Marginal Bone Loss (MBL) at 4 years of 1.12 ± 0.26 mm in the traditional group and 0.83 ± 0.11 mm in the digital group. Patients belonging to the digital group have judged the immediate loading (92%), digital smile preview (93%), the mock-up test (98%) and guided surgery (94%) as very effective. All patients treated with a digital method reported lower values of during-surgery and post-surgery pain compared to patients rehabilitated using traditional treatment. In conclusion, the totally digital protocol described in the present study represents a valid therapeutic alternative to the traditional “All on Four” protocol for implant-supported rehabilitations of edentulous dental arches.
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Bugbee, William D., Hideki Mizu-uchi, Shantanu Patil, and Darryl D'Lima. "Accuracy of Implant Placement Utilizing Customized Patient Instrumentation in Total Knee Arthroplasty." Advances in Orthopedics 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/891210.
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Customized patient instrumentation (CPI) combines preoperative planning with customized cutting jigs to position and align implants during total knee arthroplasty (TKA). We compared postoperative implant alignment of patients undergoing surgery with CPI to traditional TKA instrumentation for accuracy of implant placement. Twenty-five consecutive TKAs using CPI were analyzed. Preoperative CT scans of the lower extremities were segmented using a computer program. Limb alignment and mechanical axis were computed. Virtual implantation of computer-aided design models was done. Postoperative coronal and sagittal view radiographs were obtained. Using 3D image-matching software, relative positions of femoral and tibial implants were determined. Twenty-five TKAs implanted using traditional instrumentation were also analyzed. For CPI, difference in alignment from the preoperative plan was calculated. In the CPI group, the mean absolute difference between the planned and actual femoral placements was 0.67° in the coronal plane and 1.2° in the sagittal plane. For tibial alignment, the mean absolute difference was 0.9° in the coronal plane and 1.3° in the sagittal plane. For traditional instrumentation, difference from ideal placement for the femur was 1.5° in the coronal plane and 2.3° in the sagittal plane. For the tibia, the difference was 1.8° in the coronal plane. CPI achieved accurate implant positioning and was superior to traditional TKA instrumentation.
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Dhobale, Aditya. "Challenges Faced While Designing Body in White." International Journal for Research in Applied Science and Engineering Technology 9, no. 9 (September 30, 2021): 49–56. http://dx.doi.org/10.22214/ijraset.2021.37916.
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Abstract: Construction of Body in White (BiW) revolves around plenty of challenges. Ranging from BiW fixtures to curbing weight of Body in White sheet metal design. This paper discusses about all the design aspects in BiW manufacturing in automobile and confronting challenges that occurs. At present, lots of existing theories are being applied and efforts to improve the same are being made. This paper provides a path on how components can be developed and make necessary improvements. CAE (Computer Aided Engineering) tools have been used for FEA (Finite Element Analysis) and also an example of stress analysis of automotive chassis is given. An outcome depending on behaviour of loads acting on frame is drawn. The importance of hollow tubes, tubes of different- cross sections to counter weight and ease the designing of BiW frame have been proposed. This paper also provides insight on safety parameters with current construction of tubular frame chassis. Other solutions such as hybrid tubes, foam padding and plastic trim have been pointed out in this paper. Keywords: CAE, FEA, manufacturing, loads, tubes, cycle-time, cross-section.
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Yakovenko, Ihor Eduardovich, Alexandr Anatolievich Permyakov, and Oleksandr Sergvyovich Kharchenko. "DEVELOPMENT OF THE COMPONENT BASE OF UNIFIED ASSEMBLY AND PARTS OF INSTALLATION CLAMPING DEVICES." Bulletin of the National technical university "Kharkiv Polytechnic Institute" Series: Techniques in a machine industry, no. 1 (July 28, 2022): 21–26. http://dx.doi.org/10.20998/2079-004x.2022.1(5).03.
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The issues of unification of units and elements of special equipment were further developed in the work. Issues of a theoretical approach to the creation of an element base of unified assemblies and parts for existing layout schemes for mounting and clamping devices of equipment built on the principles of aggregation are considered. in order to subsequently minimize the cost of design and production. The authors propose a two-stage methodology for unifying fixture elements in order to create a reference and regulatory framework for such elements. At the first stage, based on the analysis of the functional purpose of the structural elements of various layout schemes of devices, a list of parts is established, the unification of which is possible and expedient. At the second stage, based on the strength analysis of the selected elements and the analysis of statistical information on the geometric parameters of the installed workpieces for various layout schemes of fixtures, the number of standard sizes and geometric parameters of these parts are determined. This approach allows you to create a constantly updated and edited database of unified fixture elements, which can be used in the process of computer-aided design.
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Shin, C. K., and H. S. Cho. "On the generation of robotic assembly sequences based on separability and assembly motion stability." Robotica 12, no. 1 (January 1994): 7–15. http://dx.doi.org/10.1017/s0263574700018130.
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This paper presents a method for the automatic generation of robotic assembly sequences based on the verification of a disassemblability for a part to be disassembled. To derive the disassemblability of a candidate part, we first inference collision free assembly directions by extracting separable directions for the part and calculating the separability which gives information as to how the part can be easily separated. Using the result, we determine the disassemblability defined in terms of the separability and stability costs. The separability cost represents a facility of the part disassembly operation, while the stability cost represents a degree of the stability for the base assembly motion which gives a guidance for design of jig/fixture. The proposed method provides a potentially local optimal solution for finding a cost effective assembly plan, and the feasibility of generating robot motion programs by evaluating separable directions in flexible manufacturing applications. A case study is given to illustrate the concepts and procedure of the proposed scheme.
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Huang, Zhengdong, and Derek Yip-Hoi. "Parametric Modeling of Part Family Machining Process Plans From Independently Generated Product Data Sets." Journal of Computing and Information Science in Engineering 3, no. 3 (September 1, 2003): 231–42. http://dx.doi.org/10.1115/1.1602489.
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Parametric modeling has become a widely accepted mechanism for generating data set variants for product families. These data sets include geometric models and feature-based process plans. They are created by specifying values for parameters within feasible ranges that are specified as constraints in their definition. These ranges denote the extent or envelope of the product family. Increasingly, with globalization the inverse problem is becoming important: Given independently generated product data sets that on observation belong to the same product family, create a parametric model for that family. This problem is also of relevance to large companies where independent design teams may work on product variants without much collaboration only to later attempt consolidation to optimize the design of manufacturing processes and systems. In this paper we present a methodology for generating a parametric representation of the machining process plan for a part family through merging product data sets generated independently from members of the family. We assume that these data sets are feature-based machining process plans with relationships such as precedences between the machining steps for each feature captured using graphs. Since there are numerous ways in which these data sets can be merged, we formulate this as an optimization problem and solve using the A* algorithm. The parameter ranges generated by this approach will be used in the design of tools, fixtures, material handling automation and machine tools for machining the given part family.
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Yue, Jianpeng, Jaime A. Camelio, Melida Chin, and Wayne Cai. "Product-Oriented Sensitivity Analysis for Multistation Compliant Assemblies." Journal of Mechanical Design 129, no. 8 (July 25, 2006): 844–51. http://dx.doi.org/10.1115/1.2735341.
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Dimensional variation in assembled products directly affects product performance. To reduce dimensional variation, it is necessary that an assembly be robust. A robust assembly is less sensitive to input variation from the product and process components, such as incoming parts, subassemblies, fixtures, and welding guns. In order to effectively understand the sensitivity of an assembly to input variation, an appropriate set of metrics must be defined. In this paper, three product-oriented indices, including pattern sensitivity index, component sensitivity index, and station sensitivity index, are defined. These indices can be utilized to measure the variation influence of a pattern, an individual part, and/or component, and components at a particular station to the dimensional quality of a final assembly. Additionally, the relationships among these sensitivity indices are established. Based on these relationships, the ranges of the sensitivity indices are derived. Finally, a case study of a sheet metal assembly is presented and discussed to illustrate the applicability of these metrics.
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PENG, MATTHEW JIAN-QIAO, HONGWEN XU, HAI-YAN CHEN, XIANGYANG JU, YONG HU, ASHRAF AYOUB, BALVINDER KHAMBAY, YUEMING GUO, and BO BAI. "COMPARATIVE ANALYSIS FOR THREE FIXTURES OF PAUWELLS-II BY THE BIOMECHANICAL FINITE ELEMENT METHOD." Journal of Mechanics in Medicine and Biology 20, no. 01 (December 9, 2019): 1950079. http://dx.doi.org/10.1142/s0219519419500799.
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Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for [Formula: see text](3LS) is the least; Internal-fixator stress (MPa) for [Formula: see text]; Integral stress (MPa) for [Formula: see text]; displacement of femoral head (mm) for a[Formula: see text](DHS+LS) = 0.735; displacement of femoral shaft (mm) for [Formula: see text]; and displacement of fixators for [Formula: see text]. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.
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Sundararajan, V., and Paul K. Wright. "Identification of Multiple Feature Representations by Volume Decomposition for 2.5-Dimensional Components." Journal of Manufacturing Science and Engineering 122, no. 1 (May 1, 1999): 280–90. http://dx.doi.org/10.1115/1.538905.
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Decomposition of computer-aided design models into features that can be directly manufactured and easily translated from one representation to another has been recognized as a necessity for robust automated process planning systems. The algorithms presented here yield multiple representations of features that can be used to generate plans that are easily and efficiently manufacturable by milling processes. Features are recognized from the faces of a prismatic stock by first identifying missing regions on the external faces of the stock and then recursively descending into the part. Each missing region corresponds to a feature. As the projection of the feature is swept into the part, changes in the cross-section are identified. These denote the beginning of new features which become children of the original feature. This process yields a set of six trees, each of which resembles a depth-first search tree and is a partial ordering of features within a setup. Multiple representations are investigated for those features that are accessible from more than one direction. Corresponding features in the different trees are linked by arcs, thus yielding a feature graph. The feature graph can then be used to generate optimal features for machining depending on design or manufacturing requirements such as fixtures, tolerances, corner radii, and tool accessibility. [S1087-1357(00)01901-8]
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Li, Linzhu, and Magued Iskander. "Visualization of Interstitial Pore Fluid Flow." Journal of Imaging 8, no. 2 (January 30, 2022): 32. http://dx.doi.org/10.3390/jimaging8020032.
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Pore scale analysis of flow through porous media is of interest because it is essential for understanding internal erosion and piping, among other applications. Past studies have mainly focused on exploring macroscopic flow to infer microscopic phenomena. An innovative method is introduced in this study which permits visualization of interstitial fluid flow through the pores of a saturated synthetic transparent granular medium at the microscale. Several representative images of Ottawa sand were obtained using dynamic image analysis (DIA), for comparison with flow through perfect cylinders. Magnified transparent soil particles made of hydrogel were cast in 3D printed molds. Custom 3D printed jigs were employed for accurate positioning of the particles to ensure that particles have the same flow area within the soil. The pore fluid was embedded with silver-coated hollow microspheres that allowed for their florescence and tracking their movement within the model when illuminated by a laser light source. Images of the flow were captured from the model using a high-speed camera. This, along with particle image velocimetry (PIV) provided for the velocity and direction analysis of fluid flow movements within the pore space of a planar 2D model. Comparison of interstitial flow through homogeneous porosity-controlled Ottawa-shaped and cylindrical particles demonstrates that the magnitude of turbulence is related to particle roundness.
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Dhanda, Aaina, Tarun Kalra, Manjit Kumar, Ajay Bansal, and Ruchi Sharma. "Implant Impression Making: Take-Off Guide for Beginners." Dental Journal of Advance Studies 09, no. 03 (November 10, 2021): 121–27. http://dx.doi.org/10.1055/s-0041-1736489.
Full textAbstract:
AbstractDental implants are fixtures that constitute for the replacements of the root of a missing natural tooth. Dental implant therapy has been widely used for the restoration of partially and fully edentulous patients. The implant literature emphasizes the importance of a passively fitting prosthesis to prevent prosthodontic complications or even loss of fixture integration. Failure to achieve a passively fitting prosthesis and force tightening of superstructure may result in complications such as abutment, framework, and gold screw loosening or fracture. Various materials that can be used for making an implant impression are polyether, polyvinylsiloxane, condensation silicone, polysulfide, irreversible hydrocolloid material, and various others. There are various studies in relation to the accuracy of these impression materials out of which various scientists concluded different results with most studies stating polyether with the maximum amount of dimensional accuracy in comparison to other materials. An accurate implant impression plays a significant role and serves as a starting point in the process of producing good working casts. Thus, the accuracy of impression techniques becomes a significant issue in consideration of passive fit. Reproduction of intraoral relationship of implants through impression procedures is the first step in achieving accurate fit prosthesis. This transference is still complicated by the number, angulation, depth, and position of implants. The advent of computer-aided design/computer-assisted manufacturing technology improved the framework fabrication procedures and has increased the precision of fit of implant prosthesis.
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Linder, K. J., and R. J. Cipra. "A Strategy for Determining the Stability of Parts Fixtured Under Three-Point Frictional Constraint." Journal of Mechanical Design 115, no. 4 (December 1, 1993): 863–70. http://dx.doi.org/10.1115/1.2919280.
Full textAbstract:
Flexible assembly systems require flexible fixtures to constrain parts in a stable fashion in order to perform assembly operations. This paper gives a systematic strategy that uses graphical techniques to determine the stability of parts fixtured under a particular type of three-point frictional constraint. The two inputs into the analysis method are the geometry and frictional properties of the fixturing system. No information about the applied clamping force is necessary for the method to determine stability. The strategy finds all kinematically possible motions of a part based on the existence of instant centers. Then for subsets of these motions it determines if static equilibrium exists in order to find out which of these motions cannot occur. Finally, the method classifies a part into one of three categories: stable, not stable, or unstable. If it is determined that there are no possible unstable motions, then the part is stable. But if it is determined that the part will move in one-point unstable motion then it is unstable. If any two- or three-point unstable motions are determined to be possible, then the part is classified as not stable. Although some of the parts in the not stable category will be unstable, there are other cases in this classification in which it is not known whether one of the unstable modes will occur. These are indeterminate cases in which the stability of the part cannot be determined. However, the method can determine those cases in which the part is stable which makes it a useful fixture analysis tool.
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Lin, Hui-Ting, Jerry Chin-Yi Lin, Eisner Salamanca, Odontuya Dorj, Yu-Hwa Pan, Yi-Fan Wu, Yung-Szu Hsu, Chih-Yuan Fang, and Wei-Jen Chang. "Marginal Bone Level Evaluation of Fixed Partial Dental Prostheses Using Preformed Stock versus CAD/CAM Customized Abutments." Journal of Personalized Medicine 12, no. 7 (June 27, 2022): 1051. http://dx.doi.org/10.3390/jpm12071051.
Full textAbstract:
Background: The maintenance of marginal bone levels around dental implants is an important criterion for evaluating the success of implants. Although computer-aided design/computer-aided manufacturing (CAD/CAM) customized abutments (CAs) provide more flexible solutions, compared with the original preformed stock abutments (PAs), there are dimensional tolerances and underlying drawbacks in the production of CAD/CAM CAs, which may change the tightness and seamless connection between fixtures and abutments set by the manufacturer and then affect the long-term stability of the abutments. This study aimed to examine the change in both mesial and distal bone levels using digital periapical radiographs to evaluate the difference between CAD/CAM CAs and original PAs.Material and methods: Radiographs were taken before delivery; after functional loading for 1 month; and after 3, 6, and 12 months; and the vertical marginal bone levels (vMBLs) of both the mesial and distal surrounding implant bones were measured. All data are presented as means ± standard errors and were analyzed using Student’s t-test. A p-value < 0.05 was judged to represent a significant difference. Results: A total of 57 implants in 50 patients were divided into 22 CAD/CAM CAs and 35 original stock abutments. The PAs appeared to have a more stable bone level. By contrast, the amount of bone level change in the CAs was higher than that in the PAs. The change in the vMBL of the CAs was significantly more than that of the PAs after functional loading for 1 month (p = 0.006), 3 months (p = 0.013), 6 months (p = 0.014), and 12 months (p = 0.002). In contrast, the distal marginal bone level was lower than the mesial marginal bone level in any period. Nevertheless, the bone levels of the CAs and PAs in any period were comparable with no significant difference. Conclusions: Significant differences were found between the mesial and distal bone levels in the PAs. The CAD/CAM CAs showed a significantly greater bone level change than the original stock abutments after functional loading.