Journal articles: 'Joint simulation-optimisation'

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Purnomo, Muhammad Ridwan Andi, Dzuraidah Abdul Wahab, and Ade Rizqy Anugerah. "Optimisation of the Single-Vendor Single-Buyer Supply Chain System under Fuzzy Demand Using Optimisation–Simulation Closed Loop Technique." Mathematical Modelling of Engineering Problems 9, no. 5 (December 13, 2022): 1343–51. http://dx.doi.org/10.18280/mmep.090524.

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This research aims to model and optimise the most applicable supply chain system, which is a single-vendor single-buyer system with fuzzy buyer demand. An optimisation model of the supply chain system under consideration is built by formulating the objective function, which is minimising the joint total cost between a buyer and a vendor. The model is developed on the basis of a simulation system, and optimisation is carried out by utilising a Genetic Algorithm that has been embedded in the simulation system. This technique is called optimisation–simulation closed loop. The vendor actual condition, which deals with uncertain demands from the main buyer and other small buyers, is considered. To analyse timely supply chain events, a simulation system is developed. A new optimisation model for the single-vendor single-buyer supply chain system with fuzzy demand is developed on the basis of the simulation system. The use of optimisation–simulation closed loop is also a new finding. In this study, the optimisation model of the supply chain under consideration is developed by taking into account a specific condition in which the vendor receives demands from the main buyer and other small buyers. Naturally, buyer demand is uncertain and has been modelled using a fuzzy set. The use of optimisation–simulation closed loop enables the supply chain to make the optimum decision when at the steady state condition.

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Volsem, Sofie Van. "Joint optimisation of all inspection parameters for multistage processes: evolutionary algorithm and simulation." International Journal of Innovative Computing and Applications 2, no. 3 (2010): 170. http://dx.doi.org/10.1504/ijica.2010.033648.

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Indukuri, Rama pavan Kumar Varma, Rama Murty Raju P., Srinivasa Rao Ch, and Rajesh S. "Process Parameters Optimisation and Numerical Simulation of Laser Beam Welded Butt Joints of Maraging Steel." International Journal of Automotive and Mechanical Engineering 19, no. 2 (June 28, 2022): 9709–20. http://dx.doi.org/10.15282/ijame.19.2.2022.07.0749.

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Maraging steels are ultra-high strength iron nickel-based alloys which are used in military applications like rocket motor casings, missiles, and ship hulls. In the current work, maraging steels of 250 grade butt joints with 2 mm thickness are welded by using Nd:YAG laser. The experiments were designed and conducted using the L16 orthogonal array. Various welding parameters selected for the current work are laser power, welding speed, and focal position, whereas tensile strength, hardness and depth of penetration were considered as the output responses. The influence of process variables on weld bead morphology was analysed experimentally. The microstructure, mechanical characteristics and numerical analysis of the optimum joint were also investigated. Analysis of variance (ANOVA) was used to determine the effect of different variables on tensile strength and depth of penetration. According to the results, laser power and welding speed are essential factors for tensile strength. The depth of penetration is strongly influenced by welding speed, focal position, and laser power. In order to predict the weld bead, finite element analysis was performed on ABAQUS 3D finite element software. The results reveal that finite element simulation and experimental observations are matched.

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Nyong-Bassey, Bassey, and Ayebatonye Marttyns Epemu. "Inverse Kinematics Analysis of Novel 6-Dof Robotic Arm Manipulator for Oil and Gas Welding Using Grey Wolf Algorithm." International Journal on Robotics, Automation and Sciences 4 (July 8, 2022): 13–22. http://dx.doi.org/10.33093/ijoras.2022.4.3.

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his paper presents a grey-wolf algorithm for solving the inverse kinematics of a newly designed 6-degree-of-freedom robotic arm for oil and gas pipeline welding which has not been used in the literature. Consequently, due to the robot’s multiple joints with compounding combinatory possibilities of joint angles, analysis of the inverse kinematics is relatively complex. In this research, grey-wolf algorithm, a swarm-based meta-heuristic algorithm, has been used to solve for the inverse kinematics of the robotic arm with respect to tracking a rectangular trajectory with six sets of waypoints in the 3D [X, Y, Z] space. The results were further analyzed in terms of the accuracy of the position of end effector from the accurate position of the rectangular target trajectory via a mean squared error cost function. Furthermore, results of comparison between the grey-wolf algorithm and the particle swarm optimisation, an alternate swarm algorithm with respect to position error from the inverse kinematics task is also presented. The results obtained via simulation clearly demonstrates the superior performance of the grey-wolf algorithm compared to particle swarm optimisation with respect to the solving an inverse kinematics task

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Xu, Enyong, Shuilong He, Weiguang Zheng, Tao Tang, Chao Li, and Qibai Huang. "Research on Cab Vibration Control Based on Parameter Hierarchical Interaction Model." Shock and Vibration 2020 (October 21, 2020): 1–15. http://dx.doi.org/10.1155/2020/8841598.

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The vibration level of a cab affects the passenger’s ride comfort and safety significantly. It is of great importance to control the vibration level of cabs under various driving conditions. The associated vibration transfer paths of cabs are studied by using a hierarchical analysis method of a parameter index. The multiobjective design analysis is carried out by using the multiparameter joint optimisation design. Further, the optimal control of the cab vibration level is obtained from a full-condition simulation environment. Additionally, a multibody vehicle model is established. The simulation analysis under multiple working conditions is conducted. The optimal parameter distribution of the cab mounting structure was established by analysing the influence of the design parameters and experimental verification. This greatly improves the comfort of the cab.

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Killen, Bryce A., Antoine Falisse, Friedl De Groote, and Ilse Jonkers. "In Silico-Enhanced Treatment and Rehabilitation Planning for Patients with Musculoskeletal Disorders: Can Musculoskeletal Modelling and Dynamic Simulations Really Impact Current Clinical Practice?" Applied Sciences 10, no. 20 (October 16, 2020): 7255. http://dx.doi.org/10.3390/app10207255.

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Over the past decades, the use of computational physics-based models representative of the musculoskeletal (MSK) system has become increasingly popular in many fields of clinically driven research, locomotor rehabilitation in particular. These models have been applied to various functional impairments given their ability to estimate parameters which cannot be readily measured in vivo but are of interest to clinicians. The use of MSK modelling and simulations allows analysis of relevant MSK biomarkers such as muscle and joint contact loading at a number of different stages in the clinical treatment pathway in order to benefit patient functional outcome. Applications of these methods include optimisation of rehabilitation programs, patient stratification, disease characterisation, surgical pre-planning, and assistive device and exoskeleton design and optimisation. This review provides an overview of current approaches, the components of standard MSK models, applications, limitations, and assumptions of these modelling and simulation methods, and finally proposes a future direction.

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Ye, Xuan, Lan Luo, Li Hou, Yang Duan, and Yang Wu. "Laser Ablation Manipulator Coverage Path Planning Method Based on an Improved Ant Colony Algorithm." Applied Sciences 10, no. 23 (December 3, 2020): 8641. http://dx.doi.org/10.3390/app10238641.

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Coverage path planning on a complex free-form surface is a representative problem that has been steadily investigated in path planning and automatic control. However, most methods do not consider many optimisation conditions and cannot deal with complex surfaces, closed surfaces, and the intersection of multiple surfaces. In this study, a novel and efficient coverage path-planning method is proposed that considers trajectory optimisation information and uses point cloud data for environmental modelling. First, the point cloud data are denoised and simplified. Then, the path points are converted into the rotation angle of each joint of the manipulator. A mathematical model dedicated to energy consumption, processing time, and path smoothness as optimisation objectives is developed, and an improved ant colony algorithm is used to solve this problem. Two measures are proposed to prevent the algorithm from being trapped in a local optimum, thereby improving the global search ability of the algorithm. The standard test results indicate that the improved algorithm performs better than the ant colony algorithm and the max–min ant system. The numerical simulation results reveal that compared with the point cloud slicing technique, the proposed method can obtain a more efficient path. The laser ablation de-rusting experiment results specify the utility of the proposed approach.

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Menser, Bernd, Dirk Manke, Detlef Mentrup, and Ulrich Neitzel. "A MONTE-CARLO SIMULATION FRAMEWORK FOR JOINT OPTIMISATION OF IMAGE QUALITY AND PATIENT DOSE IN DIGITAL PAEDIATRIC RADIOGRAPHY." Radiation Protection Dosimetry 169, no. 1-4 (November 30, 2015): 371–77. http://dx.doi.org/10.1093/rpd/ncv483.

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Chen, H., X. Fang, Z. Zhang, X. Xie, H. Nie, and X. Wei. "Parameter optimisation of a carrier-based UAV drawbar based on strain fatigue analysis." Aeronautical Journal 125, no. 1288 (February 11, 2021): 1083–102. http://dx.doi.org/10.1017/aer.2021.1.

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ABSTRACTCarrier-based unmanned aerial aircraft (UAV) structure is subjected to severe tensile load during takeoff, especially the drawbar, which affects its fatigue performance and structural safety. However, the complex structural features pose great challenges for the engineering design. Considering this situation, a structural design, fatigue analysis, and parameters optimisation joint working platform are urgently needed to solve this problem. In this study, numerical analysis of strain fatigue is carried out based on the laboratory fatigue failure of the carrier-based aircraft drawbar. Taking the sensitivity of drawbar parameters to stress and life into account and optimum design of drawbar with fatigue life as a target using the parametric method, this study also includes cutting-edge parameters of milling cutters, structural details of the drawbar and so on. Then an experimental design is applied using the Latin hypercube sampling method, and a surrogate model based on RBF neural network is established. Lastly, a multi-island genetic algorithm is introduced for optimisation. The results show that the error between the obtained optimal solution and simulation is 0.26%, while the optimised stress level is reduced by 15.7%, and the life of the drawbar is increased by 122%.

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Zahedi-Hosseini, Farhad, Philip Scarf, and Aris Syntetos. "Joint optimisation of inspection maintenance and spare parts provisioning: a comparative study of inventory policies using simulation and survey data." Reliability Engineering & System Safety 168 (December 2017): 306–16. http://dx.doi.org/10.1016/j.ress.2017.03.007.

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Zalzala, A. M. S., and A. S. Morris. "Structured Motion Planning in the Local Configuration Space." Robotica 9, no. 1 (January 1991): 81–92. http://dx.doi.org/10.1017/s0263574700015599.

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SUMMARYThe minimum-time motion of robot manipulators is solved by defining a suitable time history for the arm end-effector to traverse. As the planning is performed in the configuration space, the uniqueness of the proposed algorithm emerges from the combination of both cubic and quadratic polynomial splines. Furthermore, the highly efficient time optimisation procedure could be applied to local segments of each joint trajectory, leading to a significant reduction of the travelling time. In addition, the ability to perform a search in the work space is granted, exploiting all possible options for an optimum motion. The method proposed considers all realistic physical limitations inherent in the manipulator design, in addition to any geometric constraints imposed on the path. Simulation programs have been written, and results are reported for the Unimation PUMA 560 robot manipulator.

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Gupta, Sagar, Abhaya Pal Singh, Dipankar Deb, and Stepan Ozana. "Kalman Filter and Variants for Estimation in 2DOF Serial Flexible Link and Joint Using Fractional Order PID Controller." Applied Sciences 11, no. 15 (July 21, 2021): 6693. http://dx.doi.org/10.3390/app11156693.

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Robotic manipulators have been widely used in industries, mainly to move tools into different specific positions. Thus, it has become necessary to have accurate knowledge about the tool position using forward kinematics after accessing the angular locations of limbs. This paper presents a simulation study in which an encoder attached to the limbs gathers information about the angular positions. The measured angles are applied to the Kalman Filter (KF) and its variants for state estimation. This work focuses on the use of fractional order controllers with a Two Degree of Freedom Serial Flexible Links (2DSFL) and Two Degree of Freedom Serial Flexible Joint (2DSFJ) and undertakes simulations with noise and a square wave as input. The fractional order controllers fit better with the system properties than integer order controllers. The KF and its variants use an unknown and assumed process and measurement noise matrices to predict the actual data. An optimisation problem is proposed to achieve reasonable estimations with the updated covariance matrices.

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Goudarzi, Pejman, Mehdi Hosseinpour, Roham Goudarzi, and Jaime Lloret. "Holistic Utility Satisfaction in Cloud Data CentreNetwork Using Reinforcement Learning." Future Internet 14, no. 12 (December 8, 2022): 368. http://dx.doi.org/10.3390/fi14120368.

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Cloud computing leads to efficient resource allocation for network users. In order to achieve efficient allocation, many research activities have been conducted so far. Some researchers focus on classical optimisation theory techniques (such as multi-objective optimisation, evolutionary optimisation, game theory, etc.) to satisfy network providers and network users’ service-level agreement (SLA) requirements. Normally, in a cloud data centre network (CDCN), it is difficult to jointly satisfy both the cloud provider and cloud customer’ utilities, and this leads to complex combinatorial problems, which are usually NP-hard. Recently, machine learning and artificial intelligence techniques have received much attention from the networking community because of their capability to solve complicated networking problems. In the current work, at first, the holistic utility satisfaction for the cloud data centre provider and customers is formulated as a reinforcement learning (RL) problem with a specific reward function, which is a convex summation of users’ utility functions and cloud provider’s utility. The user utility functions are modelled as a function of cloud virtualised resources (such as storage, CPU, RAM), connection bandwidth, and also, the network-based expected packet loss and round-trip time factors associated with the cloud users. The cloud provider utility function is modelled as a function of resource prices and energy dissipation costs. Afterwards, a Q-learning implementation of the mentioned RL algorithm is introduced, which is able to converge to the optimal solution in an online and fast manner. The simulation results exhibit the enhanced convergence speed and computational complexity properties of the proposed method in comparison with similar approaches from the joint cloud customer/provider utility satisfaction perspective. To evaluate the scalability property of the proposed method, the results are also repeated for different cloud user population scenarios (small, medium, and large).

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Guo, Shaocui, Xiangrong Tong, and Xu Yang. "Shell Analysis and Optimisation of a Pure Electric Vehicle Power Train Based on Multiple Software." World Electric Vehicle Journal 9, no. 4 (December 5, 2018): 49. http://dx.doi.org/10.3390/wevj9040049.

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Motor end cover mounting fracture is a problem recently encountered by novel pure electric vehicles. Regarding the study of the traditional vehicle engine mount bracket and on the basis of the methods of design and optimisation available, we have analysed and optimised the pure electric vehicle end cover mount system. Multi-body dynamic software and finite element software have been combined. First, we highlight the motor end cover mount bracket fracture engineering problems, analyse the factors that may produce fracture, and propose solutions. By using CATIA software to establish a 3D model of the power train mount system, we imported it into ADAMS multi-body dynamic software, conducted 26 condition analysis, obtained five ultimate load conditions, and laid the foundations for subsequent analysis. Next, a mount and shell system was established by the ANSYS finite element method, and modal, strength, and fatigue analyses were performed on the end cover mount. We found that the reason for fracture lies in the intensity of the end cover mount joint, which leads to the safety factor too small and the fatigue life not being up to standard. The main goal was to increase the strength of the cover mount junction, stiffness, safety coefficient, and fatigue life. With this aim, a topology optimisation was conducted to improve the motor end cover. A 3D prototype was designed accordingly. Finally, stiffness, strength, modal, and fatigue were simulated. Our simulation results were as follows. The motor end cover suspension stiffness increases by 20%, the modal frequency increases by 2.3%, the quality increases by 3%, the biggest deformation decreases by 52%, the maximum stress decreases by 28%, the minimum safety factor increases by 40%, and life expectancy increases 50-fold. The results from sample and vehicle tests highlight that the component fracture problem has been successfully solved and the fatigue life dramatically improved.

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George-Williams, Hindolo, Geng Feng, Frank PA Coolen, Michael Beer, and Edoardo Patelli. "Extending the survival signature paradigm to complex systems with non-repairable dependent failures." Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability 233, no. 4 (November 2, 2018): 505–19. http://dx.doi.org/10.1177/1748006x18808085.

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Dependent failures impose severe consequences on a complex system’s reliability and overall performance, and a realistic assessment, therefore, requires an adequate consideration of these failures. System survival signature opens up a new and efficient way to compute a system’s reliability, given its ability to segregate the structural from the probabilistic attributes of the system. Consequently, it outperforms the well-known system reliability evaluation techniques, when solicited for problems like maintenance optimisation, requiring repetitive system evaluations. The survival signature, however, is premised on the statistical independence between component failure times and, more generally, on the theory of weak exchangeability, for dependent component failures. The assumption of independence is flawed for most realistic engineering systems while the latter entails the painstaking and sometimes impossible task of deriving the joint survival function of the system components. This article, therefore, proposes a novel, generally applicable, and efficient Monte Carlo Simulation approach that allows the survival signature to be intuitively used for the reliability evaluation of systems susceptible to induced failures. Multiple component failure modes, as well, are considered, and sensitivities are analysed to identify the most critical common-cause group to the survivability of the system. Examples demonstrate the superiority of the approach.

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Li, Yufeng, Jingbin Li, Wenhao Zhou, Qingwang Yao, Jing Nie, and Xiaochen Qi. "Robot Path Planning Navigation for Dense Planting Red Jujube Orchards Based on the Joint Improved A* and DWA Algorithms under Laser SLAM." Agriculture 12, no. 9 (September 12, 2022): 1445. http://dx.doi.org/10.3390/agriculture12091445.

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High precision navigation along specific paths is required for plant protection operations in dwarf and densely planted jujube orchards in southern Xinjiang. This study proposes a robotic path planning and navigation method for dense planting of red jujube orchards based on the improved A* and dynamic window approach (DWA) algorithms using Laser Radar to build maps. First, kinematic and physical robot simulation models are established; a map of the densely planted jujube orchard is constructed using Laser Radar. The robot’s position on the constructed map is described using an adaptive Monte Carlo positioning algorithm. Second, a combination of the improved A* and DWA algorithms is used to implement global and real-time local path planning; an evaluation function is used for path optimisation. The proposed path planning algorithm can accurately determine the robot’s navigation paths, with the average error U, average linear path displacement error, and L-shaped navigation being 2.69, 2.47, and 2.68 cm, respectively. A comparison experiment is set up in the specific path navigation section. The experimental results show that the improved fusion algorithm reduces the average navigation positioning deviation by 0.91cm and 0.54 cm when navigating L and U-shaped specific paths. The improved fusion algorithm is superior to the traditional fusion algorithm in navigation accuracy and navigation stability. It can improve the navigation accuracy of the dense planting jujube garden and provide a reference method for the navigation of the plant protection operation in the densely planted jujube orchards.

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Heinrich, Dieter, Antonie J. van den Bogert, and Werner Nachbauer. "Peak ACL force during jump landing in downhill skiing is less sensitive to landing height than landing position." British Journal of Sports Medicine 52, no. 17 (June 28, 2018): 1086–90. http://dx.doi.org/10.1136/bjsports-2017-098964.

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BackgroundCompetitive skiers face a high risk of sustaining an ACL injury during jump landing in downhill skiing. There is a lack of knowledge on how landing height affects this risk.ObjectivesTo evaluate the effect of varied landing height on peak ACL force during jump landing and to compare the effect of the landing height with the effect of the landing position varied by the trunk lean of the skier.MethodsA 25-degree-of-freedom sagittal plane musculoskeletal model of an alpine skier, accompanied by a dynamic optimisation framework, was used to simulate jump landing manoeuvres in downhill skiing. First, a reference simulation was computed tracking experimental data of competitive downhill skier performing a jump landing manoeuvre. Second, sensitivity studies were performed computing 441 landing manoeuvres with perturbed landing height and trunk lean of the skier, and the corresponding effects on peak ACL force were determined.ResultsThe sensitivity studies revealed that peak ACL force increased with jump height and backward lean of the skier as expected. However, peak ACL was about eight times more sensitive to the trunk lean of the skier compared with landing height. The decreased sensitivity of the landing height was based on the lower effects on the knee muscle forces and the shear component of the knee joint reaction force.ConclusionPreventive measures are suggested to focus primarily on avoiding trunk backward lean of the skier, and consequently on proper jump preparation and technique, and secondarily on strategies to reduce landing height during jumps.

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Barrachin, Marc. "Corium Experimental Thermodynamics: A Review and Some Perspectives." Thermo 1, no. 2 (August 11, 2021): 179–204. http://dx.doi.org/10.3390/thermo1020013.

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More than 30 years ago a specialist meeting was held at Joint Research Center Ispra (Italy) from 15 to 17 January 1990 to review the current understanding of chemistry during severe accidents in light water reactors (LWR). Let us consider that, at the end of the 1980s, thermodynamics introduced in the severe accident codes was really poor. Only some equilibrium constants for a few simple reactions between stoichiometric compounds were used as well as some simple correlations giving estimates of solidus and liquidus temperatures. In the same time, the CALPHAD method was developed and was full of promise to approximate the thermodynamic properties of a complex thermochemical system by the way of a critical assessment of experimental data, a definition of a simple physical model and an optimisation procedure to define the values of the model parameters. It was evident that a nuclear thermodynamic database had to be developed with that new technique to obtain quite rapidly prominent progress in the knowledge of thermochemistry in the severe accident research area. Discussions focused on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. The most pressing need for improved chemical models is identified with condensed phase mixtures to model the corium progression. This paper reviews more than 30 years of experimental data production in the field of corium thermodynamics. This work has been conducted through multiple international programs (EURATOM, ISTC, OECD) as well as through more specific studies conducted at the national scale. This research has been capitalised in specific databases such as NUCLEA and TAF-ID, databases developed at IRSN and at CEA, respectively, and are now used in degradation models of the severe accident simulation codes. This research is presented in this paper. In the conclusion, we outline the research perspectives that need to be considered in order to address today’s and tomorrow’s issues.

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Trivedi, Rajesh, Shripad Biniwale, and Adil Jabur. "iPOS–an integrated production operation solution for Longtom Field." APPEA Journal 51, no. 1 (2011): 259. http://dx.doi.org/10.1071/aj10018.

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With a vision of innovation, integrity and agility, Nexus Energy began first production of Longtom field in October 2009. The Longtom gas field is located in the Gippsland Basin, offshore Victoria where the produced gas is transported to Santos’ Patricia Baleen gas processing plant. All production data is acquired by Santos with the supervisory control and data acquisition (SCADA) system. The challenge for Nexus Energy was to monitor the field remotely in the absence of a data historian and to support the operational people proactively. Data acquisition from Santos, validation, and storage in a secured centralised repository were therefore key tasks. A system was needed that would not only track accurate production volumes to meet the daily contractual quantity (DCQ) production targets but that would also be aligned with Nexus’s vision for asset optimisation. We describe how real-time data is acquired, validated, and stored automatically in the absence of a data historian for Longtom field, and how the deployed system provides a framework for an integrated Production Operation System (iPOS). The solution uses an integrated methodology that allows effective monitoring of real-time data trends to anticipate and prevent potential well and equipment problems, thus assisting in meeting DCQ targets and providing effective analysis techniques for decision making. Based on full workflow automation, the system is deployed for acquisition, allocation, reporting and analysis. This has increased accuracy, accountability and timely availability of quality data, which has helped Nexus improve productivity. The comprehensive reporting tool provides access to operational and production reports via email for managers, output reports in various formats for joint venture partners, and nontechnical users without direct access to the core application. A powerful surveillance tool, integrated with the operational database, provides alarms and notifications on operation issues, which helps engineers make proactive operational decisions. The framework allows a streamlined data flow for dynamic updates of well and simulation models, improving process integration and reducing the runtime cycle.

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Ribeiro, M. A., J. L. Silveira, and R. Y. Qassim. "Joint optimisation of maintenance and buffer size in a manufacturing system." European Journal of Operational Research 176, no. 1 (January 2007): 405–13. http://dx.doi.org/10.1016/j.ejor.2005.08.007.

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Balamurugan, K., A. P. Abhilash, P. Sathiya, and A. Naveen Sait. "Artificial neural network simulation and particle swarm optimisation of friction welding parameters of 904L superaustenitic stainless steel." Multidiscipline Modeling in Materials and Structures 10, no. 2 (August 5, 2014): 250–64. http://dx.doi.org/10.1108/mmms-07-2013-0050.

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Purpose – Friction welding (FW) is a solid state joining process. Super austenitic stainless steel is the preferable material for high corrosion resistance requirements. These steels are relatively cheaper than austenitic stainless steel and it is expensive than nickel base super alloys for such applications. The purpose of this paper is to deal with the optimization of the FW parameters of super austenitic stainless steel using artificial neural network (ANN) simulation and particle swarm optimization (PSO). Design/methodology/approach – The FW experiments were conducted based on Taguchi L-18 orthogonal array. In FW, rotational speed, friction pressure, upsetting pressure and burn-off length are the important parameters which determine the strength of the weld joints. The FW trials were carried out on a FW machine and the welding time was recorded for each welding trial from the computerized control unit of the welding machine. The left partially deformed zone (L.PDZ) and right partially deformed zone (R.PDZ) were identified from the macrostructure and their values are considered for the output variables. The tensile test was carried out, and the yield strength and tensile strength of the joints were determined and their fracture surfaces were analyzed through scanning electron microscope (SEM). Findings – The tensile test was carried out, and the yield strength and tensile strength of the joints were determined and their fracture surfaces were analyzed through SEM. An ANN was designed to predict the weld time, L.PDZ, R.PDZ and tensile strength of the joints accurately with respect to the corresponding input parameters. Finally, the FW parameters were optimized using PSO technique. Research limitations/implications – There is no limitations, difficult weld by fusion welding process material can easily weld by FW process. Originality/value – The research work described in the paper is original.

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Patel, G. C. Manjunath, S. Basavarajappa, Irappa Sogalad, and R. Hanumantharaya. "Modelling and optimisation of adhesive bonded joint strength of composites for aerospace applications." International Journal of Computational Materials Science and Surface Engineering 8, no. 3/4 (2019): 167. http://dx.doi.org/10.1504/ijcmsse.2019.10026430.

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Hanumantharaya, R., Irappa Sogalad, S. Basavarajappa, and G. C. Manjunath Patel. "Modelling and optimisation of adhesive bonded joint strength of composites for aerospace applications." International Journal of Computational Materials Science and Surface Engineering 8, no. 3/4 (2019): 167. http://dx.doi.org/10.1504/ijcmsse.2019.104694.

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Salmasnia, Ali, Behnam Abdzadeh, and Aram Rahimi. "Joint optimisation of double warning T2-Hotelling chart and maintenance policy with multiple assignable causes." Journal of Statistical Computation and Simulation 90, no. 3 (December 2, 2019): 465–88. http://dx.doi.org/10.1080/00949655.2019.1688327.

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Jinha, A., R. Ait-Haddou, P. Binding, and W. Herzog. "Antagonistic activity of one-joint muscles in three-dimensions using non-linear optimisation." Mathematical Biosciences 202, no. 1 (July 2006): 57–70. http://dx.doi.org/10.1016/j.mbs.2006.03.018.

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Van Branteghem, Arnaud, Jan Victor, Patrick De Baets, and Matthias Verstraete. "A methodology to develop a patient-specific 3D musculoskeletal model based on MRI, ground reaction forces and motion capture data." International Journal Sustainable Construction & Design 6, no. 2 (July 7, 2015): 5. http://dx.doi.org/10.21825/scad.v6i2.1126.

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The well-documented dissatisfaction of patients with the results of their total knee replacement surgery has been the incentive for deeper research into the optimisation of knee prostheses. One way to optimise total knee replacements is to develop patient-specific 3D musculoskeletal models, enabling a better understanding of the kinematics and kinetics affecting the lower limbs of the patient. This paper suggests a particular methodology to build such personalised models, by implementing data of additional measurement systems. MRI scanning ensures a morphological match between the model and the patient. Additionally, ground reaction force measurements coupled with motion capture provide the kinematic input. A squat test was performed to illustrate the usefulness of the data obtained through the force plates. The combination of this data into the 3D models allows for a more precise calculation and simulation of knee joints. This will ultimately improve the quality of prosthesis testing in a knee-rig setup by providing more accurate boundary conditions.

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Nanekar, P. P., N. Jothilakshmi, and T. Jayakumar. "Simulation studies for optimisation of phased array parameters for examination of roll-joints in pressurised heavy water reactor coolant channels." Insight - Non-Destructive Testing and Condition Monitoring 55, no. 6 (June 1, 2013): 316–22. http://dx.doi.org/10.1784/insi.2012.55.6.316.

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Eidukynas, Rimantas, and Valdas Barauskas. "ANALYSIS OF CONTACT PROBLEMS IN ELASTIC—PLASTIC METAL SEALS/TAMPRIŲJŲ METALINIŲ SANDARIKLIŲ KONTAKTINĖS SĄVEIKOS TYRIMAS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 3, no. 10 (June 30, 1997): 37–42. http://dx.doi.org/10.3846/13921525.1997.10531682.

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One of the most important problems in the design of seal joints is the optimisation of their shape and the material properties. This paper presents the results of the numerical simulation of conical and cantilever seal joints contact problems by using the finite element system ANSYS 5.0A. The temperature and friction have been taken into account. The sealing principle of conical seals, which are usually used as flange joints in networks of pipes, is based on large plastic deformations of seal edges and maintaining the highly elastic property of the whole construction of the seal. Fig 1 presents the scheme of the conical seal used as a base for numerical simulations. The relation between the contact force and displacement in conical seals with various material hardening shows that the contact force is not proportional to the displacement. The latter statement is demonstrated by Fig 2, presenting the results of the numerical simulations, where the curves 1, 2, 3 correspond to the following numerical values of material properties curve 1- E = 2,1.105 MPa, σy = 280 MPa, Eκ1 = 7000 MPa (ε ≤ 0,0125), E&kappa2 = 2500 MPa (0,0125 < ε ≤ 0,0125), Eκ3 = 600 MPa (0,1 < ε ≤ 0,3), Eκ4 = 1000 MPa (ε > 0,3), curve 2—E=2,1.105 MPa, σy = 200 MPa, Eκ = 5.103 MPa; curve 3—E = 2,1.105 MPa, σy = 500 MPa, Eκ = 3.103 MPa. Under displacement 0,7—1,3 mm, the cone seal usually loses stability by exhibiting the second form of instability. Such a sealing joint is not suitable for the practical application as it is not hermetic. Fig 3 shows the deformed shape and contours of the equivalent plastic strains of the above-mentioned conical seal (RAD1=0,153 m, RAD2=0,159 m, h=0,001 m, A=0,0007m, α = 60°, β=0°, ϕ = 10°, γ = 45°, E = 2,1.105 MPa, σy=280 MPa, Eκ1 =7000 MPa (ε ≤ 0,0125), Eκ2 =2500 MPa (0,0125 < ε ≤ 0,0125), Eκ3 = 1600 MPa (0,1 < ε ≤ 0,3), Eκ4 = 1000 MPa (ε > 0,3), ν = 0,3) in one of the loading steps of the solution process. Numerous numerical simulations have shown that the second form of instability is caused by unfavourable loading and boundary conditions for the first instability form. Such numeric results correspond exactly to the experiments. Under high pressure of the working medium (over 40 MPa), such seals collapse by exhibiting the first form of instability. The contact force increases only by 10%, and the collapse occurs when the seal is loaded more than 1,4 mm. V—and λ—form (cantilever) seals may recover from static and 0,1—0,4 mm dynamic displacements due to their high elasticity. Usually such seals possess soft metallic or polymeric coats. The process of the seal deformation is very complex because the contact surface slides and rolls upon the basic surface. In this paper the problem has been solved be using the submodelling techniques of ANSYS. The submodelling involves analysing a coarse model and by subsequently creating the finely meshed “submodel” of the region of interest. The coarse model displacements are applied as constraints on the cut boundary of submodel. In this problem, we will use the region of the whole cantilever seal as the coarse model. The region of interest is the contact zone, so we create the submodel of this region. Due to symmetry, only half a seal needs to be modelled (Fig 4), where RADX = 3 mm,S1 = 5 mm, H1 = 1,7 mm, H2 = 0,5 mm,S2 = 0,5 mm,3 = 2,8 mm, S3=5,5 mm, RAD1 = RAD2 = RAD3 = 1 mm, RADY = 4mm, RADC=30 mm, DD=0,1 mm, δ=0,12 mm, E= 2,1.105 MPa, ν = 0,3. After numerous numerical simulations, the base relations were defined. The maximum stress intensity dependence against the parameters of the arms of the cantilever spring seal elastic zone (Fig 6); ratio of relative seal radius against maximal stress intensity σI, pressure force F and contact pressure q1 (Fig 7). The analysis enabled to obtain the optimised construction of the seal. The elastic-plastic deformation analysis of the coating has been performed. When the loads are small, the stress and strain contours are characteristic of classic Hertzian [1] contact theory. With higher loads, the picture changes significantly. After increasing the contact area width, the plastic zone grows and develops through to the boundaries of the interacting region. By summarising the simulation results were obtained: the relations between the contact width, the approach of the contact surfaces δ, relative contact force Fk and ratio q/σy, when coating thickness is 0,14 mm and radius of the indenter 0,5 mm. The relation q/σy in this case is constant, approximately equal to 16. With the increase of the indenter radius, the ratio q/σy is not constant and increases with an increase of the contact force. The numerical simulations of various seals allow to arrive to the following conclusions: For cone seals the geometric instability (usually in the second form) is exhibited even at computatively small loads. When the loading exceeds 1,2 mm, the elastic structure may acquire an unaxisymmetric form. In the usage of such seals, the following points should be taken into account: it is necessary to match the materials properly. Best suitable materials have higher yield point and higher stiffness hardening; try to keep axisymmetric form of a seal even under the collapse. For this reason it is necessary to keep high requirements; good results are obtained by covering the seals with soft coatings, thus reducing the force. In such way only the coating is subjected to the plastic deformation, while the whole structure remains elastic. Cantilever seals have good elastic properties and do not loose stability. After summarising the numerical simulations results, the suggestions for the rational geometric shape of the cantilever seal have been made. In the design of coated seals it is necessary to take into account that the equivalent plastic strains in the coat layers close to the indenter increase with increasing contact force, decreasing the indenter radius and the coat thickness

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Wen-Peng, Tian, Dou Jian-Ming, and Xu Xin-Xin. "Modelling and characteristics of hybrid coupling hydro-pneumatic suspension for a seven-axle vehicle." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, December 29, 2020, 095440702098321. http://dx.doi.org/10.1177/0954407020983212.

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A hybrid coupling scheme of parallel connection and contralateral cross-linking was proposed based on the characteristics of high centroid position and low rollover threshold on hydro-pneumatic suspension (HPS) for a seven-axle elevated platform vehicle. A dynamic model with 20 DOFs which can comprehensively reflect vehicle coupling vibration including vertical-lateral-longitudinal-transverse and the joint simulation model of Simulink and AMESim were established based on the structural characteristics of the vehicle. Furthermore, the random road surface model linking the wheels was constructed by filter shaping white noise. Based on the model of hybrid coupling HPS, the study of joint simulation and test on the whole vehicle were conducted, and improved ant colony algorithm (IACA) was applied to the multi-objective optimisation study of HPS parameter matching. The comparison between simulation and test data shows that the weighted acceleration PSD curve is in good agreement, and the relative error of weighted acceleration RMS is small, which indicated that the theoretical model was accurate. The results of simulation and testing show that the optimal parameter matching scheme output by IACA can improve vehicle ride comfort and stability to a significant extent.

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Xiao, Zongxin, Minghui Hu, Chunyun Fu, and Datong Qin. "Model predictive trajectory tracking control of unmanned vehicles based on radial basis function neural network optimisation." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, February 23, 2022, 095440702210801. http://dx.doi.org/10.1177/09544070221080158.

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To improve the accuracy of tracking unmanned vehicles on known trajectories, two optimised model predictive control (MPC) trajectory tracking control systems are designed based on the adaptive compensation and robust control of a radial basis function (RBF) neural network. Based on the traditional MPC trajectory tracking controller and the local approximation characteristics of the RBF neural network, the proposed RBF compensation–MPC control system is designed to compensate for the inaccuracy in the MPC prediction model arising from modelling errors. The results show that this method can achieve a root mean square error of less than 0.3703 m for the lateral position. Subsequently, to suppress the error generated by the RBF neural network and reduce the degree of vehicle sideslip, the error is considered to be external interference, and the anti-interference characteristic of the RBF robust control is incorporated into the RBF robust-MPC control system. Following the re-optimisation of the RBF robust control, the root mean square error of the lateral position is set within 0.2352 m. The results of a MATLAB/Carsim joint simulation show that using the RBF robust control can improve the tracking accuracy of the traditional MPC controller compared with RBF compensation control, while simultaneously improving the driving stability of the vehicle.

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Xing, Xinjie, Dongping Song, Chengfeng Qiu, Paul R. Drake, and Yuanzhu Zhan. "Joint tank container demurrage policy and flow optimisation using a Progressive Hedging Algorithm with Expanded Time-Space Network." European Journal of Operational Research, September 2022. http://dx.doi.org/10.1016/j.ejor.2022.08.044.

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Journal articles on the topic 'Joint simulation-optimisation'

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