Relevant bibliographies by topics / Methodology for evaluating the fatigue life

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Methodology for evaluating the fatigue life'

Author: Grafiati
Published: 4 June 2021
Last updated: 9 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Methodology for evaluating the fatigue life.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Methodology for evaluating the fatigue life"

1

Woo, Chang Su, Wan Doo Kim, Jae Do Kwon, and Wan Soo Kim. "Fatigue Life Prediction of the Vulcanized Natural Rubber." Key Engineering Materials 297-300 (November 2005): 16–21. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.16.

Full text
Abstract:
Fatigue lifetime prediction methodology of the vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue test. Finite element analysis of 3D dumbbell specimen of natural rubber was performed based on a hyper-elastic material model determined from the tension, compression and shear tests. Stroke controlled fatigue tests were conducted using fatigue specimens at different levels of mean strain. The Green-Lagrange strain at the critical location determined from the FEM was used for evaluating the fatigue damaged parameter of the natural rubber. It was shown that the maximum Green-Lagrange strain was proper damage parameter, taking the mean strain effects into account. Fatigue lives of the natural rubber are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the natural rubber agreed fairly well the experimental fatigue lives a factor of two.
APA, Harvard, Vancouver, ISO, and other styles
2

Woo, Chang Su, Wan Doo Kim, and Jae Do Kwon. "Fatigue Life Evaluation of Rubber Components for Automobile Vehicles." Key Engineering Materials 324-325 (November 2006): 181–84. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.181.

Full text
Abstract:
The interest of the fatigue life for rubber components was increasing according to the extension of warranty period of the automotive components. In this study, the fatigue lifetime prediction methodology of the vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue tests. Finite element analysis of 3D dumbbell specimen and rubber component was performed based on a hyper-elastic material model determined from the mechanical tests. The Green-Lagrange strain at the critical location determined from the finite element analysis was used for evaluating the fatigue damage parameter of the natural rubber. Fatigue tests were performed using the 3D dumbbell specimens and rubber component with different levels of maximum strain and various load. Fatigue life curves can be effectively represented by a following single function using the maximum Green-Lagrange strain. Fatigue lives of the natural rubber are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the rubber component for automobile vehicle agreed fairly with the experimental fatigue lives.
APA, Harvard, Vancouver, ISO, and other styles
3

de Sousa, José Renato M., Fernando J. M. de Sousa, Marcos Q. de Siqueira, Luís V. S. Sagrilo, and Carlos Alberto D. de Lemos. "A Theoretical Approach to Predict the Fatigue Life of Flexible Pipes." Journal of Applied Mathematics 2012 (2012): 1–29. http://dx.doi.org/10.1155/2012/983819.

Full text
Abstract:
This paper focuses on a theoretical approach to access the fatigue life of flexible pipes. This methodology employs functions that convert forces and moments obtained in time-domain global analyses into stresses in their tensile armors. The stresses are then processed by well-known cycle counting methods, andS-Ncurves are used to evaluate the fatigue damage at several points in the pipe’s cross-section. Finally, Palmgren-Miner linear damage hypothesis is assumed in order to calculate the accumulated fatigue damage. A study on the fatigue life of a flexible pipe employing this methodology is presented. The main points addressed in the study are the influence of friction between layers, the effect of the annulus conditions, the importance of evaluating the fatigue life in various points of the pipe’s cross-section, and the effect of mean stresses. The results obtained suggest that the friction between layers and the annulus conditions strongly influences the fatigue life of flexible pipes. Moreover, mean stress effects are also significant, and at least half of the wires in each analyzed section of the pipe must be considered in a typical fatigue analysis.
APA, Harvard, Vancouver, ISO, and other styles
4

Guo, Min, Bo Zhu, Jianli Liu, and Weidong Gao. "Optimizing parameters of warp fatigue life tester by response surface methodology." Journal of Engineered Fibers and Fabrics 14 (January 2019): 155892501989380. http://dx.doi.org/10.1177/1558925019893808.

Full text
Abstract:
The aim of this article was to provide an effective measurement method of the warp dynamic load capacity based on a warp fatigue life tester for sized yarns. Five parameters which affected the fatigue life of warp, respectively, namely, load frequency, warp speed, pre-tension weight, heald frame stroke, and static tension of the warp fatigue life tester, were studied. First, the influences of the five parameters on warp fatigue life were analyzed through single-factor experiments, and then, the Box–Behnken design based on the response surface methodology was adopted to optimize warp fatigue life tester parameters. The results showed that the optimum parameter conditions of the warp fatigue life tester for warp fatigue life were as follows: when heald frame stroke at 77.16 mm, load frequency of 205.49 times/min, and static tension as 6.96 cN, the optimal warp fatigue life was 1394.05 times. The theoretical and experimental values were in reasonable agreement, and the relative error was less than 1%. Verification and repeated trial results showed that the optimal parameters had good reproducibility, and the warp fatigue life tester with the optimal parameters provided an effective and reliable evaluation to the warp frictional, stretching, and buckling effects.
APA, Harvard, Vancouver, ISO, and other styles
5

Pettinà, Michele, Bahram Farahmand, Filippo Berto, and Frank Abdi. "Virtual Testing for Fracture Toughness, Fatigue Crack Growth and Fatigue Life Data Estimation of Metallic Components." Key Engineering Materials 577-578 (September 2013): 177–80. http://dx.doi.org/10.4028/www.scientific.net/kem.577-578.177.

Full text
Abstract:
Evaluating fracture and fatigue life properties of structural components involves tests that are costly and time consuming. To estimate total life of engineering parts, high cycle fatigue data (S-N) for the material under study is needed. In many cases the S-N data is not available to the analyst and both the time and budget required for testing prevent engineers to meet the deadline imposed on the program. An analytical combined Progressive Damage and Fracture Mechanics based approach is proposed that estimates the S-N data for components that have stress concentrations. The proposed methodology starts from a full engineering tensile stress-strain curve of the material under study and ends up with the estimation of fracture toughness, fatigue crack growth and fatigue S-N curves.
APA, Harvard, Vancouver, ISO, and other styles
6

Woo, Chang Su, Wan Doo Kim, and Jae Do Kwon. "A Study on the Fatigue Life Prediction and Evaluation of the Natural Rubber Components for Automobile Vehicles." Key Engineering Materials 326-328 (December 2006): 589–92. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.589.

Full text
Abstract:
The fatigue analysis and lifetime evaluation are very important in design procedure to assure the safety and reliability of the rubber components. The interest of the fatigue life of rubber components such as the engine mount is increasing according to the extension of warranty period of the automotive components. In this study, the fatigue lifetime prediction methodology of the vulcanized natural rubber was proposed by incorporating the finite element analysis and fatigue damage parameter determined from fatigue tests. Finite element analysis of 3D dumbbell specimen of natural rubber was performed based on a hyper-elastic material model determined from the tension, compression and shear tests. The Green-Lagrange strain at the critical location determined from the finite element analysis was used for evaluating the fatigue damage parameter of the natural rubber. Fatigue tests were performed using the 3D dumbbell specimens with different levels of maximum strain and various load. The basic mechanical properties test and the fatigue test of rubber specimens under the normal and elevated temperature were conducted. Fatigue life curves can be effectively represented by a following single function using the maximum Green-Lagrange strain. Fatigue lives of the natural rubber are predicted by using the fatigue damage parameters at the critical location. Predicted fatigue lives of the engine mount agreed fairly with the experimental fatigue lives a factor of two.
APA, Harvard, Vancouver, ISO, and other styles
7

Nahm, Seung Hoon, Chang Min Suh, Min Woo Jung, Jong Yup Kim, and Chang Hwan Yang. "Application of Damage Tolerance Approach for Turbine Disk Life Extension." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1916–21. http://dx.doi.org/10.1142/s0217979203019873.

Full text
Abstract:
For gas turbine engines, the safe life methodology has historically been used for fatigue life management of failure critical engine components. The safe retirement limit is necessarily determined by a conservative life evaluation procedure, thereby many components which have a long residual life are discarded. The objective of this study is to introduce the damage tolerant design concept into the life management for aircraft engine component instead of conservative fatigue life methodology which has been used for both design and maintenance. The residual lives of turbine disk component under various temperatures and conditions using creep-fatigue crack initiation and growth data were estimated. As the result of analysis, it was confirmed that retirement for cause concept was applicable to the evaluation of residual life of retired turbine disk which had been designed based on the conventional fatigue life methodology.
APA, Harvard, Vancouver, ISO, and other styles
8

Yeom, Jong Taek, Chong Soo Lee, Jeoung Han Kim, Dong Geun Lee, and Nho Kwang Park. "Continuum Damage Model of Creep-Fatigue Interaction in Ni-Base Superalloy." Key Engineering Materials 340-341 (June 2007): 235–40. http://dx.doi.org/10.4028/www.scientific.net/kem.340-341.235.

Full text
Abstract:
A methodology for evaluating and predicting component lives in creep-fatigue interaction region was investigated for Waspaloy. A unified viscoplasticity constitutive equation including multi-back stresses was used to describe cyclic material behaviors. Also, a continuum damage model coupling with the creep-fatigue damage rules was established based on the analysis of creep and low cycle fatigue behavior. Multi-axial fatigue and creep equivalent stress concepts were employed to predict three dimensional component lives. Notched cyclic tests under various stress conditions in the creep-fatigue interaction region were carried out to validate the life prediction methodology with FEM simulation based on the continuum damage model. The comparison of experimental data and prediction results indicates that the continuum damage model is a powerful approach for the prediction of component lives.
APA, Harvard, Vancouver, ISO, and other styles
9

Luo, R. K., B. L. Gabbitas, and B. V. Brickle. "Fatigue Life Evaluation of a Railway Vehicle Bogie Using an Integrated Dynamic Simulation." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 208, no. 2 (July 1994): 123–32. http://dx.doi.org/10.1243/pime_proc_1994_208_242_02.

Full text
Abstract:
An integrated design methodology has been developed for the fatigue life evaluation of railway vehicle bogies. In principle, there are five parts in the procedure: specification and measurement of track irregularities; modelling a railway vehicle and description of rail-wheel profiles; obtaining the railway vehicle suspension load histories; dynamic analysis and stress evaluation of the bogie frame; fatigue life evaluation of the bogie. The whole procedure has been applied to a typical London Underground railway vehicle. The theoretical results have been validated against field test data and fatigue calculations have indicated good agreement with operational data from the actual vehicles. It has been shown that a design methodology for railway vehicle bogies based on the track profiles on which they will run and on their own structural characteristics is possible and can be used at an appropriate stage in the design process.
APA, Harvard, Vancouver, ISO, and other styles
10

Song, Yongsheng, Youliang Ding, Fei Jiang, Zhiwen Wang, Jun Lu, and Huijuan Jia. "Multiaxial Fatigue Assessment for the Hanger Deck Connection of a High-Speed Steel-Truss-Arch Railway Bridge." Applied Sciences 11, no. 3 (January 26, 2021): 1142. http://dx.doi.org/10.3390/app11031142.

Full text
Abstract:
Steel-truss-arch bridges have been applied in high-speed railway bridges due to their excellent dynamic and static structural performance. Under the action of high-speed trains, the steel connections between hangers and decks suffer from repeated stresses, inducing potential fatigue problems or even fatigue failure. In this study, a multiaxial fatigue evaluation method was first created and established based on critical damage-plane methodology, following which the fatigue evaluation procedure was also created and recommended. The methodology was applied to real-life strain data from a high-speed railway bridge from which an assessment of fatigue damage and predicted fatigue life was estimated. The connection between the shortest hanger and deck on the downstream side was selected as the target due to its relatively high stress. A multiscale finite-element model of this bridge was created according to the design profile and monitoring results of traffic flow, where the finite-element model was calibrated and validated by comparing the calculation results with the monitoring data. Influence analysis was then carried out to investigate two factors—i.e., the total traffic flow and compositions of freight trains—having effects on the fatigue life of the steel connection. The results indicate that the applied multiaxial fatigue method is suitable for online fatigue evaluation of actual bridges. In addition, by using the multiaxial fatigue method, the fatigue-damage accumulation rate can be nearly 60 times that obtained by the uniaxial fatigue method. If freighting is taken into consideration, the fatigue damage will increase rapidly, and for the case 10% of proportion traffic as freighting, the actual fatigue life is estimated to be shorter than the design life.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Methodology for evaluating the fatigue life"

1

Leque, Nicholas. "Development of an Experimental Methodology for Evaluation of Gear Contact Fatigue under High-Power and High-Temperature Conditions." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1312897007.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Adámek, Petr. "Kritéria hodnocení únavové životnosti nýtových spojů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232022.

Full text
Abstract:
This thesis describes proposal of a methodology for evaluating fatigue life of riveted joints. The first section summarizes the theory used to evaluate fatigue life, description of the structure of operation load spectra and construction principles for the design joints for optimum durability. The second part of the thesis focuses on the proposal of a methodology enabling analytical solutions in closed form suitable for the initial structural design and also numerical solutions for use in detailed analyzes of the structure. The applicability of the methodology is demonstrated on an example of analysis of a real structural detail and subsequent comparison of the analysis with available test results.
APA, Harvard, Vancouver, ISO, and other styles
3

Abdullah, A. B. M. "Development of a Closed-loop Resonant Fatigue Testing Methodology and Experimental Life Test of Aluminum Alloy." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1289328504.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Narayanaswamy, Nitin. "Adhesive modelling in multi-material structures : Evaluating the strength and fatigue life of adhesive joints." Thesis, Linköpings universitet, Mekanik och hållfasthetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165507.

Full text
Abstract:
Advancements in material science and manufacturing techniques are enabling the use of lightweight metal alloys and polymer composites in several combinations and shapes for producing more efficient and lightweight structures for automotive applications without compromising strength, stiffness and/or durability. When evaluating the strength of the structure, the joints are of importance. For multi-material structures adhesives are often the best type of joints. However, traditional finite element methods using stress criteria cannot accurately predict the failure of these adhesive joints under static loading. In this thesis work a strength and fatigue model, formulated using energy release rate theory, is implemented in a post processing tool. Given a finite element model of an adhesive joint and a list of boundary elements and nodes this tool calculates the energy release rates in mode I and mode II, and if the fracture toughness of the adhesive is known, a prescribed mixed-mode failure index is calculated. To evaluate its predictions joint strength results are correlated to experiments. Specimens with combined shear and normal load forms the underlying experimental setup with change in strain rate and adhesive thickness as varying parameters. Methods for implementing the model for a car body structure with multiple adhesive joints is investigated, the tool proves to be scalable, however, the required finite element setup at the adhesive boundaries may not be present in a car body model and thus further work needs to carried out to accommodate irregularities like non-matching mesh in the car body finite element model. This model may be used for assessing the strength and durability of a car body structure comprising different materials joined together using adhesives.
APA, Harvard, Vancouver, ISO, and other styles
5

Stitt, Alice C. "A physics-based maintenance cost methodology for commercial aircraft engines." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/13134.

Full text
Abstract:
A need has been established in industry and academic publications to link an engine's maintenance costs throughout its operational life to its design as well as its operations and operating conditions. The established correlations between engine operation, design and maintenance costs highlight the value of establishing a satisfactory measure of the relative damage due to different operating conditions (operational severity). The methodology developed in this research enables the exploration of the causal, physics-based relationships underlying the statistical correlations in the public domain and identifies areas for further investigation. This thesis describes a physics-based approach to exploring the interactions, for commercial aircraft, of engine design, operation and through life maintenance costs. Applying the "virtual-workshop" workscoping concept to model engine maintenance throughout the operating life captures the maintenance requirements at each shop visit and the impact of a given shop visit on the timing and requirements for subsequent visits. Comparisons can thus be made between the cost implications of alternative operating regimes, flight profiles and maintenance strategies, taking into account engine design, age, operation and severity. The workscoping model developed operates within a physics-based methodology developed collaboratively within the research group which encompasses engine performance, lifing and operational severity modelling. The tool-set of coupled models used in this research additionally includes the workscoping maintenance cost model developed and implements a simplified 3D turbine blade geometry, new lifing models and an additional lifing mechanism (Thermo-mechanical fatigue (TMF)). Case studies presented model the effects of different outside air temperatures, reduced thrust operations (derate), flight durations and maintenance decisions. The use of operational severity and exhaust gas temperature margin deterioration as physics based cost drivers, while commonly accepted, limit the comparability of the results to other engine-aircraft pairs as the definition of operational severity, its derivation and application vary widely. The use of a single operation severity per mission based on high pressure turbine blade life does not permit the maintenance to vary with the prevalent lifing mechanism type (cyclic/steady state).
APA, Harvard, Vancouver, ISO, and other styles
6

Horas, Cláudio Carlos da Silva. "Integrated Methodology for Fatigue Life Prediction of Existing Metallic Railway Bridges." Doctoral thesis, 2021. https://hdl.handle.net/10216/136063.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Cowell, Jason Michael. "Development of a practical fatigue analysis methodology for life prediction of rotary-wing aircraft components." 2006. http://www.lib.ncsu.edu/theses/available/etd-05142006-205910/unrestricted/etd.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Chiang, Kuen-Shiue, and 蔣坤斈. "Optimal Design of Fatigue Life for Fan-out Wafer Level Package by Using Taguchi Method and Response Surface Methodology." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/uw84hp.

Full text
Abstract:
碩士
國立交通大學
機械工程系所
107
Electronic components tend toward demand such as「light weight、reliability、high component density」.The size of package is gradually reduced,the coefficient of thermal expansion between components are not matched, which result damage of the solder ball or the solder bump structure to be the main cause of product failure. In this paper,Fan-out Wafer Level Package and the Ball Grid Array are numerically analyzed. According to the specifications of the JEDEC, the model is built using ANSYS Static Structure to simulate fatigue life of package solder balls under Test Cycling Temperature. The package material was selected as the of the experimental design Taguchi Method and Response Surface Methodology. The influence of each control factor on package life of the solder ball was applied through the analysis results of two experimenta designs. The results of the study show that change the coefficient of thermal expansion, Young's Module, Poisson's ratio, and glass transition temperature of the Fan-out Wafer Level Package materials. and collocate Taguchi Method and the Response Surface Methodology to achieve a package fatigue life of 9,944 cycles (Cycling) and 11625 cycles (Cycing). The original package fatigue life (7395 cycles) increased by 34.48% and 57.21%, and the two optimization methods have a 23.27 percentage difference, indicating that the reaction surface method has better benefits than the Taguchi method. Since the Ball Grid Array structure is similar to Fan-out Wafer Level Package, then simulation analysis of the ball grid array package is compared with the simulation of the fan-out package, The fatigue life of the solder ball was optimized by the Taguchi method and the response surface method was optimized to be 12538 cycles and 13740 cycles, which was 45.03% and 58.94% higher than the original fatigue life (8645). Although the fan-out package structure is similar to the ball grid array package, the lifetime is lower 1250 cycles. Inferred that the solder ball in the fan-out area facing warpage effect due to high temperature, which causes the life of the solder ball to be greatly reduced, which affects the fatigue life of the whole package. . Both optimization methods improve package reliability and improve the fatigue life of the package solder balls. The results of this study provide a reference for improving package reliability.
APA, Harvard, Vancouver, ISO, and other styles
9

Minhoto, Manuel J. C. "Consideração da temperatura no comportamento à reflexão de fendas dos reforços de pavimentos rodóviários flexíveis." Doctoral thesis, 2007. http://hdl.handle.net/1822/6751.

Full text
Abstract:
Tese de Doutoramento em Engenharia Civil
Os pavimentos rodoviários flexíveis quando expostos às acções do tráfego e das variações de temperatura ficam sujeitos à ocorrência de um conjunto de degradações, das quais se destaca o fendilhamento. Este constitui uma das principais degradações dos pavimentos flexíveis e conduz a estados de ruína associados a situações de desconforto e de redução de segurança para os utentes. Além disso permite a entrada de água para as camadas do pavimento, com a consequente redução da capacidade de suporte, potenciando a ocorrência de outros tipos de degradações. Constitui, assim, uma preocupação das administrações rodoviárias atrasar ou, quando possível, evitar ocorrência de fendilhamento nos pavimentos flexíveis, tendo em vista o seu bom desempenho funcional e estrutural. O reforço de pavimentos constitui uma técnica de conservação estrutural, na qual se baseiam as estratégias de conservação mais utilizadas para benefíciação dos pavimentos, tendo em vista a reposição da sua capacidade estrutural. A maioria das metodologias existentes para dimensionamento de reforços, normalmente não consideram o mecanismo de ruína da propagação das fendas do pavimento existente para as camadas de reforço, e as que consideram, não envolvem o efeito das variações de temperatura associado àquele mecanismo. Efectivamente, a ocorrência de variações de temperatura nos pavimentos conduz ao agravamento do fenómeno da propagação de fendas, levando à ruína prematura dos reforços. Assim, é fundamental, para o dimensionamento do reforço de um pavimento, a consideração das variações de temperatura na avaliação do comportamento dos reforços à reflexão de fendas. Pretende-se com este trabalho estudar a influência das variações de temperatura no comportamento dos reforços à reflexão de fendas, contribuindo para uma melhoria dos métodos de concepção de reforços de pavimentos flexíveis que considerem a propagação de fendas como um dos critérios de mína. O desenvolvimento deste estudo foi baseado na simulação numérica do comportamento dos reforços, considerando a acção conjunta do tráfego e das variações de temperatura, desenvolvendo-se modelos térmicos e mecânicos baseados na metodologia dos elementos finitos.
Road pavements, when exposed to traffic and temperature variations are subjected to a set of degradations on its surface, mainly to pavement cracking. Pavement cracking constitutes one of the main degradation of flexible pavements and it provokes distress states in the pavement which are responsible for the users' discomfort and safety reduction. Moreover, it allows the intrusion of water and the subsequent reduction of the pavement bearing capacity. Thus, on behalf of the road administrations, there is a concern to prevent cracking in flexible pavements or to delay its appearance, in order to present a good functional and structural perfomance. The pavement overlay consists of one structural maintenance technique that is in the base of the more used maintenance strategies of pavements rehabilitation to increase its structural capacity. The majority of the existing overlay design methods do not normally consider the distress mechanism of reflective cracking. On the other hand the ones that consider it do not point at the effect of temperature variations associated to that mechanism. Effectively, the occurrence of temperature variations in pavements leads to the reflective cracking phenomenon aggravation, what implies a premature distress of the overlays. Thus, for the pavement overlay design purposes, it is important to consider the temperature variations in the evaluation of the reflective cracking overlay behavior. With this thesis it is intended to study the influence of temperature variations in the reflective cracking overlay behavior. ln that way, it is intended to contribute, with fhe obtained knowledge to the improvement of the pavement overlays design methods, which consider the reflective cracking as one of distress criteria. The development of this study was based on the numerical simlulation of the overlay behaviour, considering the simultaneous action of traffic and temperature variations. Thermal and mechanical models based on finite element methodology were developed to take into account the traffic and temperature variations in the reflective cracking.
Programa para o Desenvolvimento Educatico para Portugal (PRODEPIII)
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Methodology for evaluating the fatigue life"

1

Fatigue life and crack growth prediction methodology. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

P, Phillips E., Everett R. A, and Langley Research Center, eds. Fatigue life and crack growth prediction methodology. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

P, Phillips E., Swain M. H, and Langley Research Center, eds. Fatigue-life prediction methodology using small-crack theory. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kevin, O'Brien T., Rousseau Carl Q, and United States. National Aeronautics and Space Administration., eds. Fatigue life methodology for tapered composite flexbeam laminates. [Washington, DC: National Aeronautics and Space Administration, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Kevin, O'Brien T., Rousseau Carl Q, and Langley Research Center, eds. Fatigue life methodology for tapered composite flexbeam laminates. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

P, Phillips E., Swain M. H, and Langley Research Center, eds. Fatigue-life prediction methodology using small-crack theory. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Kevin, O'Brien T., Rousseau Carl Q, and Langley Research Center, eds. Fatigue life methodology for tapered composite flexbeam laminates. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

P, Phillips E., Swain M. H, and Langley Research Center, eds. Fatigue-life prediction methodology using small-crack theory. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

P, Phillips E., Swain M. H, and Langley Research Center, eds. Fatigue-life prediction methodology using small-crack theory. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Kevin, O'Brien T., Rousseau Carl Q, and United States. National Aeronautics and Space Administration., eds. Fatigue life methodology for tapered composite flexbeam laminates. [Washington, DC: National Aeronautics and Space Administration, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Methodology for evaluating the fatigue life"

1

Igumnov, Leonid A., Ivan A. Volkov, and Sergey Ye Vlasov. "Evaluating Fatigue Life of Structures Under Thermocyclic Loading." In Multiscale Solid Mechanics, 213–35. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-54928-2_17.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Mostakhdemin, Mohammad, Iraj Sadegh Amiri, and Ardiyansyah Syahrom. "Methodology of Fatigue Life Simulation in Trabecular Bone." In Multi-axial Fatigue of Trabecular Bone with Respect to Normal Walking, 15–35. Singapore: Springer Singapore, 2015. http://dx.doi.org/10.1007/978-981-287-621-8_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kocańda, Stanisław, and Henryk Tomaszek. "Probabilistic Method of Evaluating Fatigue Life of Aircraft Structure Components." In Low Cycle Fatigue and Elasto-Plastic Behaviour of Materials—3, 485–89. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2860-5_78.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Pangborn, Robert N., and Sam Y. Zamrik. "Fatigue Damage Assessment by X-Ray Diffraction and Nondestructive Life Assessment Methodology." In Nondestructive Characterization of Materials IV, 259–68. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4899-0670-0_31.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Xie, Yong Hui, Di Zhang, Zhen Ping Feng, and Bi Sun. "Synthetical Numerical Model for Evaluating Blade Fatigue Life of Liquid Corrosion in Steam Turbine." In Fracture and Damage Mechanics V, 165–68. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-413-8.165.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Ohtani, R., and T. Kitamura. "A Method for Evaluating the Lower Bound of Thermal Fatigue Life in Microelectronic Package Metals." In Fracture of Engineering Materials and Structures, 283–88. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3650-1_40.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hu, B. R., J. Z. Liu, B. Chen, L. F. Wang, and Xue Ren Wu. "Fatigue Behavior and Life Prediction for Argon-Arc Weld Joints Based on Small Crack Methodology." In Fracture and Strength of Solids VI, 157–62. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-989-x.157.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Leturiondo, Urko, Oscar Salgado, Diego Galar, and Madhav Mishra. "Methodology for the Estimation of the Fatigue Life of Rolling Element Bearings in Non-stationary Conditions." In Applied Condition Monitoring, 413–23. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-20463-5_31.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Jing, Song, Zhang Yidu, and Sun Ke. "The Numerical Simulation for Effect of Vibratory Stress Relief on Titanium Alloy Ti-6Al-4V Fatigue Life." In Theory, Methodology, Tools and Applications for Modeling and Simulation of Complex Systems, 530–39. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-2669-0_57.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Sharma, Shashi Kant, and K. P. Marisarla Chaitanya. "Evaluating Toughness as a Parameter to Determine the Fatigue Life of Wollastonite Microfiber Reinforced High Flow Pavement Quality Concrete." In Lecture Notes in Civil Engineering, 145–67. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5235-9_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Methodology for evaluating the fatigue life"

1

Diwakar, Philip, Yuqing Liu, and Matt Jaouhari. "Estimating Fatigue Life of Thermowells in Supercritical Operation." In ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fedsm2018-83426.

Full text
Abstract:
Designing structures resistant to failure due to fluid induced vibration is a challenge. This paper shows a methodology of evaluating the cycles to failure of thermowells placed in a fluid flow through a large pipe in supercritical operation. The ASME PTC guide describes using Finite Element Analysis (FEA) to evaluate these conditions on a case by case basis. One case from several validated cases is presented using measurements available from the field.
APA, Harvard, Vancouver, ISO, and other styles
2

Ouronon Marie Rosalie Beugre, Fábio Comes de Castro, and Edgar Nobuo Mamiya. "EVALUATION OF A FATIGUE LIFE ESTIMATION METHODOLOGY FOR VARIABLE AMPLITUDE LOADING." In 23rd ABCM International Congress of Mechanical Engineering. Rio de Janeiro, Brazil: ABCM Brazilian Society of Mechanical Sciences and Engineering, 2015. http://dx.doi.org/10.20906/cps/cob-2015-0460.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Samaria, Sagar, Bob Zhang, Sudhakar Tallavajhula, and Johyun Kyoung. "Structural Connection Fatigue Evaluation Methodology Using Time Domain Approach." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18229.

Full text
Abstract:
Abstract There is an ever-increasing demand for life extension of existing floating platforms worldwide. To adequately support these life extension projects there is a need to predict fatigue life of floating structures more accurately using a time domain approach. However, structural fatigue damage calculations using time domain response analysis can be very time consuming and challenging. An efficient and effective structural analysis methodology is developed to calculate accumulated fatigue damage for structural connections in a floating offshore platform using a response-based time domain routine. The methodology discussed in this paper can be applied to estimate fatigue life for hull critical connections in floaters such as Spars, TLPs or Semis as well as local structural supports such as mooring foundations and riser foundations. It also provides the option to generate stress histograms that can be utilized for Fracture Mechanics Evaluation (FME) of welds in structural connections. To calculate the accumulated fatigue damage at desired locations on a floating platform, the time domain analysis employs a Stress Intensification Factor (SIF) which correlates global loads with local stresses. In cases where a crack initiation is observed on a structural connection, fracture mechanics is used to evaluate the structural integrity of the weld. The FME requires fatigue stress range histograms as one of the input parameters. The stress ranges and cycles that are calculated and used to compute the fatigue damage using this methodology can be converted to stress range histograms which can then be used in the FME. The standard method to compute fatigue damage for a structural connection is by using an S-N fatigue approach under the assumption of linear cumulative damage (Palmgren-Miner rule). The methodology discussed in this paper uses a rainflow counting algorithm to effectively calculate the stress range and cycles which are then utilized for computing the fatigue damage. This methodology can be applied to green field projects involving a new design or for life of field studies of an existing platform requiring life extensions. It is particularly beneficial for brownfield projects where more accurate re-evaluation of fatigue life is needed. It can also provide Clients with reliable Engineering Criticality Assessments (ECA) and enable them to plan in-service inspections and repair work. As an application, a typical truss connection for a Spar platform is used to evaluate structural fatigue damage and generate the stress range histogram for FME. Also, a comparative study is performed for a typical truss connection fatigue damage result between the traditional approach used and the method discussed in this paper.
APA, Harvard, Vancouver, ISO, and other styles
4

Cravero, Sebastian, Luciano Mantovano, and Hugo Ernst. "Fatigue Life Estimation in Complex Geometries and Loadings." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83555.

Full text
Abstract:
Components with complex geometries and loading conditions frequently serve under cyclic loadings. This situation makes the evaluation of fatigue life in mechanical parts a fundamental issue. Particularly, for notched geometries and loadings involving plasticity, the cyclic stress and strain fields should be determined using finite elements models. The difficulties are increased since the constitutive equations of material under cyclic plasticity employed in the finite element codes is still an active research field and simplifications must be assumed always. In this paper a comprehensive study of strain-life method for fatigue estimation is presented. In addition, the difficulties found to establish a reliable methodology are enumerated.
APA, Harvard, Vancouver, ISO, and other styles
5

Aumuller, John J., Jie Chen, and Vincent A. Carucci. "A Rational Methodology for Determination of Service Life for a Delayed Coker Drum." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45028.

Full text
Abstract:
Delayed unit coker drums operate in a severe service environment that precludes long term reliability due to excessive shell bulging and cracking of shell joint and shell to skirt welds. Thermal fatigue is recognized as the leading damage mechanism and past work has provided an idealized description of the thermo-mechanical mechanism via local hot and cold spot formation to quantify a lower bound life estimate for shell weld failure. The present work extends this idealized thermo-mechanical damage model by evaluating actual field data to determine a potential upper bound life estimate. This assessment also provides insight into practical techniques for equipment operators to identify design and operational opportunities to extend the service life of coke drums for their specific service environments. A modern trend of specifying higher chromium and molybdenum alloy content for drum shell material in order to improve low cycle fatigue strength is seen to be problematic; rather, the use of lower alloy materials that are generally described as fatigue tough materials are better suited for the high strain-low cycle fatigue service environment of coke drums. Materials such as SA 204 C (C – ½ Mo) and SA 302 B (C – Mn – ½ Mo) or SA 302 C (C – Mn – ½ Mo – ½ Ni) are shown to be better candidates for construction in lieu of low chromium alloy steel materials such as SA 387 grades P11 (1¼ Cr – ½ Mo), P12 (1 Cr – ½ Mo), P22 (2¼ Cr – 1 Mo) and P21 (3 Cr – 1 Mo).
APA, Harvard, Vancouver, ISO, and other styles
6

Chan, Kwai S., Michael P. Enright, Jonathan P. Moody, Benjamin Hocking, and Simeon H. K. Fitch. "Life Prediction for Turbopropulsion Systems Under Dwell Fatigue Conditions." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69742.

Full text
Abstract:
The objective of this investigation was to develop an innovative methodology for life and reliability prediction of hot-section components in advanced turbopropulsion systems. A set of three generic time-dependent crack growth models was implemented and integrated into the DARWIN® probabilistic life-prediction code. Using the enhanced risk analysis tool and material constants calibrated to IN 718 data, the effect of time-dependent crack growth on the risk of fracture in turboengine component was demonstrated for a generic rotor design and a realistic mission profile. The results of this investigation confirmed that time-dependent crack growth and cycle-dependent crack growth in IN 718 can be treated by a simple summation of the crack increments over a mission. For the temperatures considered, time-dependent crack growth in IN 718 can be considered as a K-controlled environmentally-induced degradation process. Software implementation of the generic time-dependent crack growth models in DARWIN provides a pathway for potential evaluation of the effects of multiple damage modes on the risk of component fracture at high service temperatures.
APA, Harvard, Vancouver, ISO, and other styles
7

Mekha, Basim. "Proposed Methodology for Extending the Lives of Steel Catenary Risers Connected to Floating Production Systems." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54918.

Full text
Abstract:
Extending the life of steel catenary risers is becoming one of the main subjects of interest nowadays as many steel catenary risers (SCRs) are approaching their design lives. Many of the risers in this situation are export risers, which may require extended design lives due to development of new production fields being tied back to the floating facilities they service. There have been no specific methodologies or defined approaches for dealing with this subject. The conservatism of the design methodology, which is usually adopted for the detailed design of new risers, will have to be adjusted when evaluating existing risers with known environmental and operational history as well as fabrication and installation data. This paper will describe a proposed methodology and potential approach for extending the lives of existing steel catenary risers (SCRs) connected to floating structures in the Gulf of Mexico. It will highlight the essential steps that should be taken to evaluate the risers’ current status and to determine their already consumed fatigue lives. The proposed methodology for calculating the riser consumed fatigue damage will be discussed and compared with the typical but conservative approach that is usually taken during the detailed design of new risers. The next step will then be the calculation of the riser remaining life including the treatment of its already consumed fatigue damage. The proposed methodology will also cover the relationship between the safety factors and availability of actual data during the life of the risers. Fracture mechanics assessment for riser welds and their flaws is another step that needs to be performed to support the fatigue analysis calculation. Internal and external inspection of the risers, including pipe welds, pipe corrosion and possible pitting, is a work in progress at this stage and would probably be essential part of any riser life extension program. Some discussion will also be provided for the risers’ special components (e.g. strakes, coating, cathodic protection, and top termination units) to ensure all aspects are covered in the evaluation of the riser life extension.
APA, Harvard, Vancouver, ISO, and other styles
8

Krafft, R., and S. Mosset. "A Probabilistic Method for the Fatigue Life Assessment of Powder Metallurgy Parts of Aircraft Engines." In ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/95-gt-218.

Full text
Abstract:
This paper will present a probabilistic approach developed in order to assess the fatigue life of aircraft engine parts (turbine disks) obtained by powder metallurgy technique. First of all, the main issues will be pointed out and the theoretical principles of the method will be described. Then the design implications and the experimental correlation will be emphasised. The scale effect is a major concern for the fatigue life assessment of a powder metallurgy part. It no longer allows the designer to directly evaluate the life of a massive part from experimental results based on small specimen fatigue tests as it is done in the classical methodology. In order to correctly describe this scale effect, incubation sites (inhomogeneities like ceramic inclusions) must be characterised. The size of these inhomogeneities and their positions in the part appeared to be the most relevant parameters. Hence the methodology developed at Snecma integrates the scale effect scatter through a binomial probability distribution as well as a temperature and stress dependent life evaluation for each inhomogeneity size and position. The life calculation of a part implies an analysis of its whole volume and surface. An iterative process determines the number of cycles corresponding to a global reliability level requirement for the part. The complete methodology is then validated by comparing the calculated initiation distribution with experimental results on small specimens and test disks.
APA, Harvard, Vancouver, ISO, and other styles
9

Kim, Sang-Won, Nobuhiro Yoshikawa, Hiroshi Kobayashi, Toshiro Fujisawa, and Takeru Sano. "Numerical Fatigue Life Evaluation With Experimental Results for Type III Accumulators." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84188.

Full text
Abstract:
Composite Reinforced Accumulator (CRA) is widely used in hydrogen stations. A high-cost pressure cycle test is mandatory to ensure the safety of accumulator in present regulations. To reduce the high cost, the aim is to develop a methodology of numerical fatigue life prediction of CRA with results of pressure cycle tests. An axisymmetric finite element model for the Type III accumulator is created and actual loading process including autofrettage pressure is simulated. Stress amplitude caused by pressure cycle is evaluated based on the instructions in KD-3 of ASME BPVC VIII 3-2015. By comparing stress amplitude distributions with the leak positions after the pressure cycle test, and plotting the results in the design fatigue curve, it could be shown that fatigue life prediction of Type III accumulator can be done by precise finite element analysis of the liner including dome part, where the principal axes of stress change in pressure cycle.
APA, Harvard, Vancouver, ISO, and other styles
10

Heckmann, Klaus, Jürgen Sievers, Tim Schopf, Xaver Schuler, Ruth de Acosta, Peter Starke, Christian Boller, Michael Jamrozy, Marina Knyazeva, and Frank Walther. "StrainLife: Efficient Fatigue Life Data Generation for an Enhanced Ageing Assessment of Metallic Components." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84538.

Full text
Abstract:
Pressurized pipes in hot water environment are subject to ageing mechanisms such as fatigue and environmental-assisted fatigue. These ageing effects limit the in-service time of components due to the possibility of crack formation, initiation and growth. Furthermore, uncertainties in life time assessment evolve as a consequence of increased scattering and resulting deviations in material properties. The lack of appropriate information requires safety-oriented design and conservative margins in the acceptable operation time. In this contribution, investigations on methods for an improved assessment of fatigue life assessment based on microstructural aspects (specifically in the view of piping systems) are presented. The focus is on the metastable austenitic steel AISI 347 (X6CrNiNb18-10) under boiling water reactor operational conditions. In addition to strain-controlled fatigue tests and the hysteresis information, microstructural characterizations of the damage evolution are performed. Fatigue tests are equipped with magnetic and resistometric sensors to measure a different kind of material response correlated with the damage states. The information obtained is used for an improved derivation of fatigue life evaluations of piping systems. The StrainLife approach and its specific instrumentation is proposed and discussed. In this approach, the number of strain-controlled fatigue tests is basically reduced by an order of magnitude when compared to traditional procedures. A software tool (as a module of the structural analysis code PROST) has been developed to assist users in evaluating and incorporating the respective data and to derive the subsequent fatigue life curves. As an outlook, further development is addressed to transfer the methodology to the assessment of residual fatigue life of components being exposed to ageing in operation.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Methodology for evaluating the fatigue life"

1

Garsa, Adam, Julie K. Jang, Sangita Baxi, Christine Chen, Olamigoke Akinniranye, Owen Hall, Jody Larkin, Aneesa Motala, Sydne Newberry, and Susanne Hempel. Radiation Therapy for Brain Metasases. Agency for Healthcare Research and Quality (AHRQ), June 2021. http://dx.doi.org/10.23970/ahrqepccer242.

Full text
Abstract:
Objective. This evidence report synthesizes the available evidence on radiation therapy for brain metastases. Data sources. We searched PubMed®, Embase®, Web of Science, Scopus, CINAHL®, clinicaltrials.gov, and published guidelines in July 2020; assessed independently submitted data; consulted with experts; and contacted authors. Review methods. The protocol was informed by Key Informants. The systematic review was supported by a Technical Expert Panel and is registered in PROSPERO (CRD42020168260). Two reviewers independently screened citations; data were abstracted by one reviewer and checked by an experienced reviewer. We included randomized controlled trials (RCTs) and large observational studies (for safety assessments), evaluating whole brain radiation therapy (WBRT) and stereotactic radiosurgery (SRS) alone or in combination, as initial or postoperative treatment, with or without systemic therapy for adults with brain metastases due to non-small cell lung cancer, breast cancer, or melanoma. Results. In total, 97 studies, reported in 190 publications, were identified, but the number of analyses was limited due to different intervention and comparator combinations as well as insufficient reporting of outcome data. Risk of bias varied; 25 trials were terminated early, predominantly due to poor accrual. Most studies evaluated WBRT, alone or in combination with SRS, as initial treatment; 10 RCTs reported on post-surgical interventions. The combination treatment SRS plus WBRT compared to SRS alone or WBRT alone showed no statistically significant difference in overall survival (hazard ratio [HR], 1.09; confidence interval [CI], 0.69 to 1.73; 4 RCTs; low strength of evidence [SoE]) or death due to brain metastases (relative risk [RR], 0.93; CI, 0.48 to 1.81; 3 RCTs; low SoE). Radiation therapy after surgery did not improve overall survival compared with surgery alone (HR, 0.98; CI, 0.76 to 1.26; 5 RCTs; moderate SoE). Data for quality of life, functional status, and cognitive effects were insufficient to determine effects of WBRT, SRS, or post-surgical interventions. We did not find systematic differences across interventions in serious adverse events radiation necrosis, fatigue, or seizures (all low or moderate SoE). WBRT plus systemic therapy (RR, 1.44; CI, 1.03 to 2.00; 14 studies; moderate SoE) was associated with increased risks for vomiting compared to WBRT alone. Conclusion. Despite the substantial research literature on radiation therapy, comparative effectiveness information is limited. There is a need for more data on patient-relevant outcomes such as quality of life, functional status, and cognitive effects.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Methodology for evaluating the fatigue life' for particular source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography