Adel Basiri, Ebrahim Amini,
Volume 12, Issue 1 (3-2022)
Abstract
The objective of the present paper is to assess the capability of several classical damage models in prediction of service lifetime of engine components subjected to Thermo-mechanical Fatigue (TMF) loading. The focus of the present study is based on efficient and robust predictive tools which are suitable in industrial development process, thus the classical fatigue damage models are selected to perform such a tsk. In the classical framework, three strain-based models including Manson-Coffin, Smith-Watson-Topper and Ostergren models and one plastic strain energy-based model are examined. Besides, some correction factors are added to the Manson-Coffin, Ostergren and plastic strain energy models regarding the mean stress and temperature effects. The statistical analysis of the models is carried out utilizing the Low-cycle fatigue and Thermo-mechanical Fatigue tests on standard specimens of A356 aluminum alloy. The analysis indicated that modified Ostergren model is the most reliable model in fatigue lifetime description of the A356 alloy among the others. The studied engine component is a passenger-car diesel engine cylinder head made of A356 aluminum alloy. The temperature, stress and strain distribution fields of the component are considered as the given boundary conditions from our previous work as they are not in the scope of the present investigation. The selected damage models based on the best accuracy identified during statistical analysis are introduced into the ABAQUS software. The modified Ostergren model presented the most accurate and realistic results based on empirical observations of fatigue crack area in diesel engine cylinder heads studied in the literature.
Mr. Milad Arianfard, Dr. Abbas Soltani,
Volume 14, Issue 2 (6-2024)
Abstract
In this paper, the strength of the gear shifting blocker for Peugeot gearbox is investigated. A hardened steel sheet is used inside the plastic part of shifting blocker to strengthen it. According to the feedback from the customer that this part fails in some conditions, some suggestions for its improvement are presented. In this research, two proposed correction designs are presented to increase the strength of the gear shifting locker by changing on the considered steel sheet. Abaqus software has been used to model the gear shifting blocker and analyze the stress of parts by finite element method. In order to validate the analytical results and choose the proper proposed design to strengthen the blocker part, some experimental tests are performed on the tension-compression test device. By comparing the results of the numerical analysis, it can be observed that the first and second modification designs have improved the stresses of blocker plastic part by 18% and 45%, respectively.
