Scatter of fatigue data owing to material microscopic effects

作     者：TANG XueSong 

作者机构：Department of Mechanics School of Civil Engineering and Architecture Changsha University of Science and Technology 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2014年第57卷第1期

页      面：90-97页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0704[理学-天文学] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grant No.51378081) 

主　　题：fracture mechanics fatigue crack growth multiscaling effect S-N curve microscopic effect trans-scale 

摘      要：A common phenomenon of fatigue test data reported in the open literature such as S-N curves exhibits the scatter of points for a group of same specimens under the same loading *** reason is well known that the microstructure is different from specimen to specimen even in the same ***,a fatigue failure process is a multi-scale problem so that a fatigue failure model should have the ability to take the microscopic effect into account.A physically-based trans-scale crack model is established and the analytical solution is obtained by coupling the micro-and *** is the trans-scale stress intensity factor as well as the trans-scale strain energy density(SED)*** taking this trans-scale SEDF as a key controlling parameter for the fatigue crack propagation from micro-to macro-scale,a trans-scale fatigue crack growth model is proposed in this work which can reflect the microscopic effect and scale transition in a fatigue *** fatigue test data of aluminum alloy LY12 plate specimens is chosen to check the *** S-N experimental curves for cyclic stress ratio R=0.02 and R=0.6 are *** scattering test data points and two S-N curves for both R=0.02 and R=0.6 are exactly re-produced by application of the proposed *** is demonstrated that the proposed model is able to reflect the multiscaling effect in a fatigue *** result also shows that the microscopic effect has a pronounced influence on the fatigue life of specimens.