Investigation on 3D fatigue crack propagation in surface-cracked specimens  

作　　者：X.Li H.Yuan J.Y.Sun 

机构地区：[1]Department of Mechanical Engineering, University of Wuppertal

出　　处：《Theoretical & Applied Mechanics Letters》2013年第4期18-22,共5页力学快报（英文版）

基　　金：supported by the German Science Foundation(DFG, YU119/5-2)

摘　　要：In the present work the fatigue crack growth in AISI304 specimens is investigated experimentally. In 3D finite element analysis the virtual crack closure technique is applied to calculate distributions and variations of the stress intensity factor along the surface crack front. It is confirmed that the stress intensity factor along the surface crack front varies non-uniformly with crack growth. Crack growth rate is proportional to the stress intensity factor distribution in the 3D cracked specimen. The fatigue crack growth in surface cracked specimens can be described by the Forman model identified in conventional compact tension specimens. For crack growth in the free specimen surface the arc length seems more suitable to quantify crack progress. Geometry and loading configuration of the surface cracked specimen seem to not affect the fatigue crack growth substantially.In the present work the fatigue crack growth in AISI304 specimens is investigated experimentally. In 3D finite element analysis the virtual crack closure technique is applied to calculate distributions and variations of the stress intensity factor along the surface crack front. It is confirmed that the stress intensity factor along the surface crack front varies non-uniformly with crack growth. Crack growth rate is proportional to the stress intensity factor distribution in the 3D cracked specimen. The fatigue crack growth in surface cracked specimens can be described by the Forman model identified in conventional compact tension specimens. For crack growth in the free specimen surface the arc length seems more suitable to quantify crack progress. Geometry and loading configuration of the surface cracked specimen seem to not affect the fatigue crack growth substantially.

关 键 词：surface crack crack front fatigue crack growth 3D stress intensity factor 

分 类 号：TG115[金属学及工艺—物理冶金] TP391.41[金属学及工艺—金属学]