TY  - EJOU
AU  - Kwofie, S. 

TI  - Relaxation of Residual Stress under Fatigue Load Described in Terms of Cyclic-Plastic Deformation Model
T2  - Structural Durability \& Health Monitoring

PY  - 2012
VL  - 8
IS  - 4
SN  - 1930-2991

AB  - Fatigue life of components may be enhanced by mechanical surface treatments, such as shot penning, which induce compressive residual stresses in the component's surface. Under cyclic/fatigue loads, however, relaxation of the residual stress may occur thus, reducing the optimum benefit of the surface treatment. For health monitoring / life prediction under such conditions it is important to be able to assess stress relaxation in real-time. However, the phenomenon of cyclic relaxation of residual stress is not well understood and its tracking during component operation is a technical challenge. By means of cyclic plastic deformation model and the Matlab/Simulink Program cyclic relaxation of residual stress is simulated. Simulated results show that residual stress relaxation under cyclic loading is associated with mean-strain shift, which is indicative of stress redistribution. The significance of this mean strain shift is briefly discussed in terms of tracking and quantitatively determining residual stress relaxation in real-time. Reduction in residual stress may be estimated as the product of <i>mean-strain shift</i> and the <i>elastic modulus</i> of the material.
KW  - Residual stress
KW  -  stress amplitude
KW  -  hysteresis loops
KW  -  mean-strain shift
KW  -  residual stress relaxation
KW  - 

DO  - 10.32604/sdhm.2012.008.295