A nonlinear fatigue damage‐healing model for copper film by LSP

Abstract

The healing variable and enhancement variable were first defined by the fatigue ductility, and then based on the relationship of the damage variable, the healing variable and the enhancement variable, a nonlinear fatigue damage‐healing model was proposed for predicting the fatigue life of the healed copper film by laser shock peening (LSP). The nonlinear fatigue damage cumulative process was considered in the model for the original specimen without LSP under constant and variable amplitude loadings. The results showed that the proposed nonlinear fatigue damage‐healing model can predict the residual fatigue life for the damaged copper film specimen well.

Experimental investigations and damage growth modeling of EN‐AW 2024 aluminum alloy under LCF loading accounting creep pre‐deformation

“…A critical plane approach is often used based on the normal and share strain energy density parameter 43–45 or a special stress function is introduced, being a combination of normal and shear stresses 46,47 . The damage accumulation model is often made dependent only on inelastic hysteresis strain energy per cycle 48–51 . The well‐known Smith‐Watson‐Topper (SWT) model 52–55 is widely used also, where the damage state variable is a combination of the total strain amplitude and maximum stresses in the loading cycle.…”

“…46,47 The damage accumulation model is often made dependent only on inelastic hysteresis strain energy per cycle. [48][49][50][51] The well-known Smith-Watson-Topper (SWT) model [52][53][54][55] is widely used also, where the damage state variable is a combination of the total strain amplitude and maximum stresses in the loading cycle. In continuous damage mechanics, the damage growth process is often dependent on plastic deformation.…”