It has been postulated that, with tensile loading conditions, micro-cracks onthin hard film act as stress concentrators enhancing plastic deformation of the substrate materialin their vicinity. Under favorable conditions the localized plastic flow near the cracks may turninto macroscopic plastic strain thus affects the plasticity behaviors of the substrate. Thisphenomenon is analyzed quantitatively with finite element method with special attention focused onthe analysis and discussion of the effects of plastic work hardening rate, film thickness and crackdepth on maximum plastic strain, critical loading stress and the size of the local plasticdeformation zone. Results show that micro-cracks on thin hard film have unnegligible effects on theplasticity behaviors of the substrate material under tensile loading.
