Effect of Soft Interphase On the Crack Growth in The Bimetallic Laminate
Jia Purong,He Jiawen,Li Nian,Zhang Yuanchong
(Northwestern Polytechnical Unviersity, Xi'an 710072)

Abstract: This paper analyzes the mechanics behavior of crack growth normal to the interface by using the bimetallic laminate with soft interphase. Experiments of steel/aluminium laminate with single edge crack show that the fatigue crack growth rate da/dN is decreased when the crack tip is reached the interface. And the crack deviation will occur in the interphase. The change of the stress and strain in front of the crack is analyzed by use of the finite element software. The calculated results show that larger plastic strain occurs in soft aluminium  interphase. So the crack growth resistance is increased, and the crack growth force ĶĪK is decreased. It leads to the decrement of da/dN. The T-stress in soft interphase is higher relatively. This causes the deviation of crack growth.
Keywords: metallic laminate, soft interphase, plastic strain, crack growth rate.