Abstract: The fatigue face-crack growth behavior in explosive bonded double-layer metal composite plate (LY12/Cu) was investigated. The results indicate that, the elastic-plastic mismatch of components has significant influence on the near-tip “driving force” of fatigue crack growth. It is demonstrated that the crack-tip is “shielded” from the remote loads when it approaches the interface from the weaker material whose yielding strength and elastic module are lower. And the effective “driving force” at the crack tip is greater than the remote loads when it approaches the interface from the stronger material whose yielding strength and elastic module are higher. The shielding and amplification of the near-tip “driving force” from the components’ elastic-plastic mismatch are more and more obvious with the crack-tip approaching the interface. However, t h e ranges of elastic mismatch and plastic mismatch taking effect are not the same. The elastic mismatch acts from the fatigue crack starting growth to crack-tip contacting interface, the plastic mismatch only acts after the crack-tip plastic zone contacting the interface.
Fatigue crack propagation in LY12/Cu double-layer metal laminate (Ⅰ) ──Face-crack
Abstract:
The fatigue face-crack growth behavior in explosive bonded double-layer metal composite plate (LY12/Cu) was investigated. The results indicate that, the elastic-plastic mismatch of components has significant influence on the near-tip "driving force" of fatigue crack growth. It is demonstrated that the crack-tip is "shielded" from the remote loads when it approaches the interface from the weaker material whose yielding strength and elastic module are lower. And the effective "driving force" at the crack tip is greater than the remote loads when it approaches the interface from the stronger material whose yielding strength and elastic module are higher. The shielding and amplification of the near-tip "driving force" from the components' elastic-plastic mismatch are more and more obvious with the crack-tip approaching the interface. However, the ranges of elastic mismatch and plastic mismatch taking effect are not the same. The elastic mismatch acts from the fatigue crack starting growth to crack-tip contacting interface, the plastic mismatch only acts after the crack-tip plastic zone contacting the interface.