Showing papers by "Zhong Chen published in 1997"

The blister test – Transition from plate to membrane behaviour for an elastic material

Abstract: The crack extension force has been calculated for the blister test when the blister is in transition from plate-like to membrane behaviour. Simple equations are given for the crack extension force that are accurate to better than 1%. The mode-mixity of interfacial fracture in the blister test is discussed and it is shown that the interfacial fracture energy is likely to increase with decrease in thickness of the film. In practical tests, the behaviour of a blister is likely to be nearer to a plate than a membrane.

The Effect of Geometry and Size on the Growth of Ductile Fracture

Abstract: Ductile crack propagation is modelled for deeply side-grooved double cantilever beam (DCB) and compact tension (CT) specimens using simple beam on elastoplastic foundations. The side grooves dominate the constraint at the crack tip so that the deformation within the fracture process zone is one of uniaxial strain. Under these conditions there is little change in constraint with crack growth and the specific essential fracture energy is constant. In DCB specimens there is self similar crack propagation, but there is a rising JR curve that is size dependant. In small CT specimens the crack growth is not self similar and the fracture work is not constant. Under these conditions even the initiation J is not necessarily equal to the specific essential energy.