Abstract:

Using the Double Cantilever Beam (DCB) specimen made by 30CrMnSi2A and dynamic finite element method (DFEM) combined with the J′ integral independent of far field path, the dynamic crack propagation toughness KID is calculated. An estimation and analysis of different engineering methods for estimating KID are carried out. The empirical Kanninen′s formula is improved to predict the limiting speed VL easily for different Poisson ratios of materials. Meanwhile, it is shown that the material constant m is dependent on initiation and arrest length of the crack and associated with the radius of the crack tip. A formula for predicting m is given.

Key words: DFEM, far- field pat h-independent integra l, cr ack propagation t oughness, dynamicar rest toughness