CRACK TRAJECTORIES UNDER MIXED-MODE AND NONPROPORTIONAL LOADING

A novel testing procedure for mixed mode crack propagation is presente d; it offers the possibility of non-proportional loading and of changi ng the crack trajectory during testing, features which allow non-tradi tional mixed mode tests which, in turn, may help in discriminating mix ed mode fracture criteria. Detailed experimental stable crack trajecto ries and corresponding load-CMOD (or load-displacement) curves from th ese non-traditional tests are proposed as benchmarks for numerical pro grams of mixed mode crack propagation.