DIMENSIONLESS LOAD - DISPLACEMENT RELATION AND ITS APPLICATION TO CRACK-PROPAGATION PROBLEMS

The dimensionless load (P) and load-point displacement (u) are introduced to discuss crack propagation problems. The P-u relation for the case of equilibrium crack propagation in any linear elastic material is demonstrated to lie on a single universal fracture curve independent of the material. The concept of the universal P-u relation is extended to yield a direct and simple form of the dimensionless total energy. The evaluation of the nonlinear fracture resistance parameter of a polycrystalline graphite material, as an example, is demonstrated.