Stability of crack propagation associated with fracture energy determined by wedge splitting specimen

The wedge splitting test is performed on notched shaped specimens that enables the determination of energies for large fracture surfaces and material exhibiting brittle behaviour. A stability condition is deduced and found to depend on the Young's modulus and the R-curve behaviour. The latter is defined by the fracture toughness K_R and fracture energy R_c both of which depend on the crack length. A stable crack propagation is enhanced by high ratios of K′_R/K_R and R_c/K_R². The wedge loading tends to behave like raising the rigidity of the testing machine. The results are applied on an example with a special geometry.