Semi-analytical element method for double-K fracture parameters computations in concrete
混凝土双K断裂参数计算的半解析有限元法

The double-K tracture criterion describes initiation, stable propagation and unstable propagation of cracks in concrete structures. The corresponding double-K fracture parameters (initial cracking roughness K_(IC)~(ini) and unstable fracture toughness K_(IC)~(ini)) introduced in the criterion are determined using a simple experiment method combing with an analytical evaluation based on the cohesive force on the fictitious crack zone. Based on the Hamiltonian governing equations of plane elasticity for sectorial domain, the variable separation and eigenfunction expansion techniques are employed to develop a novel analytical finite element for the fictitious crack propagation linear force model in fracture mechanics of concrete in this paper. The new analytical element can be implemented into FEM program systems to solve computational problems of double-K fracture parameters for concrete cracked plane structures with arbitrary shapes. Numerical results indicate that the method is efficient and accurate.