EFFECTIVE ANCHORAGE LENGTH FOR SRHSHPC COMPOSITE STRUCTURE

摘要

The interfacial shear stress transfer capacity between steel and concrete has great influence on the mechanical performance of steel-concrete composite structural members. Therefore, study on the interfacial shear stress transfer mechanism between steel and concrete is of great significance. The fracture mechanics method is an effective way to analyze the interfacial crack porpagation and shear stress transfer capacity between steel and concrete. In this paper, the nonlinear fracture mechanics (NLFM) method is employed to investigate the interfacial behavior between embedded steel and concrete for SRHSHPC composite structural members. Considering the stress equilibrium, the interfacial governing differential equation is derived based on some basic assumptions. By introducing a simplifed bond stress-slip constitutive model with softening, the closed-form solutions for the distribution of bond stress, relative slip and steel stress are obtained and the anchorange force between embedded steel and concrete can be calculated accordingly. The analytical results show that the peak value of bond stress transfers towards the free end gradually after bond softening occurs. At last the effective anchorge length for SRC composite structure, which is defined as the length needed to attain the maximum anchorage force, is proposed on the basis of the analytical results.