A FE model to evaluate the resisting capacity of RC beams and columns under blast loading based on P-I diagram

Abstract

An improved numerical model to evaluate the resisting capacity of RC beams and columns subjected to blast loading is proposed in this paper. To describe the bending behavior of a structure, the moment-curvature relation of a RC section is employed with the definition of a dynamic increase factor (DIF) as a function of the curvature rate. The direct shear failure is also considered through adoption of the dynamic shear stress-slip relation proposed by Krauthammer et al. Upon verification of the validity of the proposed numerical model through a comparison between the obtained numerical results and the experimental data, additional parametric studies are performed for the pressure-impulse (P-I) diagrams to demonstrate that the SDOF method, which has been popularly used in constructing the P-I diagrams, has a limitation in determining the blast resisting capacity of RC members, especially in describing the shear failure mode. Since the direct three-dimensional (3-D) nonlinear blast analysis of structural members is time-consuming and costly, the direct use of the 3-D analysis appears to be extremely difficult whereas the use of the proposed numerical model will provide an alternative in construction the P-I diagrams.