Shear Failure Analysis with Modelling Multiple Discontinuities in a Concrete Beam Using XFEM

Abstract

AbstractDespite intensive research in the last decades, the shear force transfer and crack propagation in structural concrete members is still disputed. In order to investigate the load bearing behaviour, an understanding of crack growth and flow of internal forces is essential. In this context, various techniques have been developed in the recent years to analyze the crack pattern and to detect fracture failure in advance. This paper presents the investigation of discrete crack propagation and the shear bearing behaviour of a concrete beam without transverse reinforcement using the extended finite element method (XFEM). By applying the cohesive zone model (CZM) under different traction separation laws and describing the damage evolution, crack growth is modelled with several discontinuities. In this framework, the load bearing behavior and the development of the crack with its dimensions are discussed. Linear, bilinear and nonlinear softening curves of the fracture process zone for the investigation of one to several cracks are presented. The numerical analysis are validated by experimental results. The findings are compared and evaluated with the isotropic material model ‘concrete damage plasticity’ (CDP). The smeared and discrete crack pattern are contrasted. It is concluded that the numerical analyses make useful predictions of the fracture behavior of reinforced concrete members and provide further possibilities for research purposes.KeywordsCrack propagationDamage mechanicsExtended finite element methodCohesive zone modelConcrete damage plasticity