Secondary Development On The Constitutive Model Of Steel For Explicit Dynamic Elements Of ABAQUS

With the accelerated pace of economic development, civil construction is growing with each passing day, more and more large bridge structure occurs among cities.China is one of the world’s most earthquake-prone countries. With the impact of the collision between beams, collision between abutment and beam and falling beam,bridge is likely to occur partial or total collapse.Bridge will usually enter into elastoplastic stage when it under seismic action. Conventional elastic analysis methods have been unable to accurately describe the actual behavior of structures. How to carry out structual elastic-plastic analyzes accurately and effectively has increasingly become the force of academic research.The most commonly used general finite element software are ANSYS,MSC.MARC,ABAQUS,ect.There have been many scholars using them for structual dynamic analyzes. ABAQUS finit element software not only has a strong ability to solve nonlinear problems, but also has a good openness to provide users with a number of subroutines interface that allows the user to customize and extend the function of ABAQUS.In this paper,steel uni-axial constitutive relationship model has been studied. Based on user-defined material subroutine interface(VUMAT) of steel material constitutive model for secondary development to describe the mechanical behavior of reinforced concrete structures under cycling loads more accurately. The details are as follows:(1)Though ABAQUS, Intel Visual Fortran as well as Microsoft Visual Studio these three software integration, solves the connection problem between ABAQUS subroutine and the main program.(2)Compared on the basis of many existing constitutive models for steels,choose the most applicable model to this study - constitutive model of multi-line reinforcement under cyclic loads.Establishing reinforced material model VUMAT program detailing the meaning of the related variable in the subroutine code, parameter settings and how to use it.(3)Separately via a reinforced concrete columns and steel unit for VUMAT users of this material mathematical verification subroutine, VUMAT subroutine should eventually be used for seismic response analysis.This paper take the stiffness degradation and strength degradation of steel that under cyclic loading into account.It can be used for simple beams components nonlinear analysis under seismic loads.