基于ABAQUS纤维梁的钢筋混凝土材料模型二次开发

Secondary Development on Constitutive Model of Concrete and Steel for Beam Element in ABAQUS

目的研究ABAQUS纤维梁钢筋混凝土材料本构模型,以解决软件中缺乏可用的三维梁单元约束混凝土材料模型及软件自带金属塑性材料模型无法考虑加卸载过程中刚度退化等问题.方法采用FORTRAN语言,基于经典混凝土和钢筋单轴材料本构模型,开发用于显式模块的钢筋混凝土梁单元材料子程序.首先,通过对钢筋的变幅值拉伸试验和素混凝土柱往复拉、压过程的模拟对子程序的有效性进行了初步验证;其次,分别采用不同的材料本构模型对钢筋混凝土梁、柱拟静力试验进行数值仿真,验证子程序用于构件分析的准确性和有效性;最后,以一个12层方钢管混凝土平面框架结构为例,分别建立二维和三维有限元模型,并进行地震作用下动力弹塑性时程分析.结果钢筋混凝土梁、柱试验的数值模拟结果与试验结果吻合良好,对比误差均小于4%,对钢管混凝土平面框架结构弹塑性地震反应分析结果也较为理想.结论采用不同钢筋加载规则得到的构件荷载-位移骨架曲线大致相同,但滞回捏拢行为有显著改变.与ABAQUS自带材料本构模型相比,笔者所开发的材料子程序可以更好地反映循环荷载作用下钢筋混凝土构件及结构的力学特性,可用于构件及结构的非线性分析.

To study the constitutive model of reinforced concrete material for ABAQUS fiber beam,and solve the problems that the lack of confined concrete constitutive model applied to three-dimensional（3 D） beam element in ABAQUS and that the owned metal constitutive model in ABAQUS cannot consider the effect of stiffness degradation,based on the classical uniaxial constitutive models of concrete and reinforcing steel,a VUMAT subroutine,involved the behavior of concrete damage plasticity and two kinds cyclic loading constitutive models of reinforcing steel,was compiled by FORTRAN. Firstly,the validity of subroutine was preliminary verified by means of the numerical simulation about a tension and compression test for reinforcing steel and plain concrete column; secondly,the numerical simulations for unidirectional quasi-static loading test of reinforced concrete（RC） column and beam were conducted,and the simulation results have a good agreement with experimental results,and relative errors are less than 4%. it is shown that the subroutine can simulate the hysteretic performance of RC members well,Meanwhile,comparing with the calculated results by the owned steel constitutive model in ABAQUS,the results showthat the selection of reinforcing hysteretic constitutive model has no obvious effect on the skeleton curve.However,the behavior of hysteresis is significantly changed. Finally,the dynamic elastic-plastic time-history analysis for a 12 storey concrete filled steel tube（CFST） frame structure was conducted,and the simulated resulted is also satisfactory. So it is shown that the developed subroutine is available to apply to the non-linear analysis of structures under dynamic loadings.