基于ABAQUS的混凝土软化曲线逆推分析开发应用

ABAQUS-based development and application of inverse analysis on concrete softening curve

本文根据相关三点弯曲梁试验数据建立数值仿真模型对混凝土双线性软化曲线进行了逆推分析。为获得能够准确反映混凝土断裂过程区软化特性的软化曲线,通过Python脚本自编程,利用进化算法,以双线性软化曲线参数为优化变量,以数值仿真模型计算得到的P-CMOD曲线同试验测得的P-CMOD曲线之间的误差为目标函数,在ABAQUS平台上开发了对混凝土双线性软化曲线逆推分析程序。针对切口三点弯曲梁的逆推分析结果显示,双线性软化曲线第一下降段斜率决定数值计算得到的P-CMOD曲线的荷载峰值,逆推得到的P-CMOD曲线的荷载峰值同试验测得的P-CMOD曲线的荷载峰值之间的误差不超过5%,逆推得到的断裂能同试验计算得到的断裂能之间误差不超过10%,说明该方法获得的软化曲线能够较准确地反映混凝土断裂过程的结构响应,验证了所提方法的有效性。

The inverse analysis of concrete bilinear softening curve is made herein by establishing numerical simulation model in accordance with the relevant three point bending beam test. In order to correctly reflect the softening curve of the softening characteristics of the zone of concrete fracturing process,a program for the inverse analysis on concrete bilinear softening curve is developed on the platform of ABAQUS with evolutionary algorithms by taking the parameters of bilinear softening curve as the optimization variables and the error between P-CMOD curves measured by P-CMOD curve calculated with the numerical simulation model and the relevant test as the objective function through Python self-programming. From the inverse analysis on the threepoint bending notched beam,the result shows that the peak load of P-CMOD curve obtained from the numerical calculation is determined by the primary decreasing section of the bilinear softening curve,while the error between the peak load of P-CMOD curve and that measured by the relevant test is not over 5% and the error between the fracturing energy obtained from the inverse analysis and that from test calculation is not over 10%; from which it is indicated that the softening curve obtained from this method can correctly reflect the structural response of the fracturing process of concrete,thus the effectiveness of it is verified as well.