低速冲击碰撞有限元分析中混凝土动态破坏面修正方法

A MODIFIED METHOD FOR DEFINING CONCRETE DYNAMIC FAILURE SURFACE UNDER LOW-SPEED IMPACT FINITE ELEMENT ANALYSIS

为了将混凝土材性试验数据更好的应用到冲击有限元仿真中,分析了常用混凝土本构关系中的应变率参数作用特点,提出了一种基于构件试验结果线性插值的混凝土动态破坏面修正方法来减小构件响应计算误差,采用两组钢筋混凝土梁侧向撞击试验标定了修正系数,并以另两组试验对标定的参数进行验证,四组仿真试验均取得良好结果。采用提出的方法,建立了评价混凝土本构关系适用性的评价体系。研究表明:提出的动态破坏面修正方法能够较好地减小构件响应计算误差,准确地反映钢筋混凝土构件在冲击碰撞情况下的力学响应;应用提出的评价体系可以有效评估混凝土本构关系的适用性。

To better apply concrete material test data to impact finite element analysis, the effect of strain rate parameters of general concrete constitutive model was analyzed. A linear interpolation method based on member test results was presented to eliminate the calculation error by modifying the concrete dynamic failure surface. A group of four lateral impact tests of reinforced concrete beams was employed for numerical simulation. Two were used to derive the proposed modified method, and the other two to testify the accuracy of the correction factor. Results of the four simulation were accurate. Moreover, an evaluation method was proposed to evaluate the adaptability of concrete constitutive models based on the modified method. It is shown that the modified method of determining dynamic failure surface reduces the calculation error and represents the dynamic response of concrete accurately. The evaluation method can assess the applicability of concrete constitutive models effectively.