混凝土本构模型及其动态有限元算法研究

混凝土的力学性质及其本构研究是当前力学领域的一个重要课题。混凝土的实验数据表明其力学性质表现出很强的各向异性及并且在高加载速率的情况下，混凝土的性质物美价廉 时时明显不同。这就要求我们采用应变率相关的弹粘弹性本构模型来描述混凝土的力学行为。本语文从Ｏｔｔｏｓｅｎ的四参数混凝土模型出发，引进损伤和应变率的影响，参考关联塑性的理论，改进了混凝土的本构模型。为了把混凝土的数值模拟推向实用，本文概括混凝土

THE RESEARCH OF THE CONSTITUTIVE MODEL OF CONCRETE USING THE DYNAMIC FINITE ELEMENT METHOD

The research of the mechanical characteristics and constitutive model of concrete is an important topic in the field of engineering mechanics. From the experimental data, it shows that the mechanical behavior of the concrete exhibits anisotropy and is obviously different from that of the quasi-static loading under high rate of loading condition. And, from the experiment results, the stress-strain relation shows strong dependent on the strain rate. Thus, it is obvious that is needs the viscoplastic constitutive model to describe the mechanical behavior of concrete. In this paper, we start from Ot-tosen' s four parameters constitutive model, considering the performance influenced by damage and strain rate to improve the dynamic contitutive model of the concrete. In the paper, we used the improved Runge-Kutta method to avoid the complication to find the derivatives of complex tensors in the Newton-Raphson iterate method. For integration of time, we use the generalized-method. The method of this paper has better stability and accuracy than other integration method and it provides convenience for further research of this topie.