高温下混凝土硬化模型研究

高温下混凝土的塑性和粘塑性应变分析是有关水工结构的设计基础本构关系用于表示材料应力和应变之间的联系 ,其中混凝土的硬化模型研究占有重要地位 在硬化模型研究中的难点之一是 ,关键材料参数须由双轴拉压试验方法确定 ,对设备的要求较高 ,工作量大 笔者通过分析材料单元在多轴应力状态和单轴应力状态下变形的内在联系 ,得到了一种由单轴压缩试验确定关键硬化材料参数的简便方法 ,改进了高温下的混凝土本构关系 ,使得进行更为可靠的结构设计成为可能

A Study on the Hardening Model for Concrete under High Temperature

The plastic and visco-plastic strain analysis of concrete under high temperature is the foundation work for the design of related water conservancy structures. The constitutive relation is used to express the relation between the stress and strain of the material. And the study of the hardening model of concrete is of great significance in constitutive relation. One difficulty encountered in the study is that bi axial drawing and compression test is needed to determine the key material parameter, and it calls for more expensive equipment and time consuming work. By analyzing the intrinsic relations between the deformations of a material element under multi axial stress conditions and those under single axial stress conditions this paper presents a simple and convenient method for determining the key material parameter of the hardening model. The method only calls for single axial compression test. In this way the constitutive relation of concrete under high temperature is improved and more credible structure design is available.