多维应力下混凝土开裂相关应力的计算

在钢筋混凝土非线性有限元分析中，混凝土裂缝计算模型常采用片状裂缝模式，以此模式为基础建立的有限元单元中，混凝土开裂后就应考虑到应力的重分布。就应力重分布对一向受拉，两向受压；两向受拉，一向受压；三向受拉；一向受压，两向受拉；两向受压，一向受拉；三向受压等6种情况作了一般性的计算研究。采用幂函数强度准则，用混凝土的本构关系及Kupfer提出的极限应力计算方法结合20结点有限元方法对释放应力进行计算。得出更一般的应力释放的计算方法，此计算模型比简单的应力释放更接近实际。

Calculating Correlative Stress of Concrete Crack in 3-Dimension

In the analysis of nonlinear finite element in reinforced concrete, smeared cracking model is often adopted. In the finite element based on the model redistribution of the stress after concrete crack is considered. Researches on calculation method of redistribution of the stress have been done on six different states. In this paper, intensity rule of power function has been introduced and the redistribution of the stress is calculated. In this process, it is introduced into constitutive relation of concrete, calculation method of limit strain that Kupfer put forward and 20-node finite element method. It acquired a more universally calculation method of redistribution of the stress. Comparing to the simple calculation method redistribution of the stress, this method is much closer to the practical situation and also more accurate.