基于热力学定律的混凝土本构模型研究

CONSTUTIVE RELATIONSHIP OF CONCRETE BASED ON THERMODYNAMICS

由热力学定律出发,介绍了耗散函数的形式,给出了建立混凝土本构模型的方法和过程,并对参数的确定进行了讨论,得到了基于热力学原理的混凝土多轴本构关系和真实应力空间中的屈服准则、破坏准则及塑性流动法则。由此方法建立本构模型,引入假定较少,避免了假设"塑性势函数"的做法,得到的结果自动符合热力学原理,具有一定的普遍性。算例表明,该模型计算结果与试验结果符合较好。

Starting from thermodynamics, a form of energy dissipation function is introduced, a method of establishing constitutive model of concrete is proposed, and parameters of the model are discussed. Eventually a concrete multi-axial constitutive relationship, yield criterion, failure criterion and plastic flow rule in actual stress space based on thermodynamics are derived. The method invokes fewer hypotheses and avoids supposing a plastic potential function. The obtained model accords with thermodynamics naturally, and is universally valid. Numerical simulation is in conformity with experiments.