沥青混凝土局部应变模型及其数值分析

论述了沥青混凝土材料由于应力、加载时间及温度变化所引起的应变局部化问题,在动态塑性理论的基础上,提出了相关连续动态塑性理论模型以及模拟沥青混凝土材料变形破坏的新方法,并编制了相应的有限元程序·用该模型模拟分析了沥青混凝土(典型的相关率材料)受力破坏过程·由于模型考虑了应变率的相关性,模型具有非网格依赖性·对半弯曲模型的数值试验(SCB)结果表明沥青混凝土(典型的应变相关率材料)破坏过程中存在着应变局部化问题·模型能较好地模拟局部破坏的形成过程·

Modeling of Strain Localization in Asphaltic Concrete and Numerical Analysis

Finite element strain localization analyses of strain rate, history and temperature dependent material like asphaltic concrete were conducted. The theory of rate-dependent consistent plasticity was chosen as the most suitable material for constitutive framework in modeling the nonlinear response of rate-dependent material. With this model, mesh sensitivity issue for strain localization simulation was demonstrated by means of one-dimensional bar compression test. The asphaltic concrete, as a typical rate-dependent material, was chosen for the finite element analysis. A one-dimensional asphalt concrete bar subjected to dynamic compression load with different numbers of elements was examined. It was found that the independence due to the strain-rate-dependent characteristics within the model mesh can be ensured. The contribution of the model on the formation of localization within the semi-circular bending (SCB) test is presented in detail.