混凝土拱坝应力分析的有限元方法探讨

Discussion on Finite Element Method of Concrete Arch Dam Stress Analysis

采用有限元法计算拱坝应力时,在拱坝近基础部位存在明显的应力集中,这对计算结果的评价带来了困难。为明确应力集中部位的真实应力水平,以大型分析软件ANSYS为平台,建立了拱坝三维有限元模型。针对同一模型,在相同荷载作用下,分别采用混凝土单轴强度准则(线性有限元法)和混凝土多参数强度准则(非线性有限元法)进行计算,并分析了非线性有限元法计算中参数ft值的敏感性。结果表明,两种方法所得的拱坝应力分布规律基本一致,而非线性有限元法可描述坝体在应力水平较大部位是否开裂。

Using the finite element method to calculate arch dam stress, arch dam foundation appears obvious stress concentration, which causes difficulties of evaluation results. In order to explicit the stress concentration of real stress level, three-dimensional finite element model is established by taking the large-scale analysis software ANSYS as plat- form. For the same model and the same load, stress is calculated by adopting the single axle intensity criterion （linear fi- nite element method） and concrete multi-parameter intensity criterion （nonlinear finite element method）, respectively. And then the sensitivity of parameter ft in nonlinear finite element calculation is analyzed. The result shows that the arch stress distributions of two methods are basically the same while the non-linear finite element method can describe whether the dam is cracking in the part with large stress level.