碾压混凝土温度场分析中层面模拟的复合单元法

COMPOSITE ELEMENT METHOD OF LIFT JOINT SIMULATION FOR ROLLER COMPACTED CONCRETE TEMPERATURE FIELD ANALYSIS

碾压混凝土层面的模拟是温度场仿真分析中的难点。基于复合单元法的基本原理,建立针对碾压混凝土(RCC)温度场分析的复合单元模型。该模型前处理简便快捷,层面含于复合单元之中,划分网格时不予考虑,使网格的生成大大简化,减少了计算模型的规模。复合单元中可含有由层面分割而成的任意形状的子单元,每个子单元各有一组用于插值的映射节点温度,而层面上的温度值则由其相邻的2个子单元的映射结点温度计算得到。复合单元中映射子单元的结点温度求解过程与传统有限元法类似,不含层面的单元自动退化为常规有限单元,因而复合单元法计算程序可以方便地与传统有限元分析程序融合,简单模型算例验证了该算法的正确性。

The lift joint segments which distribute in the roller compacted concrete(RCC) are difficult to be simulated in the temperature field analysis. Based on the principle of composite element method(CEM),the composite element model for temperature field of RCC is built. The preprocessor is simple and convenient and the lift joint segments are contained in the composite elements,thus the mesh generation of lift joint can be considerably simplified. The quantity of mesh can be easily controlled and the shape of mesh can be improved. The composite elements may contain sub-elements of arbitrary shape whose temperature can be interpolated from their corresponding mapped nodal temperatures. The temperatures in lift joint segments are calculated from mapped nodal temperatures of their neighboring sub-elements. In composite element method,the solving procedure of the mapped nodal temperatures is similar to that in conventional finite element method,and the elements containing no lift joint are degenerated to conventional finite elements automatically. The programs for composite element algorithm can be incorporated into the conventional finite element analysis procedure with intrinsic coherence. The comparative study between the composite element method and the conventional finite element method has been illustrated to verify the composite element algorithm for temperature of RCC.