管板有限元分析模型与对比

Models of the Finite Element Analysis of Tube Sheets and Their Comparison

利用多孔板的当量实心板理论,建立了3种管板有限元分析的简化模型:分别将管束简化为弹性基础(模型Ⅰ);与实际管子数量相同的杆(模型Ⅱ);与管束具有相同金属横截面积的若干等厚度同心圆柱壳(模型Ⅲ)。通过典型算例,将这3种简化模型的位移及应力强度计算结果与直接将结构离散化模型(模型Ⅳ)进行对比。结果表明,模型Ⅰ和模型Ⅲ在管板布管区内部具有良好的精度,而模型Ⅱ精度较差。所有3个简化模型在管板布管边缘区均会得到保守解;而在管板的布管区之外及扳边区域,这些模型均具有良好的精度。

A simplified model of the finite element analysis of three kinds of tube sheets was founded using the equivalent solid plate theory of multi-perforated plates. The tubebundle was simplified into elastic foundation（ Model Ⅰ）, bars with the same number of actual tubes（ Model Ⅱ）, and several concentric cylinders of equal thickness and equal metal cross-section area with the tube bundle（ Model Ⅲ）. The displacements and calculation results of stress strength of the three simplified models were compared with the discretization model whose structure was directly dispersed （Model Ⅳ）. The result shows that Model Ⅰand Model Ⅲ have satisfied precision inside the perforated region of the tube sheets, the precision of Model Ⅱ is comparatively poor. The conservative solution must be obtained by all the three simplified models in the circumference of the perforated region of tube sheets. All the three models are accurate in the knuckle and imperforated regions.