非标准交接板梁组合结构的有限元建模新方法

A New Finite Element Model for Plate-Beam Combined Structures with Non-standard Connection

讨论了两类比较特殊的非标准交接板梁组合结构——有相当横截面面积的筒形壳 /管形状的梁与板壳单元的组合结构 ,指出了对这些组合结构的常规处理方法可能导致板壳单元对梁单元变形约束的放松 ,造成约束刚度的低估和相应特征频率计算结果偏低的虚伪现象 .利用 MSC/NASTRAN结构有限元分析软件中的多点约束 ( MPC)法 ,提出了一种新的建模方法 ,可以很好地解决上述问题 .

Two special kinds of plate beam combined structures with non standard connection, that is the barrel shaped beam with a large dimension of cross section connected with the plates, were discussed. By analyzing several traditional methods for simulating these structures, it is found that those methods in fact loosen the constraints of the beams supported by the plates to some extent and underestimate some constraint stiffness, resulting in deviation of the mode results. By using the MPC method, one specific feature of MSC/NASTRAN, a new finite element model was presented, which can solve the problems effectively. Two examples of this work were given. The numerical results show that the new modal is valid.