进行有限元分析时简支梁约束条件的确定

Determination of constraints for finite element analysis of a simple beam

为使用三维单元对简支梁进行有限元分析,结合简支梁支座的约束特点,提出建立与梁截面中性层重合的基准平面,并用此基准平面与梁的两个端面生成的分割线作为约束对象,对固定铰链端的分割线施加固定约束,对活动铰链端的分割线施加梁端平面内的移动约束的方法,可实现有限元分析中对三维模型的约束功能与材料力学中简支梁的支座约束功能一致.通过与材料力学的计算结果比较可知,这种施加约束的方法,能够获得正确的有限元计算结果,从而为简支梁的有限元分析提供了重要参考.

To do finite element analysis of a simple beam with a three-dimensional element,it is proposed that the reference plane with a neutral layer of the beam cross-section is established,combining with the characteristics of supports for a simple beam.The split lines generated between the reference plane and the two end cross-section of the beam can be taken as a constraint object.A fixed constraint is imposed on the split line ofa fixed hinge end.A moving constraint on the beam cross-section of a movable hinge end is applied to the split line.Thusly,consensus can be achieved on the constraint function of the three-dimensional finite element analysis model and a simple beam based on material mechanics.Comparing with the results from Strength of Materials shows that the correct finite element calculations can be obtained by this method of applying constraints to split lines.An important reference is provided for the finite element analysis of a simple beam.