16自由度的中厚板弯曲矩形单元

基于有限条带思想,引入结点扭率自由度,利用深梁单元的位移模式建立了一个4结点16自由度中厚板弯曲高阶单元,此单元是薄板单元BFS-16的推广形式,其特点是单元的横向位移、转角位移、剪应变位移模式直接构造,在边界上位移模式与深梁单元一致,方便与梁单元叠加,适应于带加劲肋的板弯曲问题分析,用于薄壁结构时可考虑翘曲。实例计算显示,此单元精度高,计算稳定,收敛快,无剪切闭锁现象,能较好地反映中厚板的边界效应。

16 DOF Bending Rectangular Element for Mindlin-Reissner Plate

Based on the scheme of finite belt and interpolating function of deep beam element,a four-node-16-degree of freedom element is presented,which is the extending formulation of BFS-16 element for thick plate with the ratio of wresting DOF,and charactered by direct construction of transverse displacement,rotating displacement,curvature and shear strain and the interpolating function at the boundary gets identical to the deep beam element.The element can be overlapped with beam,especially for reinforced ribs and thin-wall structures with warping.Numerical computations confirm the high accuracy,stability and quick convergence.The element free from shear lock is effient to reflect the boundary effects of Mindlin-Reissner plates.