多分层对复合材料层合板自振特性的影响

Effect of multiple delaminations on free vibration characteristic for composite laminates

基于Mindlin一阶剪切理论分项等参插值的有限元法,建立了含多个分层损伤复合材料层合板自由振动分析的有限元模型和分析方法,并采用线性接触模型模拟分层区域上、下子板的相互作用。通过典型数值算例,讨论了分层位置、数目及板的边界条件诸参数对其振动特性的影响。结果表明:分层位置沿板长方向变化时,中间分层的频率变化范围较大,表面分层变化较小,但变化趋势基本相同;沿层合板厚度方向,多分层中最长分层的位置越靠近层合板中面,则其对振动特性的影响越大;多个分层位置较靠近层合板表面,且板边界条件约束较弱时,多分层与单分层对振动特性影响的差别不大,此时,可将多分层损伤层合板简化为单分层损伤层合板来进行振动分析。

Based on the first-order shear deformation theory of the composite laminated plate, an FEA model and the method of free vibration analysis for the composite laminates with multiple through- width delarninations were developed, and a linearity contact model was established to simulate the interaction between upper and lower sub-laminates along the delaminated region during the vibration process. The effects of the location and numbers of delamination, and boundary condition of the laminates on the vibration characteristic were discussed. From some typical examples, the results show that, with the variation of delamination location along the length direction, the influence of inner delaminations on frequencies is greater than that of the surface delaminations, but both variation trends are approximate. With the delaminations nearer to the middle plane along the thickness direction, the influence is more severe. When the delaminations are near to the surface and the edges constraints of the laminates are weak, the vibration analysis for the multiple delaminations case can be simplified into that for the one delamination case.