This paper is concerned with the effect of variation in temperature and moisture concentration on free vibration response of skew laminated hybrid composite and sandwich plates. The coupled thermo-elastic and hygro-elastic finite element model is formulated using the first-order shear deformation theory (FSDT). Uniform temperature and moisture concentration rise is considered for the analysis. Soft-core viscoelastic materials are considered for the sandwich plates and are modeled using the complex modulus approach. Linear strain-displacement relations are used to develop a mechanical stiffness matrix, and the initial stress stiffness matrix is generated using non-linear strain-displacement relations to represent the non-mechanical stiffness matrix. Numerical examples for the generated finite element model are presented and discussed comprehensively to understand the effect of temperature, moisture concentration, skew angle, length to width ratio, length to thickness ratio, and boundary conditions on the vibration response of the laminated hybrid composite and sandwich plates. Further investigation is devoted to studying the influence of temperature and moisture concentration-dependent material properties, stacking sequence, core to face sheet thickness ratio, and fiber orientation on vibration behavioral response of sandwich and hybrid composite plates.

本文关注温度和水分含量的变化对斜层压复合材料和夹心板自由振动响应的影响。利用一阶剪切变形理论（FSDT）建立了热弹与湿弹耦合的有限元模型。分析时考虑温度和水分浓度的均匀上升。夹层板考虑使用软核粘弹性材料，并使用复数模量方法进行建模。线性应变-位移关系用于建立机械刚度矩阵，并使用非线性应变-位移关系生成初始应力刚度矩阵，以表示非机械刚度矩阵。给出了生成的有限元模型的数值示例，并进行了全面讨论，以了解温度，水分浓度，偏斜角，长宽比，长厚比以及边界条件对层压复合材料和夹层板振动响应的影响盘子。进一步的研究致力于研究与温度和湿度有关的材料特性，堆垛顺序，芯与面板厚度比以及纤维取向对夹芯复合板和混合复合板振动行为响应的影响。