黏弹性层合圆柱壳的蠕变分岔屈曲  

BIFURCATION CREEP BUCKLING OF VISCOELASTIC LAMINATED CIRCULAR CYLINDRICAL SHELLS

作　　者：彭凡[1] 向红[1] 傅衣铭[1] 

机构地区：[1]湖南大学力学与航空航天学院,长沙410082

出　　处：《力学学报》2006年第6期792-798,共7页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(10572049);湖南省自然科学基金(05JJ30008)资助项目.~~

摘　　要：采用Boltzmann积分型本构关系描述铺设单层的黏弹性力学行为,基于DMV扁壳假定和Kármán- Donnell几何非线性关系,研究了对称铺设黏弹性层合圆柱壳的前屈曲变形特征和分岔蠕变屈曲．对玻璃纤维/环氧树脂基复合材料层合圆柱壳的分析结果表明,在前屈曲阶段,挠曲变形和环向薄膜力随时间的变化趋势主要取决于圆柱壳的铺设方式,可以呈现完全相反的变化特征；层合短圆柱壳两端的边界条件对其蠕变分岔屈曲行为有决定性的影响,径厚比的增加将使分岔形式的延迟失稳现象更加明显．The prebuckling creep deformation and bifurcation creep buckling for viscoelastic symmetrically laminated circular cylindrical shells subjected to axial compression are analyzed. Boltzmann hereditary constitutive relationship is used to model the viscoelastic behavior of lamina and the instantaneous elastic response is assumed when bifurcation occurs. The governing equations of prebuckling creep deformation and bifurcation buckling are based on DMV shallow shell theory and the Kármán-Donnell geometrically nonlinear relationship The numerical procedure and analytical deduction based on viscoelastic approach and quasi-elastic approach, respectively, are performed to investigate the behavior of prebuckling creep deformation. A semi-analytical solution strategy is adopted to obtain the critical time of bifurcation buckling. Particular attention is placed on the analysis of glass/epoxy matrix composite circular cylindrical shells, results of prebuckling creep deformation show that the time-dependent evolution of flexural deformation and circumferential membrane force is strongly dependent on the lay-up configuration of cylindrical shells. Both of them decrease in the case of cross-ply conditions and increase for symmetric angle lay-up mode with time. The boundary condition at two ends of short laminated cylindrical shells with symmetric angle lay-up plays a key role on the stability and the bifurcation creep buckling may not be observed for simply supported ends. The increase of the ratio of radius to thickness will deteriorate the long term stability of laminated cylindrical shells with constrained ends.

关 键 词：黏弹性 层合圆柱壳 前屈曲 分岔屈曲 铺设方式 

分 类 号：O344.6[理学—固体力学]