Buckling of viscoelastic spherical shells
Buckling of viscoelastic spherical shells
复制标题
DOI：
10.1016/j.jmps.2022.105084
复制
发表时间：
2022-10-07
影响因子：
5.3
通讯作者：
Jin, Lihua
中科院分区：
文献类型：
--
作者：
Liu, Tianzhen;Chen, Yuzhen;Jin, Lihua
粘弹性球壳在压力作用下表现出广泛的时间/速率相关的屈曲行为。对于某些载荷，屈曲甚至可能在显著的时间延迟后发生，这称为蠕变屈曲。为了深入了解粘弹性球壳的非线性时变屈曲行为，本文采用小应变中转壳理论和线性粘弹性材料定律相结合的方法建立了球壳的分析模型。给出了具有几何缺陷的轴对称球壳在两种载荷下的数值结果：规定的体积变化率和施加后保持不变的规定压力。第一种类型揭示了粘弹性屈曲的率相关行为，而恒压加载被用来量化蠕变屈曲现象。结果表明，粘弹性和加载速率对壳体的承载行为起着重要的作用，而恒压加载的结果揭示了短时间弹性屈曲极限和长时间蠕变屈曲极限之间的重要联系。构造了恒压载荷下的缺陷敏感图，给出了三种性质不同的区域：近瞬时屈曲、蠕变屈曲和无屈曲。
Viscoelastic spherical shells exhibit a wide range of time/rate-dependent buckling behaviors when subjected to pressure. For certain loadings, buckling can even occur after a significant time delay, termed creep buckling. To gain a thorough understanding of the nonlinear time-dependent buckling behavior of viscoelastic spherical shells, this work develops an analytical model employing the small-strain, moderate-rotation shell theory combined with a linearly viscoelastic material law. Numerical results are presented for axisymmetric spherical shells with geometric imperfections for two types of loading: a prescribed rate of volume change and a prescribed pressure that remains constant after it is applied. The first type reveals the rate-dependent behavior of viscoelastic buckling while the constant pressure loading is used to quantify creep buckling phenomena. The results show that viscoelasticity and loading rates play important roles in the load-carrying behavior of these shells, and the results for the constant pressure loading reveal an unexpected and important connection between the short-time elastic buckling limit and the long-time creep buckling limit. An imperfection sensitivity map is constructed for the constant pressure loading showing three regimes with qualitatively different behaviors: near-instantaneous buckling, creep buckling and no buckling.