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研究了基体蠕变开裂对黏弹性层合圆柱壳的前屈曲变形特征和分岔蠕变屈曲的影响.采用Schapery的耦合基体开裂的积分型本构关系描述铺设单层的力学行为,由细观力学方法将损伤变量值与基体裂纹密度相关联,并建立基体裂纹密度演化与拉伸应力的幂型关系.基于Donnell型扁壳理论和Kármán-Donnell几何非线性关系得到黏弹性层合圆柱壳在轴向压缩下的前屈曲变形与分岔屈曲控制方程,综合应用有限差分、三角级数展开以及Taylor的卷积积分数值递规算法求解问题.针对多组几何参数、损伤演化参数以及两端边界条件,分析对称铺设玻璃纤维/环氧复合材料圆柱壳在耦合基体蠕变开裂时的分岔蠕变屈曲行为.数值结果表明:基体横向开裂损伤显著降低了短圆柱壳分岔蠕变失稳的临界时间和持久临界荷载,但这种影响随着圆柱壳径厚比的增加而减弱直至消失,对中长圆柱壳,损伤效应与圆柱壳两端的边界条件有关.
The effect of matrix creep cracking on the pre-buckling deformation and bifurcation creep buckling of the viscoelastic laminated cylindrical shell is studied. The integral constitutive relation of Schapery’s coupling matrix cracking is used to describe the mechanical behavior of the single layer, The mechanical method correlates damage value with matrix crack density, and establishes the power-type relationship between matrix crack density evolution and tensile stress.Based on Donnell-type flat-shell theory and Kármán-Donnell geometric nonlinearity relationship, viscoelasticity laminated cylindrical shell Axial compression of pre-buckling and bifurcation buckling control equations, the application of finite difference, trigonometric series expansion and Taylor’s convolution integral numerical method to solve the problem.According to multiple sets of geometric parameters, damage evolution parameters and both ends of the boundary The bifurcation creep buckling behavior of the symmetrically paved glass fiber / epoxy composite cylindrical shell under creep cracking was analyzed. The numerical results show that the transverse cracking of the matrix significantly reduces the creep instability of short cylindrical shell bifurcation Critical time and sustained critical load, but this effect with the increase of the diameter ratio of cylindrical shell weakens until it disappears, the long cylindrical shell The damage effect is related to the boundary conditions at both ends of cylindrical shell.