初始缺陷对加筋板结构极限强度的影响研究

采用非线性有限元软件Ansys研究包含3种初始缺陷加筋板结构在单轴压缩载荷作用下极限强度的变化趋势,即初始变形、残余应力和凹陷.以单筋单跨加筋板模型为研究对象,考虑初始变形,不同半径及不同速度的撞击球所形成的凹陷及残余应力对加筋板极限强度的影响.结果表明,初始缺陷的存在降低了结构的极限承载力,而且缺陷的叠加作用比单独缺陷存在时对结构极限强度的影响大;加筋板的极限强度随着凹陷深度的加深而减小;3种初始缺陷中,残余应力相对于初始变形和凹陷对结构极限强度的削弱影响更大.

Effect of initial imperfections on the ultimate strength of stiffened panels

The ultimate strength of stiffened panel with three initial imperfections under uniaxial compression loading by the nonlinear finite element software ANSYS. Three initial imperfections, namely, initial deformation, dent is assumed to formed by the ball with different radius and different speed impacting on the stiffened plate and residual stress. One stiffened panel is introduced, the effect of three imperfections on the ultimate strength of stiffened panels. It is indicated that initial im-perfections reduce the ultimate strength of stiffened panel, the effect of superposition of imperfections to ultimate strength i greater than that of only one imperfection to ultimate strength. Ultimate strength of stiffened panel decreases with the in-crease the depth of dent. Compared to initial deformation and dent, the reduction of residual stress to ultimate strength is greatest.