相对刚度对复合材料加筋板后屈曲承载效率影响研究

Effect of Relative Stiffness on Post Buckling Load-Carrying Efficiency of Composite Stiffened Panels

对复合材料加筋壁板后屈曲承载特性进行了研究,建立了复合材料加筋壁板后屈曲非线性分析模型,并引入改进的弧长法模拟加筋壁板后屈曲承载历程,典型加筋壁板轴压试验证明模型分析误差不大于10%。通过筋条和蒙皮变参设计,建立数值分析矩阵,分析结果表明筋条与蒙皮的相对刚度对加筋壁板的后屈曲承载能力及结构效率具有明显影响。筋条相对刚度越大,蒙皮失稳临界点越高,加筋壁板的承载能力和结构效率增高,但当筋条相对刚度超过一定值时,承载能力和结构效率均降低,这在飞机设计中是不能接受的。因此,利用复合材料加筋壁板后屈曲承载能力降低结构重量必须合理确定筋条相对刚度,在保证安全的前提下提高结构效率。

The post buckling behavior of composite stiffened panels is studied.Post buckling nonlinear analysis model of composite stiffened panels and an improved arc length method are introduced into the nonlinear simulation of post buckling loading process of stiffened panels.Axial compression test of typical stiffened panels show that analysis error is less than 10%.Based on the parametric design of stiffeners and skin,the numerical analysis matrix is established.Results show that relative stiffness of stiffeners have obvious effects on post buckling capacity and structural efficiency of stiffened panels.With the increase of relative stiffness of stiffeners,critical point of skin instability become higher,and bearing capacity and structural efficiency of stiffened panels increase.However,when relative stiffness exceeds critical value,bearing capacity and structural efficiency decrease,which is unacceptable and dangerous in aircraft design.Therefore,it is necessary to determine relative stiffness of stiffeners reasonably to reduce the weight of structure by using post buckling capacity of the composite stiffened panels,so as to improve the structural efficiency on the premise of ensuring the structural safety.