复合材料壁板中长桁的胶接应力分析

Analysis of adhesive stresses of stiffeners in stiffened composite panels

用拟协调板元和梁元离散飞机尾翼翼面典型复合材料加筋壁板,对长桁截面刚度突变和面板后屈曲剧烈变形两种导致脱胶情况分别进行了线性前屈曲和非线性后屈曲逐渐破坏有限元分析,利用文中提出的节点力法,计算长桁与面板间的胶接应力。结果表明:刚度突变在突变处引起相当大和逐渐衰减的胶接应力,剪应力的衰减比正应力慢;后屈曲变形的急剧变化导致与波峰和波谷对应的胶接点的胶接应力比较高,但低于两倍临界载荷时,胶接应力不大。

A finite element analysis of linear prebuckling and postbuckling with progressive failure for composite stiffened panels, as typical components of wings or empennages, was carried out using a quasi-conforming laminated plate element and beam element. According to a proposed method to calculate adhesive stresses by using node forces, the adhesive stresses between stiffeners and skin were computed in two typical cases： stiffener stiffness jump and postbuckling progressive failure. The numerical results show that the stiffness jump may cause considerably large and progressively attenuated stresses of adhesion in the vicinity of the jump points and the attenuation of shear stresses is slower than that of normal stresses. The rapid variation of postbuckling deformation in panels leads to higher adhesive shear stresses at wave peak or valley. But the adhesive stresses are not large if the load is lower than twice of critical load.