单剪螺栓连接复合材料叠层板螺栓孔周边应力场分布

基于螺栓连接三维实体模型，研究螺栓-孔间隙、挤压面摩擦因数等因素对挤压面上的应力分布的影响。研究发现螺栓连接叠层板每层中在纤维方向上释向应力和周向应力达到最大值，单层板铺层方向是径向应力和周向应力的主要承载方向。螺栓-孔间隙对孔周应力的分布产生较大的影响，径向应力分布具有相似性，间隙越大，径向应力水平越高，最大周向应力反而有所减小，而且间隙的存在使得径向应力的分布发生改变，最大径向应力向外加载荷方向靠近；螺栓-孔接触面的粗糙程度对孔周应力的分布也产生较大的影响。随着摩擦因数的增大，最大径向应力随之减小；最大周向应力随着摩擦因数的增大而减小。

STRESS DISTRIBUTION AROUND THE BOLTHOLE IN THE BOLT-LOADED LAMINATE

Based on the three-dimensional model, the effects of bolt-hole clearance and friction coefficient on the stress field around the bolt hole in the bolt-loaded laminate has been studied. The research results showed that the maximum radial stress and the maximum tangential stress occur in the position where the angle is consistent with the lay-up of the local ply. So the fiber longitude direction coincides with the main load direction in every ply. The bolt-hole clearance affects the stress distribution around the bolthole greatly, and the radial stress distribution resembles each other for different bolt-hole clearance level. With the clearance increasing, the radial stress level increases; the maximum tangential stress decreases in some extent. Since the clearance exists, the radial stress distribution changes, the position of the maximum radial stress moves to the net bear direction. The friction coefficient in the contact area affects the stress distribution around the bolthole. With the friction coefficient increasing, the maximum radial stress decreases; and so is the maximum tangential stress.