层合板多螺钉单剪连接钉载分配的试验研究

Experimental Study of Load Distribution in Single-lap, Multi-bolt Composite Joints

钉载分配是预测复材多钉连接强度和整体结构失效的关键,采用应变片测量间接获得了三钉单剪连接钉载分配比例,测量了单钉单剪连接的载荷-位移曲线和极限摩擦力,分析了钉载分配的影响因素。研究结果表明:相同条件下,首、尾钉载比例接近相同,约为36%,两者偏差<1%;钉-孔间隙影响最明显,拧紧力矩影响较大,夹紧面积影响较小。

The load distribution is mainly used to predict the strength and failure of multi-bolt composite joints.The ratio of nail load distribution of three-nail single-shear connection is obtained indirectly by strain gauge measurement.The load-displacement curves of single-bolt,single-lap joint and critical friction forces are measured for researching on the influencing factors of the pin load distribution on the single-bolt,single-lap composite joints.The results show that under the same condition,the pin load ratio of the first and the last bolt is close to the same,about 36%,and the deviation ratio is<1%;the effect of bolt-hole clearance on the load distribution is the most obvious,followed by bolt-torque,and the washer size has less influence.