室温下C/C复合材料紧固件拧紧特性

本文研究了C/C复合材料紧固件在不涂防松胶（简称不涂胶）和涂防松胶（简称涂胶）两种状态下的拧紧特性。试验测试了两种状态下C/C复合材料紧固件拧紧力矩与预紧力的关系，并对两种状态下紧固件摩擦系数和拧紧力矩分配关系进行了深入分析。结果表明:涂胶与不涂胶相比，相同拧紧力矩作用下，螺栓预紧力增大20%~82%，且不涂胶状态下预紧力与拧紧力矩线形关系较好；不涂胶和涂胶两种状态下，螺纹副摩擦系数分别为0.41、0.35，端面摩擦系数分别为0.59、0.41，涂胶后两对摩擦副摩擦系数均降低；另外，涂胶和不涂胶两种状态下施加拧紧力矩在端面摩擦副、螺纹摩擦副和附加力矩中比例分配规则略有不同。 

Tightening torque characteristics of C/C composite threaded fasteners at room temperature

The tightening characteristic of threaded fasteners made of C/C composite under the conditions of no locking adhesive (non-glue coating) and plastering the locking adhesive (glue coating) were investigated. The experiments were done to investigate the correspondence between tightening torques and clamping force of C/C composite threaded fasteners under two conditions, meanwhile, both friction coefficients of thread and bearing-surfaces were analyzed. The results indicate that the clamping force of the glue coating state will be increased by 20%-82% more than that of non-adhesive state under the same tightening torque. Under the glue coating state, the curve of clamping force with tightening torque shows a good linear relationship. And for the non glue coating and glue coating states, the average friction coefficients of thread and bearing-surfaces for the non glue coating bolts are 0.41, 0.35 and 0.59, 0.41, respectively. There is a slight difference between two conditions about the allocation ratio of torque components.