飞行器典型结构的热适配分体螺栓连接技术

由于复合材料与高温合金的热膨胀系数差异，导致在高温环境下采用高温合金机械连接件的复合材料组合构件发生预紧力降低。为解决高超声速飞行器热部件的连接难点、保证热结构的高温可靠性，对复合材料部件与高温合金螺栓的连接进行了研究。对一种采用分体式热适配螺栓的方法进行了相关的理论推导，采用典型单元进行的数值模型仿真表明了结果趋势的一致性良好。采用C/SiC局部端框的典型试验表明，这种新的连接设计在不改变以往常规连接强度性能的情况下，可以将820℃条件下的高温剩余预紧力由大约14%有效提升至80%。

Connection technique for thermal adaptive bolts with split-piece design in typical vehicle structures

The pre-tightening axial force of combined composite parts connected mechanically by high-temperature alloy bolts will be reduced in high temperature environments because of different thermal expansion coefficients between composite materials and high-temperature alloys. To overcome the difficulty of connection for hypersonic vehicles and ensure the reliability of thermal structures in high temperature environments, the connection between composite material parts and high-temperature alloy bolts is investigated in this paper. The theoretical formula of a certain type of thermal adaptive bolt with split-piece design is derived, and the consistent result is obtained by numerical model simulation. It is proved, by the typical partial end-frame test, that the residual pre-tightening axial force at high temperature can be improved effectively from about 14% to 80% at 820 ℃, under the condition that the mechanical connection strength of this new design method is the same as that of the former ordinary connection.