复合材料表面处理状态对机械连接结构预紧力的影响研究

Study on Pre-tension Load in the Composite Bolted Joint Structures with Different Surface Finishes

机械连接结构由于其优异的可靠性被广泛应用于复合材料结构连接中,被连接结构由于其位置、功能等各方面的要求不同,会有各种不同的表面处理状态,本文通过试验方法给出了复合材料结构表面处理状态对连接结构预紧力的影响。基于螺纹紧固模拟装配分析系统,对13组不同表面处理状态的试验件在相同紧固件类型、相同紧固力矩和紧固转速下的预紧力进行了测试。试验结果表明,泰德拉铺层和底漆对预紧力影响较大,无论是在贴模面还是贴袋面增加泰德拉铺层,都会使预紧力显著增大,同样,底漆会使预紧力显著降低,另外,连接结构的等效摩擦系数包括螺纹摩擦系数和接触表面摩擦系数也相应地变化。

Bolted joint is commonly used on carbon fiber reinforced composite structures.There are different surface finishes for the bolted structures according to sealing,anti-corrosion,lightning protection requirements.The influence of the surface finish of bolted structures on the pre-tension load of the bolt was studied experimentally.Based on a Analyse test simulation system,the pre-tension loads of 13 groups of specimens with different surface finishes,under the same fastener type,tightening speed and tightening torque,have been measured.Accordingly,the friction coefficients of bearing surface and thread have been calculated.The experimental results show that Tedlar coating and primer have significant effects on pre-tension load.The pre-tension load of the specimens with Tedlar-coated surface is larger than those with Primer-coated specimens.In addition,the thread friction coefficient and the contact surface friction coefficient are accordingly changed.