考虑间隙配合的复合材料钉载分配均匀化方法

针对多钉连接中因复合材料脆性等因素导致结构中的钉载分配不均匀,以及接头在承载较大的钉位置易发生过早破坏的问题,提出了调整钉孔配合间隙改善钉载分配的不均匀性的优化方法。首先,基于弹簧质量模型,以钉孔间隙为设计变量,建立了多钉连接钉载分配的二次规划优化模型。然后,采用内点法对优化模型进行了求解,得到了优化模型的全局最优解。最后,以复合材料5钉双剪接头为例,对钉孔间隙进行了优化,将计算结果与有限元预测结果进行对比。结果表明:模型优化结果与有限元结果吻合较好,优化后最大钉载比例由41.1%降低到了20%。采用该模型可以高效、准确地实现复合材料多钉连接钉载分配比例的均匀化设计。

Load distribution homogenization method of multi-bolt composite joint with consideration of bolt-hole clearance

Aiming at the quite uneven load distributions in the multiple bolts and premature failure at the most highly loaded induced by the brittle nature of composites, the clearance between the bolt and its corresponding hole was adjusted to improve the unequal load distribution. Firstly, bolt-hole clearances was chosen as the design variable and a quadratic programming optimization model of load distribution for multi-bolt joint based upon spring-mass model was built. Then, the optimization model was solved by using interior point method and the global optimum solution of the optimization model was obtained. At last, as an example, the bolt-hole clearances of composite mechanical joint with 5 bolts were optimized. The calculation results obtained were compared with the prediction results from finite element model. It shows that model optimization results agree well with finite element results. After optimization, the maximum bolt load proportion decrease dramatically from 41.1% to 20%. The model can be used effectively and accurately in uniform design of load distributions for multi-bolt composite joints.