某型机箱冷板紧固件失效分析

Failure Analysis of Bolt in Cold Plate of an Airborne Chassis

针对某机载机箱冷板紧固件的断裂问题,在Hyper Mesh中建立有限元模型,利用Ansys进行动力学仿真分析,将试验中测取的加速度功率谱密度曲线与对应计算值进行比较,验证有限元模型的合理性。通过计算得到每个螺钉分配的载荷,根据所用螺钉的等级进行剪切强度校核,确定螺钉断裂是由于螺钉剪切强度不足引起的。根据计算结果提出了更改措施,并通过了试验的考核。

In this paper, aiming at the breakage of bolt in cold plate of an airborne cabinet, the finite element model is estab-lished in the HyperMesh, and the random vibration analysis is performed by using the Ansys. The acceleration power spectral density curve of the particular points which is measured in vibration test is compared with the corresponding simulation value to insure the validity of the model. The shear loads of the bolts are calculated, the shear strength check is done according to the bolt grade, and the result shows that the breakage happens because the maximum shear stress is beyond the shear capacity. This problem is then solved by using higher-grade and larger-diameter bolts.