PBX部件机械加工过程中的夹持变形预测

高聚物粘结炸药(PBX)部件机械加工过程中的夹持变形直接影响着炸药部件的加工质量。利用既定的基于修正时间硬化理论的蠕变模型,模拟不同结构PBX部件在不同夹持力下的夹持变形。球壳在真空吸附下型面上各点的变形量随纬度增加而增加,方向与径向呈一定夹角;三爪卡盘夹持PBX部件时,最大变形和最大应力都出现在与卡盘爪子接触的区域,且内型面变形量较外型面略小。与千分尺测PBX空心半球真空吸附下顶点变形的试验数据比较,模型在前20min内具有较高的准确性和可靠性,之后仿真结果大于试验数据,60min内最大误差不超过10%。

Prediction for clamping deformation of PBX parts on machining process

Machining is considered as one of the most important procedures as for complicated components of polymer bonded explosives(PBX).A definitive modified time hardening theoretical creep model was used to predict clamping deformations of different structural PBX parts under various clamping forces,which affects cutting accuracy directly.Simulation of vacuum absorbed spherical shell shows that displacements of points on profile increase with latitude,and its vector has an included angle to radial.When cam-ring chuck gripping a PBX parts,both the maximum deformation and stress appear in the contact area,and the value of internal is smaller than that of the external to a certain extent.Comparing simulation of vacuum absorbed hollow hemisphere with experimental data gauged by micrometer,the creep model has a better accuracy and reliability in the first twenty minutes,and the simulational results larger than test later with a less than 10% extent error within an hour.