基于三维梁理论的电磁轨道炮复合身管抗弯性能分析

Analysis of Bending Resistance of Composite Barrel for Electromagnetic Railgun Based on 3D Beam Theory

基于复合材料的三维厚壁梁理论,考虑梁的三维应变、挠曲等效应,建立了圆形电磁轨道炮身管纤维缠绕复合外壳的等效抗弯刚度计算模型。采用组合梁的等效抗弯刚度计算法,对纤维缠绕的轨道炮身管的整体抗弯刚度进行了分析,并与层合板理论法、有限元法做了对比。结果显示,3种计算方法在缠绕角度较大时,计算结果一致性较好。分析了纤维缠绕角度的变化、不同径向位置的碳纤维缠绕角度变化以及不同内膛绝缘材料对身管轴向抗弯刚度的影响。研究结果表明:身管的轴向抗弯刚度在缠绕角度较小时,随着缠绕角度的增大,呈明显的下降趋势,并且其受内层碳纤维的缠绕角度影响要比外层碳纤维的要大;高密度、高弹性模量的内膛绝缘材料并不一定就能提高身管的轴向抗弯刚度。

An estimation model of effective bending stiffness for filament-wound composite housing of cir- cular railgun barrel is established based on the 3D composite material thick beam theory. Some effects of beam, such as the three-dimensional strain and warping, are considered in the proposed model. The cal- culation method of effective bending stiffness of composite beam is used to analyze the bending stiffness of the whole filament-wound composite barrel for railgun. The results are compared with those obtained by laminated plate theory and finite element method. The result shows that the calculated results of the three methods have good consistency for bigger winding angle. The effects of the winding angles of fibers and carbon fibers in different radial positions and the different bore insulators on the bending stiffness of barrel are studied. The research result reveals that the bending stiffness of barrel obviously drops with the in- crease in winding angle while the winding angle is smaller. The winding angle of inner carbon fiber layers has a great effect on the bending stiffness compared with outer carbon fiber layers. The bore insulator with high density and high elastic module can＇t always enhance the bending stiffness of barrel.