缠绕复合材料壳体低速冲击后剩余强度影响因素分析

A Parameter Study of Residual Strength of Filament Wound Composite Shell after Low-Velocity Impact

关键词:  缠绕复合材料壳体  低速冲击  剩余强度  冲击部位  初始内压  冲头尺寸

Key words:  Filament wound composite shell  Low-velocity impact  Residual strength  Impact location  Initial internal pressure  Impactor size

摘要:

为探索不同因素对缠绕复合材料壳体低速冲击后剩余强度的影响规律，开展了不同冲击能量、不同冲击部位下壳体的低速落锤试验和水压爆破试验，采用改进的Hashin准则和牵引分离准则模拟复合材料层内和层间损伤，建立了壳体冲击后剩余强度有限元模型，实现了冲击后剩余强度的一体化仿真分析。利用该模型计算得到的缠绕复合材料壳体低速冲击后剩余强度与试验结果一致性较好。最后研究了冲击部位、初始内压、冲头尺寸等因素对壳体冲击后剩余强度的影响规律。研究结果表明:封头赤道圆处为壳体的最薄弱冲击部位，冲击能量为25J时壳体剩余强度降低了约60%；壳体冲击后剩余强度随内压增加而增大，但当内压大于16MPa时，壳体冲击后剩余强度随内压增大而迅速降低；冲头直径在8～16mm变化时，壳体冲击后剩余强度随着冲头直径的减小而降低。

Abstract:

In order to study the effects of different factors on the residual strength of filament wound composite shell after low velocity impact， drop-weight and water burst tests were carried out on the shell with different energy levels and different impact locations. Modified Hashin criterion and traction separation criterion were used to simulate the intralaminar damage and interlaminar damage， respectively. A finite element model was established for residual strength analysis of shell after impact. The requirement of integrated residual strength analysis after low-velocity impact was realized. The residual strengths after low-velocity impact of filament wound composite shell obtained from this model were well agreed with the experimental results. Then， the model was used to study the effects of impact location， initial internal pressure and impactor size on the residual strength of shell. Research results show that the most serious impact location is at the equator circle of dome. When the impact energy is 25J， the residual strength of shell after impact at this location is reduced about 60%. The residual strength of shell is increasing with the internal pressure added， while the residual strength will be reduced when the internal pressure is greater than 16MPa. The residual strength of shell will be decreased with the reduction of the impactor diameter when it is changed between 8mm and 16mm.