低速冲击载荷下C/C-PMI夹芯板动态响应数值分析

Numerical analysis of the dynamic response of C/C-PMI sandwich panels under low-velocity impact loading

  • 摘要: 【目的】为揭示C/C编织层合板与PMI泡沫组成的夹芯结构在低速冲击载荷下的动态响应及损伤演化机理,明确冲击能量及关键结构参数对结构力学性能的影响规律。【方法】构建了耦合VUMAT复合材料渐进损伤与考虑应变率效应的PMI泡沫可压缩塑性有限元模型。针对低速冲击载荷下夹芯板结构的动态响应展开系统的研究,并定量分析是否考虑泡沫芯材应变率效应对结果的影响。进一步针对夹芯板的关键结构参数开展敏感性分析。【结果】不考虑应变率效应将严重低估估夹芯结构的动态承载能力。C/C-PMI夹芯板的主要破坏机制为基体拉伸,基体压缩和泡沫芯层的压溃损伤,其中PMI芯层的塑性压溃是结构主要的能量耗散途径,其吸能占比达到83.2%。随着冲击能量增加,局部失效的范围变大导致能量吸收效率的降低。芯层比是影响结构抗冲击响应的主要参数,随着芯层比的增加,结构吸能效率提升,但过高的芯层比会导致面板过早穿透,引发芯层局部化压溃,不利于整体承载。【结论】该研究解释了动态冲击响应下考虑应变率效应的夹芯板的结构响应特性,为该复合材料舰船的抗低速冲击强度设计与安全性评估提供了一定的参考。

     

    Abstract: Objectives This study aims to reveal the dynamic response and damage evolution mechanisms of sandwich structures composed of woven C/C laminates and PMI foam under low-velocity impact loading, and to clarify the influence of impact energy and key structural parameters on their mechanical performance. Methods A numerical simulation model was established, incorporating a progressive damage model for the composite laminates implemented via a VUMAT subroutine and a crushable foam plasticity model for the PMI foam considering strain rate effects. A systematic investigation was conducted on the dynamic response of the sandwich panels under low-velocity impact, quantitatively analyzing the influence of the foam core's strain rate effect on the simulation results. Furthermore, a sensitivity analysis was performed on the key structural parameters of the sandwich panel. Results The results indicate that neglecting the strain rate effect severely underestimates the dynamic load-carrying capacity of the sandwich structure. The primary failure mechanisms of the C/C-PMI sandwich panels include matrix tension, matrix compression, and foam core crushing. The plastic crushing of the PMI core acts as the primary pathway for energy dissipation, accounting for 83.2% of the total energy absorption. As impact energy increases, the expansion of localized failure leads to a decrease in energy absorption efficiency. The core-to-face sheet thickness ratio is identified as the primary parameter affecting the impact response; while increasing this ratio enhances energy absorption efficiency, an excessively high ratio leads to premature face sheet penetration and localized core crushing, which is detrimental to the overall load-bearing capacity.Conclusions This study elucidates the structural response characteristics of sandwich panels considering strain rate effects under dynamic impact, providing a valuable reference for the low-velocity impact resistance design and safety assessment of such composite structures in naval engineering applications.

     

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