三维编织物增强复合材料横向冲击频域响应特征

摘要

The dynamic mechanical response of three-dimensional (3-D) braided fabric reinforced composite under transverse impact was tested with modified split Hopkinson bar. The experimental results showed that the peak load increased with the increase of impact velocity. Based on the fracture morphologies of 3-D braided fabric reinforced composites, the failure mode was changed from resin crack to fiber tows breakage with the increase of impact velocity. The frequency-amplitude curve in frequency-domain can be obtained from time-load curve in time-domain by fast Fourier transform (FFT) method. It can be observed from the curve that the impact stress wave mainly concentrated on the low frequency area and the stress wave amplitude increased with the increase of impact velocity.%采用改进型分离式霍普金森杆测试三维编织物增强复合材料在横向(试样厚度方向)冲击加载模式下动态力学响应特征.试验结果表明,最大载荷随冲击速度增加而增加,从试样破坏显微照片中可以得出,随着冲击速度增加,三维编织物增强复合材料失效模式由树脂开裂变为纤维束断裂.采用快速傅里叶变换方法将三维编织物增强复合材料横向冲击时间-载荷曲线转换为频域内频率-振幅曲线,从曲线中可以得出横向冲击应力波频率主要集中于低频区域,且应力波振幅随冲击速度增加而增加.