夹芯复合材料损伤分析方法研究

Study on damage analysis method of new sandwich composite material

为了实现夹芯波纹板在加工和服役过程中由于冲击载荷、疲劳等产生的脱焊损伤缺陷无损伤检测,本文提出一种对损伤进行定量识别的检测方法,基于动态响应参数对夹芯波纹板结构开展损伤分析方法研究。根据固有频率、模态振型、振型曲率、模态应变能等参数理论,建立夹芯波纹板有限元模型,基于动态响应参数开发曲面光滑算法、曲率模态变化率法和二维连续小波变换法对结构脱焊损伤进行识别;然后对该模型进行模态分析,获取损伤夹芯波纹板模态振型,使用中心差分法求取模态振型曲率,将模态振型曲率作为损伤敏感参数,通过提出的损伤检测方法对该敏感参数进行处理,分别建立损伤识别指标,对损伤的位置、数量进行识别,并对各方法损伤识别结果进行对比分析。结果表明,曲率模态变化率法和二维连续小波变换法可有效识别出损伤的位置和数量,且曲率模态变化率法的损伤识别指标更显著,损伤识别效果最好。但在预设一处损伤的情况下,曲面光滑算法还需进一步研究和验证。

In order to achieve non-destructive detection of delamination defects caused by impact loads and fatigue during the processing and service of sandwich corrugated plates,a detection method for quantitative identification of damage was proposed based on dynamic response parameters,and a damage analysis method for sandwich corrugated plate structures was studied.According to the theory of natural frequency,modal shape,modal curvature,modal strain energy and other parameters,the finite element models of sandwich corrugated plate were established.Based on the dynamic response parameters,the surface smoothing algorithm,curvature modal change rate method and two-dimensional continuous wavelet transform method were developed to identify the structural debonding defects.Then,modal analysis was conducted on the model to obtain the modal shape of the damaged sandwich corrugated plate.The central difference method was used to obtain the modal curvature,which was used as a damage sensitive parameter.The proposed damage detection methods were used to process the sensitive parameter,establish damage identification indicators,identify the location and quantity of damage,compare and analyze the damage identification results of each method.The results showed that the curvature mode change rate method and the two-dimensional continuous wavelet transform method can effectively identify the location and quantity of defects,and the curvature mode change rate method had more significant damage identification indicators,with the best damage identification effect.However,in the case of one preset damage,the surface smoothing algorithm needed further research and verification.