基于振型曲率的夹芯波纹板脱焊损伤分析方法研究

Research on the damage analysis method of sandwich corrugated plate based on modal curvature

针对夹芯波纹板在生产和服役过程中的漏焊、脱焊损伤提出了基于动态响应参数的损伤识别方法。首先基于有限元理论对波纹板不同大小、不同位置的损伤进行数值分析,然后基于数值分析所得损伤前后振动特性参数,使用中心差分法求取结构模态振型曲率,根据求得的损伤前后模态振型曲率,分别用差分法、曲面光滑算法和二维连续小波变换建立损伤识别指标,从而确定损伤的位置和数量。最后通过数值分析和实验数据处理,验证了损伤分析方法的有效性和可靠性。计算结果表明:基于模态振型曲率建立损伤识别指标的差分法、曲面光滑算法以及二维连续小波变换均可以检测到损伤的位置和数量,但曲面光滑算法和二维连续小波变换相较于差分法不需要结构损伤前的原始数据,更适用于工程实际问题。

A damage identification method based on dynamic response parameters was proposed for the missing welding and debonding damage of sandwich corrugated plate caused during production and service.First,based on the finite element theory,the damage of the corrugated plate in different sizes and positions was numerically analyzed.Then,based on the vibration characteristic parameters before and after the damage obtained by numerical analysis,the modal curvature of the structure was obtained by using the central difference method.According to the obtained modal curvature before and after the damage,the damage identification index was established by difference method,gapped smoothing method and two-dimensional continuous wavelet transform respectively to determine the location and quantity of damage.Finally,through numerical analysis and experimental data processing,the validity and reliability of the damage analysis method are verified.Calculation results show that the difference method,gapped smoothing method and two-dimensional continuous wavelet transform based on modal curvature can detect the location and quantity of damage.However,compared with the difference method,the gapped smoothing method and the two-dimensional continuous wavelet transform do not need the original data before damage,and are more suitable for practical engineering problems.