复合材料结构全信息健康监测方法研究

Composite materials and structures play important roles in extensive applications for various key equipments, including aircraft wings and wind turbine blades. However, damages such as cracks and de-laminations would lead to a catastrophic result on these large scale structures if they are not properly treated in time. Therefore, great attentions and study interests have been put into structural health monitoring in pursuing pivotal solutions in the past decades. This study starts with the forward problem, namely the modeling of structures. In the forward problem study, modeling strategies for composite structures in multi-field coupling condition are firstly investigated. In order to present a more accurate and efficient solution, some special and applicable wavelet finite elements are constructed for the analysis of composite structures, and the modal analysis and wave propagation are conducted via the proposed wavelet finite elements. By aid of the analysis results, the dynamic response mechanism for composite structures in different damage cases is revealed. Following the dynamic response mechanism and analysis results presented by the forward problem investigation, the backward problem, namely the damage identification issue, is studied. In order to overcome the dependence on healthy structures testing data of classical structural health monitoring method, some no-baseline methods are investigated. In order to present an efficient sense principle to the local stress and strain variation caused by damages, some novel stress wave monitoring based methods are investigated in the multi-field coupling condition. Based on the low and mid frequency information given by modal testing and the high frequency given by stress wave monitoring, a holographical health monitoring method among different kinds of sensing information for composite structures is investigated. This study can provide the scientific basis and practical technique for structural health monitoring of composite structures, owing the crucial theoretical significance and widespread application value.

复合材料在包括飞机机翼、风电叶片在内的多类关键机电设备中均有着广泛的应用，但是裂纹、分层等多种损伤形式均有可能对结构造成灾难性的破坏，因此复合材料结构的健康监测受到了极大的关注。本项目首先从正问题建模入手，研究多场耦合作用下复合材料结构建模方法，构造适合复合材料分析的小波有限元单元，实现含损伤结构的模态及应力波分析，揭示复合材料结构在不同损伤作用下的动态响应机理。在此基础上，开展反问题损伤辨识研究，为克服现有方法对健康结构测试数据的依赖，拟研究在无健康数据参考下的模态损伤监测方法；为有效感知局部损伤导致的应力应变变化，研究多场耦合状态下损伤结构应力波监测方法；充分融合反映结构中低频的模态信息与高频的应力波信息及相对应的不同类传感器信息，实现复合材料结构损伤的全信息监测。通过本项研究，可为复合材料结构健康监测提供科学依据及实用技术，具有重要的理论意义和广泛的应用价值。

复合材料结构被广泛应用于航空、航天及其他重要装备中，然而其力学行为复杂，在多场耦合作用下损伤易发且形式多样，需要开展在线监测研究，“横看成岭侧成峰，远近高低各不同”，多样的监测信息为复合材料结构健康监测提供了丰富素材，也为其理性实施带来了巨大阻碍，如何有效利用信息、融合信息是制约复合材料结构健康监测有效实施的一大瓶颈。因此建立高精度数值模型对复合材料结构的多场耦合行为形成准确的先验信息，结合实际监测信号，通过信息融合方法实现全信息结构健康监测，具有重要的学术意义和应用价值。本项目针对以上瓶颈问题，系统地研究了复合材料结构全信息健康监测方法，涉及正问题建模与反问题健康监测两方面。在正问题建模方面，研究了功能梯度、纤维增强两大典型复合材料的小波有限元单元族一般构造方法，构造了多种结构单元及实体单元，丰富了小波单元族；提出了伪并行算法和小波有限元GPU加速算法，降低了求解硬件需求并提升了求解效率；提出了多场耦合分析的交错迭代更新算法，解决了多场耦合问题的数据一致性收敛问题；开展了典型复合材料结构热力耦合、流固耦合问题研究。在反问题层面，结合正问题先验支持，提出了无基线谱曲率模态、伪谱曲率模态方法，解决了传统曲率模态的噪声敏感问题；提出了波数域滤波方法和尺度-波数域滤波方法，有效地抑制了噪声对损伤特征的影响；结合稀疏理论，提出了结构化稀疏方法及稀疏补偿理论等时域稀疏方法，有效地凸显了损伤特征；提出了相空间损伤识别理论，丰富了传统复合材料结构健康监测的内涵；从信息融合角度提出了多变量信息融合及多步法损伤监测，实现了复合材料结构的全信息健康监测。通过以上研究，发表论文23篇，SCI收录18篇，ESI热点论文1篇，ESI高被引论文2篇，EI收录会议论文2篇，EI源刊1篇，会议论文2篇，相关成果申请并获授权发明专利7项。项目主持人担任SCI期刊专辑(IF: 1.239)主编、国际大会分会主席，并获教育部技术发明一等奖1项。