Development of Advanced Techniques in Structural Health Monitoring and Enhancement

发展基于振动分析的结构健康监测新技术，提高结构健康监测的灵敏度，利用智能材料实现有效的结构修复和加固，以提高各种机械工程结构（如地面车辆和飞机中的梁、板、架等）的可靠性和耐久性。首先，基于振动分析的损伤检测的灵敏度将通过开发和应用新的数据分析方法和具有主动控制过程的新的振动分析技术来增加。这些方法可以更有效地检测疲劳裂纹的发生和扩展，并评估损伤程度。其次，利用高分辨率激光传感器和空间小波分析对板架结构的损伤（如裂缝和节点松动）进行定位。此外，通过上述监测技术了解各种类型损坏的发生、发展和位置，将开发新的结构修复和增强过程，以提高和延长结构可靠性和使用寿命。将应用与压电叠层和/或纤维耦合的新致动器，以在损伤部位提供激励，从而减少应力集中。将研究新型压电致动器的不同安装和控制方法，以实现有效的修复和增强过程，以适应可变的工作和负载条件。

Novel techniques will be developed to increase the sensitivity of structural health monitoring based on the vibration analysis and achieve the effective structural repair and enhancement by using smart materials so as to improve reliability and durability of various mechanical engineering structures (e.g. beams, plates and frames in ground vehicles and aircraft). First, sensitivity of the damage detection based on the vibration analysis will be increased by developing and applying new data analysis methods and novel vibration analysis techniques with active control process. These methods can detect the occurrence and growth of the fatigue crack more efficiently and evaluate the damage extent. Second, damages (e.g. crack and loose of joints) on plate and frame structures will be located by using high resolution laser sensors and spatial wavelet analysis. In addition, with the knowledge of occurrence, growth and location of various types of damage from the aforementioned monitoring techniques, new structural repair and enhancement processes will be developed to improve and extend the structural reliability and serving life. New actuators coupled with piezoelectric stacks and/or fibers will be applied to provide excitation at the site(s) of damage to reduce the stress concentration. Different mounting and control methods of the new piezoelectric actuators will be studied to realize efficient repair and enhancement processes that can fit the variable working and loading conditions.