Lamb Wave Sensors for Inspecting Civil Infrastructures

9523349 Kundu超声波技术已被发现在检测相对小的样品中的小缺陷方面非常有效。 然而，在大型民用基础设施类型的样本，如桥梁，柱，杆和管道的超声波技术的使用受到限制，因为高吸收和散射的体波（纵波和横波，用于超声波实验）在这样的大对象。 在该项目中，非常规的低频兰姆波（30 kHz - 200 kHz）将用于检测民用基础设施的内部缺陷。初步研究表明，对于检测弱键和部分受损的内部界面，兰姆波比体波更有效。 然而，兰姆波传感器还没有开发出它的全部潜力，因为在传感器行业缺乏在这一领域的专业知识。 在这项研究中，开发有效的兰姆波或导波传感器所需的理论将首先开发。 然后在传感器制造业的帮助下制造新的传感器。 这些传感器将在赖特帕特森材料实验室进行测试，并将用于检测混凝土和金属板以及管道型民用基础设施的内部损坏。 为开展上述研究，资助了两个配套项目：亚利桑那大学将开发基本兰姆波理论并进行初步传感器设计和测试，代顿大学/赖特帕特森实验室将测试制造的传感器并评估结果。 ***

9523349 Kundu Ultrasonic techniques have been found to be very effective in detecting small defects in comparatively small samples. However, in big civil infrastructure type specimens such as bridges, columns, poles and pipelines use of ultrasonic techniques has been limited because of high absorption and scattering of body waves (longitudinal and shear waves which are used in ultrasonic experiments) in such big objects. In this project unconventional Lamb waves at very low frequencies (30 kHz - 200 kHz) will be used to detect internal defects in civil infrastructures. Initial investigations have shown that for detecting weak bonds and partially damaged internal interfaces, Lamb waves are much more efficient than body waves. However, Lamb wave sensors have not been developed yet to its full potential because of the lack of expertise in this field in sensor industries. In this research the theory necessary to develop efficient Lamb wave or guided wave sensors will be developed first. Then the new sensor will be fabricated with the help of transducer manufacturing industries. These sensors will be tested at the Wright-Patterson Material Laboratory and will be used to detect internal damages in concrete and metal slabs and pipeline type civil infrastructures. Two companion projects are supported to carry out the above described research: University of Arizona which will develop the basic lamb wave theory and conduct initial sensor design and testing, and University of Dayton/Wright Patterson Laboratory which will test the fabricated sensors and evaluate the results. ***