Review of in situ fabrication methods of piezoelectric wafer active sensor for sensing and actuation applications

摘要: Structural health monitoring (SHM) is important for reducing maintenance costs while increasing safety and reliability. Piezoelectric wafer active sensors (PWAS) used in SHM applications are able to detect structural damage using Lamb waves. PWAS small, lightweight, unobtrusive, inexpensive. achieve direct transduction between electric elastic wave energies. essential elements the Lamb-wave with pitch-catch, pulse-echo, electromechanical impedance methods. Traditionally, integrity tests required attachment of material surface. This often a burdensome time-consuming task, especially considering size magnitude surfaces measured (such as aircraft, bridges, supports, etc.). In addition, there critical where rigid piezoceramic wafers cannot conform curved surfaces. Existing ceramic PWAS, fairly accurate when attached correctly substance, may not provide long term durability SHM. The bonded interface structure weak link. Better be obtained from built-in sensor that incorporated into material. An in-situ fabricated smart offer better durability. paper gives review state art on fabrication different approaches, such piezoelectric composite approach; polyvinylidene fluoride (PVDF) approach. It will present principal methods results existing date. Flexible PVDF have been studied. They were mounted cantilever beam subjected free vibration testing. experimental compared conventional PWAS. theoretical this study gave basic demonstration piezoelectricity