Experimental Study On Interface Delamilation Detection Of Glued Bamboo Beams Using Piezoelectric Ceramics

The production of traditional building materials including steel and concrete leads to environmental problem.In recent year,glued bamboo structures by gluing natural bamboo fibers together have been employed in practice.Hence,it is great of significance to monitor and evaluate the interface bonding condition of glued modern bamboo structural members.Because the defect of the vertical interfaces of the glued bamboo beam has obvious effect on the global stiffness and strength and is invisible,the development of efficient interface condition monmitoring approach is important.Aiming at interface bonding condition monitoring of Glued bamboo beams,two interface debonding condition approaches using stress wave propagation and impedance measurement are proposed.Specific work include as follows:1.Piezoelectric material and their application in structural health monitoring usingstress wave and impedance measurement are introduced in detail and the basic mechanical properties of Glued bamboo material are further described.2.A scale model of Glued bamboo beam with surface mounted PZT patches is designed and loading tests on the specimen and interface debonding detection are carried out.3.By analyzing the stress wave measurement,propagation time and the wavelet packet energy and other characteristic parameters under harmonic and sweep frequency signals,damage indices are defined to detect the interface debonding defects,4.Impedance based interface debonding detection approach is applied to detect the interface condition of the glued bamboo specimen under difference loadings.The root mean square deviation(RMSD)of the impedance measurement is employed to detect the interface debonding condition of Glued bamboo beam.The strain of the specimen is also recorded.Because the defect in the vertical interface does not have obvious effect on the stiffness and load-carrying capacity of the glued bamboo specimen,the interface debonding detection approach with PZT shows its obvious advantage.