Search

Abstract: Wave propagation and its frequency bandgaps in a parametrically modulated composite laminate are reported in this paper. The modulated properties under considerations are due to periodic microstructure, for example honeycomb core sandwich composite, which can be parameterized and homogenized in a suitable scale. Wave equations are derived by assuming a third-order shear deformation theory. Homogenization of the wave equations is carried out in the scale of wavelength. In-plane wave and flexural–shear wave dispersions are obtained for a range of values of a stiffness modulation coefficient . A clear pattern of stop-bands is observed for . To validate the band-gap phenomena, we take recourse to time domain response obtained from finite element simulation. As predicted by the proposed analytical technique, a distinct correlation between the chosen frequency band and the simulated wave arrival time and amplitude reduction is found. This promises practical applications of the proposed analytical technique to designing parametrically modulated composite laminate for wave suppression. [Copyright &y& Elsevier]

Describes the ES-9400 shearography system, which performs nondestructive testing of honeycomb and composite structures in the field or hangar or in production. Features, including a lightweight inspection head, remote laser, and a monitor that presents results in real time.

Researcher Jean-Pierre Tortignon developed an economical technique in which plates or tubes with the honeycomb sandwiched between two outer coverings are made using most types of extrudable building material, especially ceramics and fibrous cements. The process permits fluids, wires, and other substances to run through the structure's interior. Potential applications for Tortignon's process in the field of industrial ceramics include pollution systems, catalytic exhaust system, heat exchangers, structural tubing and drainage and filtration systems. He holds patents on the production technique in 37 countries.