A SIMPLE CONSTANT STRAIN-ENERGY RELEASE RATE LOADING METHOD FOR DOUBLE CANTILEVER BEAM SPECIMENS

A simple loading arrangement is proposed to permit nearly constant str ain energy release rate testing of double cantilever beam specimens. T he inexpensive arrangement may be well suited to long term and environ mental exposure testing of these specimens. An added advantage of the technique is that it also provides an attractive method to measure deb ond length. The geometrically nonlinear loading device provides consta nt strain energy release rate loading under idealized conditions. Anal ysis of the technique for realistic conditions reveals the appropriate test window for the device, and allows design guidelines to be develo ped. Experimental evaluation confirms the analytical predictions.