Statically undetermined multilayered beam of non-linear viscoelastic behaviour: a delamination study

Abstract

Delamination of a twice statically undetermined multilayered beam structure which has non-linear viscoelastic behaviour is studied analytically. The beam is made of layers whose time-dependent behaviour is treated by a non-linear viscoelastic mechanical model having equal number of springs and dashpots. The strain energy release rate is derived by analyzing the balance of the energy. The curvatures and the coordinates of neutral axes of the beam portions needed for obtaining of the strain energy release rate are found by resolving the static indeterminacy. The delamination is studied also by the method of J-integral to verify the strain energy release rate. In order to evaluate the effect of the static indeterminacy, an analysis of the strain energy release rate is carried-out also assuming that the beam under consideration is statically determinate structure.