Edge effects and stress concentrations in multilaminate composite plates

Abstract

1. A refined method was presented for calculating the stress-strain state in the edge zone of a composite multilaminate plate. All conditions of contact at the layer interfaces with respect to both displacements and stresses were observed. An algorithm was presented for computations by the method of boundary functions which makes it possible to determine the rapidly changing terms of the solution at the plate ends and avoids the instability associated with standard methods of solving ordinary differential equations. 2. Based on the above method, we theoretically found and quantitatively evaluated the high stress concentration in the edge zone of a multilaminate plate bounded by two media with different temperatures and pressures. It was established that the •second-degree• (in accordance with classical concepts) components of the tensors of the stresses τxz, τyz, and δz in the soft layer are of the same order as the stresses in the stiff layers. It was shown that the solution obtained by the theory with a •soft filler• [5] corresponds to the zero approximation by the method of boundary functions, and that subsequent interactions produce substantial corrections in determining thermoelastic stresses.