Three-dimensional stress analysis in laminated composites with fasteners based on the B-spline approximation

Abstract

Abstract A three dimensional contact problem describing the interaction between a composite plate with a circular hole and elastic fastener has been solved by using the displacement spline approximation and Lagrangian multiplier method. An algorithm capable of adjusting the nonuniform through the thickness contact zone was developed. The converged contact conditions: radial stress and displacement continuity are shown in each ply of a [−45/90/45/0] s laminate loaded in bearing through an elastic fastener. An asymptotic solution of the three body contact problem appearing at the elastic fastener hole edge in a composite laminate is formulated and solved. The power of singularity at a ± 45 ply interface in an AS4/3501-6 laminate with a filled hole was calculated for different stiffnesses of the fastener. At most circumferential locations the power of singularity rapidly increased with increasing fastener stiffness. The behavior of all stress components has been studied in the vicinity of a titanium fastener hole edge and ply interface in a [45/ − 45] S AS4/3501-6 laminate under uniaxial tension. Good agreement between the singular term of the asymptotic solution and spline variational solution for all stress components was observed in the filled hole tension problem.