A C(0) 3-NODE SHELL ELEMENT FOR NONLINEAR STRUCTURAL-ANALYSIS

A C0 three-node shell finite element well suited to non-linear calculations is proposed. The element is based on Mindlin kinematics and the degenerated solid approach. Linear Lagrange functions are used for geometry and displacement interpolations. The formulation is made in the natural material frame. A strain interpolation avoids shear locking and an intermediate material frame related to the element sides is introduced in order to fix nodal transverse shear strain components. The modifications of strain interpolations concern both the non-linear and linear parts of strain and are taken into account in all calculations, among others in the expression of the initial stress stiffness matrix. A single set of integration points on the normal at the centre of gravity is sufficient, which is very interesting for numerical efficiency especially in the case of non-linear analyses.