A shell is a three or four-node area object used to model membrane and plate-bending behavior. Shell objects are useful for simulating floor, wall, and bridge deck systems; 3D curved surfaces; and components within structural members, such the web and flanges of a W-Section.
Shells may be homogeneous or layered throughout their thickness. Temperature-dependent, orthotropic, and nonlinear material properties may be assigned to layered shells. Layered shells will exhibit [localization] of nonlinear behavior. Shells may be assigned edge constraints, and may be loaded in any direction, along any side.
Full shell behavior and the Mindlin-Reissner thick-plate formulation are recommended for analysis. Additional options and details are discussed in the
CSI
Analysis Reference Manual (Homogeneous and Layered, page 159).