Design variation of thin walled composite beam cross section properties
Purpose The purpose of this paper is to present a design sensitivity analysis continuum formulation for the cross section properties of thin walled laminated composite beams. These properties are expressed as integrals based on the cross section geometry, on the warping functions for torsion, on shear bending and shear warping, and on the individual stiffness of the laminates constituting the cross section. Design/methodology/approach In order to determine its properties, the cross section geometry is modeled by quadratic isoparametric finite elements. For design sensitivity calculations, the cross section is modeled throughout design elements to which the element sensitivity equations correspond. Geometrically, the design elements may coincide with the laminates that constitute the cross section. Findings The developed formulation is based on the concept of adjoint system, which suffers a specific adjoint warping for each of the properties depending on warping. The lamina orientation and the laminate thickness are selected as design variables. Originality/value The developed formulation can be applied in a unified way to open, closed or hybrid cross sections.