Comparative Study of Skin–Stringer Connection Approaches for Stiffened Structures with Curvilinear Stiffeners

Abstract

Additive manufacturing enables the deposition of material in the near-net shape at any desired location on the base plate or shell to improve the structural performance by tailoring the buckling and/or vibration mode shapes. In this study, a stiffened plate with arbitrarily shaped stiffeners is modeled using a nonconformal mesh-based finite element model. Six degrees of freedom are considered for each node of the plate and the stiffener finite element models to enable the couplings between the plate’s and stiffeners’ in-plane and out-of-plane motions. Displacement compatibility is enforced at the interface between the plate and the stiffeners where several skin–stringer connection approaches, including inverse isoparametric mapping algorithm (IIMA), radial basis function, and thin-plate spline function, are used. Various complex models available in the literature are employed for evaluating the skin–stringer connection approaches. Research studies show that the IIMA-based nonconformal mesh modeling can generate a sparse displacement approximation matrix, which makes it an efficient approach for nonconformal mesh-based modeling. For the stiffened plate with higher stiffeners, the present results agree well with those obtained from the Abaqus/CAE conventional conformal mesh and mesh tie constraint-based nonconformal mesh modeling results, but yield better results than the Abaqus/CAE wrapping mesh approach.