Mixed MITC and interface shell element formulation for multi-part viscoelastic shell structures

This study presents a novel approach for constitutive modeling of multi-part viscoelastic shell structures using a combination formulation of mixed MITC (MITC3 and MITC4) and interface shell elements with reduced computational cost. It focuses on accurate viscoelastic analysis, considering the time-dependent behavior of the multi-part shell structures. The use of the Laplace transform simplifies the integral-form constitutive equation, enabling efficient and accurate viscoelastic analysis. Moreover, by combining the advantages of MITC shell elements and interface shell elements, this approach comprehensively represents multi-part shell structures with non-matching interfaces. Hence, it allows the meshing of each component part independently when assembled. Furthermore, these methods also provide better resistance to shear and membrane locking, which can be problematic when modeling thin shell structures. In numerical examples, to validate the accuracy of the current study, we meticulously analyze multi-part shell models such as an elastic U-shaped beam and the viscoelastic propeller subjected to creep bending loads. This research contributes to improving the design and performance of shell structures in various engineering fields.