Multi-Layer Thick Shells

We present a novel mesh-based method for simulating the intricate dynamics of (potentially multi-layered) continuum thick shells. In order to accurately represent the constitutive behavior of structural responses in the thickness direction, we develop a dual-quadrature prism finite element formulation that is free from shear locking and naturally incorporates three-dimensional elastoplastic and viscoelastic constitutive models. Additionally, we introduce a simple and effective technique for coupling a high-resolution membrane layer on top of the thick shell to enable complementary high-frequency deformation modes that generate realistic wrinkles. With our novelly designed sparse basis vectors for the high-frequency deformations, the constrained Lagrangian mechanics problem is expressed as an unconstrained optimization and then efficiently solved by a custom alternating minimization technique. Our method opens up a new possibility for fast, high-quality, and thickness-aware simulations of leather garments, pillows, mats, metal boards, and potentially a variety of other thick structures.