Key information SimuDrape model
SimuDrape comes as an add-on for ABAQUS with a fully automatized pre- and postprocessing through plugins for ABAQUS/CAE, as well as advanced modeling approaches through user-subroutines for ABAQUS/Explicit.
For the thermoforming simulation with SimuDrape, the tools as rigid surfaces since the deformations within the tools are expected to be negligible. In contrast, the eight single plies of the orthotropic laminate layup are modeled with deformable shell elements, due to their high slenderness ratio. The single plies are connected via contact constitutive equations, to accurately capture inter-ply sliding between plies.
The processing strategy of this use case includes pneumatic gripper elements at each vertice. These gripper elements are used for the transfer from the oven to the mold, as well as for applying tensile membrane forces during forming, to improve the formability of the laminate. To accurately account for the kinematics of these gripper elements, the ABAQUS built-in translator elements are adopted to model the rotation and elongation of the gripper elements, and the tensile forces are modeled through a force boundary condition in direction of the translator elements. Besides this, gravity loading is accounting for.
Regarding thermal effects, a homogeneous initial laminate temperature of 280 °C and a constant tool temperature of 110 °C is assigned.
Intra-ply material modeling is based on a physically decoupled approach, to accurately model the high fiber stiffness in combination with a low bending stiffness, which is not possible with conventional shell theories. Both membrane and bending behavior are modeled by nonlinear Voigt-Kelvin approach with a temperature-dependent elasticity and a temperature- and rate-dependent viscosity. Temperature-dependency is described by a WLF-approach, whereas rate-dependency is described by a Cross-approach.
Inter-ply material modeling takes into account temperature- and rate-dependent sliding in tangential direction for both the tool-ply and the ply-ply interfaces. For the ply-ply interfaces, additionally, tacking in the normal direction is accounted for.