Interface Model
Mathematical representation of an interface between two layers allows for the simulation of delamination without adding physical volume to the model. In finite element analysis of paperboard, the zero thickness cohesive element defines the bonding strength between the individual plies. This tool uses a traction separation law to govern how the layers stay together or pull apart.
It simplifies the complex physics of internal bonding into a single numerical surface.
Failure Simulation
Virtual forces keep the mesh nodes of adjacent layers connected until a critical stress threshold is reached. Once the load exceeds the bonding capacity, the zero thickness cohesive element begins to soften and eventually breaks. This approach is essential for predicting the creasing and folding behavior of multi ply boards.
It allows designers to see where the paper will delaminate during a sharp bend. Without this element, the simulation would treat the board as a solid block and fail to show the internal shearing.
Material Property
Accuracy in these models depends on the input values for fracture energy and peak traction. These parameters are derived from laboratory tests like the Scott Bond or the Z directional tensile test. Using a zero thickness cohesive element reduces the computational cost compared to modeling every individual fibre.
