  The adhesive behaviour of biological attachment structures such as spider web
anchorages is usually studied using single or multiple peeling models involving
"tapes", i.e. one-dimensional contacts elements. This is an oversimplification
for many practical problems, since the actual delamination process requires the
modelling of complex two-dimensional adhesive elements. To achieve this, we
develop a numerical approach to simulate the detachment of an elastic membrane
of finite size from a substrate, using a 3D cohesive law. The model is
validated using existing analytical results for simple geometries, and then
applied in a series of parametric studies. Results show how the pull-off force
can be tuned or optimized by varying different geometrical or mechanical
parameters in various loading scenarios, and the length of the detachment
boundary, known as the peeling line, emerges as the key factor to maximize
adhesion. The approach presented here can allow a better understanding of the
mechanical behaviour of biological adhesives with complex geometries or with
material anisotropies, highlighting the interaction between the stress
distributions at the interface and in the membrane itself.
