The nanofibrillar array of a Gecko inspired Synthetic Adhesive (GSA) adheres to a surfaces when fibers undergo deformations of both the stems and the tip. The GSA’s show interesting changes in effectiveness dependent on use patterns, preloads, and material types, amongst other parameters. The polymers fibers also, display plastic creep even at relatively low strain rates and stresses below plastic yield. Therefore, a suitable numerical solution, which predicts the fiber geometry, must consider not only the initial shape of the fiber, but also the fiber progressive deformation (local and global) and the influence this has on the local mechanical properties (elastic, viscoelastic, strain hardening/softening and plastic flow). The localized mechanical properties are difficult to calculate using traditional methods because of the nonlinearities associated with viscoelastic effects, the large deformations, and the variable boundary conditions. However, the variable boundary conditions make a mesh free modeling method ideal. Smooth Particle Hydrodynamics (SPH) is one of the most prominent mesh free Lagrange method, which takes a set particle and uses particle kinematics, density gradients, and material properties to determine the interaction between particles.

As a first step towards modeling the behavior of a fibrillar adhesive surface, this paper focuses on the modeling of a single polymer fiber. The single micro fiber will be subjected to similar conditions to what it would see as part of an array. This will allow the SPH method of simulation to be critiqued for its further use in simulating polymer microfiber. While the localized mechanical properties of the polymer, which depend on viscoelastic effect and other nonlinear phenomena, are difficult to determine analytically. The modeling technique can be compared to standard analytical methods for global parameters. It was found that the SPH method was able to appropriately model the effect of various scenarios on the mechanical deformation and resonance of a polymer microfiber. Further more the friction force for the fiber on glass was calculated as were the localized fiber velocities and stresses.

This content is only available via PDF.
You do not currently have access to this content.