The experimental approach is the main focus of existing research on the mechanical properties of nanofiber materials. This include the improvement on such properties of composite materials with nanofibers. A significant number of recent investigations were seeking mechanical properties of nanofibers, mainly on obtaining mechanical properties of single nanofibers. Sophisticated experiments were designed using MEMS and results were recorded and analyzed with good accuracy. Todate there are no theoretical models exist to validate the results.
In contrast, this work concentrates on obtaining mechanical properties of nonwoven nanofiber materials such as, Young's modulus, and damping, both theoretically and experimentally. Specifically a fabric made from polyethylene based nanofibers, was chosen as a candidate for investigation. This approach presented here is simple, cost effective, and more practical. Since most applications that use nanofiber materials are nonwoven nanofibers in the form of a fabric or a mat rather than single nanofiber, this experiment was conducted to test actual material made from nanofibers.
The fabric made from polyethylene nanofibers with super absorbent particles is in a form of a thin membrane, and a mathematical model for forced vibrations was designed and tested to obtain material parameters. In the experiment forced vibrations were induced and three dimensional CCD cameras were used to record the displacements.
A nonlinear optimization method was developed to determine the material parameters. To verify the validity of the method that was used to recover material parameters, noise was added to the data from exact solution to simulate a set of experimental data with assumed known properties. Errors were then calculated from original generated data. The minimized error yielded to the material parameters. This procedure was followed to obtain some mechanical properties from the actual experimental data.
The observed parameters are of the same magnitude that was reported for a single nanofiber. In addition, this procedure can be extended to nonlinear shell models with additional material parameters present.