Three-dimensional strain evaluation of short-fiber-reinforced natural rubber using micro X-ray computed tomography

Abstract

The vibration damping appears as a macroscopic material property due to the energy dissipation caused by the plastic deformation of the microstructure in the material, but the detailed mechanism is still unknown. This study prepared a damping material based on natural rubber (NR) and investigated its deformation behavior with/without fiber-shaped particles using synchrotron X-ray computed tomography (CT). High-resolution submicron X-ray CT was performed to evaluate the local strain in the microstructure from feature points scattered inside the NR. When the strain distribution changed under stepwise tensile loading, the NR-alone material deformed uniformly at the microscale, whereas the fiber composite rubber deformed nonuniformly. Furthermore, the number and volume of voids increased significantly with the compounding of fiber particles, and their values continued to increase depending on the strain amplitude and the loss factor. Controlling of non-uniform local strain and void formation will enable the design of damping characteristics.