Abstract
In present study, firstly, several basic deformation behaviors of Polycarbonate (PC) were experimentally investigated. Nextly, experiments and analysises based on the over stress theory were conducted on deformation behavior at unloading process. Results obtained from the experiments and the analysises were as follows; (1) Deformation behaviors of the material were very complicated under unloading. Also, it was found from the infrared radiation thermometry method that there was no effect of generation of heat on deformation behavior. (2) Analytical results based on the over stress theory showed agreement with experimental results for deformation behavior under tensile loading. On the other hand, analytical results showed good agreement with experimental results in the case of unloading after tensile loading and full relaxation. But, analytical results did not show agreement with experimental results in the case of unloading after tensile loading.
