Mechanical Property of Celluloid under Proportional Loading

Abstract

In order to investigate the effects of loading history and variation of temperature on the deformation behavior of softened celluloid by heating, the proportional loading tests were made at a constant temperature on specimens made of a celluloid plate and a thin walled cylindrical celluloid tube for various periods of heating time. The effect of heating time on the mechanical property of the material was examined, and the Poisson's ratio and the stress-strain relations under tensile and torsional loadings were discussed. The conclusions obtained are summarized as follows:(1) The mechanical property of celluloid is not affected by heating time.(2) The residual stress appearing in the thin walled cylindrical tube specimen is small and an isotropy in a plane is maintained.(3) The Poisson's ratio is 0.47 and the incompressible condition is satisfied still for the inelastic deformation within the range of 6 percent error.(4) The deformation resistance of torsional loading is larger than that of tensile loading. This may be attributed to the effect of a first invariant of stress tensor.