Energy Release Rate in a Constrained Polymeric Disk under Internal Pressure and Thermal Loads

In this study, the energy release rates in a centrally perforated star-shaped disk, which was made of a polymeric material, under internal pressure and thermal loads, were determined. The deformations of the disk were constrained by a circular steel ring enclosing the disk. Two constitutive models, namely, Hookean model and Ogden model, were used to model the constitutive behavior of the material. Three different loadings, internal pressure, isothermal load, and combined internal pressure and isothermal load, were considered. Numerical results showed that values of the energy release rate were very sensitive to Poisson’s ratio for the pressure load. The decrease in the compressibility gave a higher value of energy release rate for the pressure load and a lower value of that for the isothermal load. The deformed crack profiles were also determined to address the compressibility effect on the energy release rate.