The brittle fracture of polymethyl methacrylate (PMMA) was studied using a high-speed extensometer, which consisted of an optical fiber and a position-sensing detector (PSD). Single-edge-cracked tensile specimens were pin-loaded with a special jig so that they could split and fly in the loading direction after fracture. The flying height and residual deformation of the split specimen were measured to estimate the elastic energy E e and non-elastic energy E n, respectively. By subtracting E e and E n from the external work U ex applied to the specimen, the fracture energy E f for creating a new fracture surface was evaluated. The results showed that E e, E n, and E f increased with U ex, and the ratio E f/U ex was about 45% over a wide range of U ex. Energy release rate was also estimated using U ex or E f, and the results suggested that it was overestimated if E e and E n were included.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Mechanics of Materials
- Mechanical Engineering