RELATIONSHIP BETWEEN STRESS INTENSITY FACTOR AND ENERGY RELEASE RATE OF CHINESE-FIR

Abstract

Compact tension specimen and double cantilever beam of Chinese-fir (Cunninghamia lanceolata) were used to measure stress intensity factor and energy release rate of opening cracks (mode-I) in tangential-longitudinal directions in crack body, respectively. The energy release rate was converted to stress intensity factor by Sih, Paris and Irwin relationship. The results showed no significant difference between the converted value of stress intensity factor and value measured by CT specimens. Thus, it is feasible to assume wood as an orthotropic elastic body and to apply the theory of fracture mechanics.