Analysis of cracked beams using photoelasticity

An experimental photoelastic stress analysis method has been developed to analyse cracked beams. Test samples made from, ARALDIT CT-200 material are loaded in simple bending and the depth span ratio of these samples H/L varies from 0.15 to 0.5. At constant depth span ratio the crack depth ratio a/H varies from 0.0 to 0.5. Two cases of loading are considered. The first is a concentrated load is applied in the middle of the span of value 20 Kg. The second is two concentrated loads applied at two points and each load of value 10 Kg. Test data were obtained and analysed using computer program utilizing the shear difference method of analysis. The valu~ of stress-intensity factor (KI) had been obtained for’ all models experimently and compared ,with theoritical solution obtained from fracture mechanics techniques. The normal stresses S , ~ x y xy obtained also at all s~ctions of models. The main advantage of the present method lies on the fact that it can be extended to analyse complicated structural geometries where theoretical fracture mechanics solutions are not available.