Comparison of Thermal Maps with Damage Revealed by Silicone Impregnation

Two different techniques were used to detect the local fracture process zone of paper. The silicone impregnation technique was used to reveal the area where broken bonds scatter light. Thermographic technique was used to measure the local temperature variation at crack tip. In the in-plane tear test, the area where temperature rises was larger than the area of damage revealed by the silicone technique. This could derive from heat generation during elastic destraining. In the short span tensile test, temperature profile was the same as in the in-plane tear test for every sample. On the basis of our results, the fracture process zone does not seem vary much between different in-plane test geometries.