A comparative study of whole-field stress between digital photoelasticity and infrared radiation testing applied for PMMA

In this study, a series of diametral compression and three-point bending on PMMA were performed to investigate the distribution and evolution of whole-field stress through combining infrared thermography and digital photoelasticity technology. To compare the whole-field stress distribution characteristic of PMMA under the same mechanical experiments, it can be seen the principal stress sum variation law determined by infrared radiation was the same as the principal stress difference obtained by digital photoelasticity. The difference between infrared radiation and digital photoelasticity in describing evolution characteristics of whole-field stress has also been analyzed. Based on the infrared thermography and digital photoelasticity two basic tests, enabling a further reference for analyzing whole-field stress measurement of solid materials through compared principal stress sum and principal stress difference. This study provides a new thought to determine the yield and deformation of materials in real-time, thereby serving as an experimental basis for analyzing the whole-field stress of materials in complicated loading conditions.