Experimental study on crazing initiation and damage in PMMA under creep

A series of creep experiments are carried out for MDYB-3 PMMA under different stresses at the room temperature. The whole process from the crazing initiation and growth to specimen's fracture under creep is researched, finding out that the crazing in PMMA present the alternating distribution of sparse and dense, which is perpendicular to the load. Based on the experimental data and analysis, a relationship between stress and the time of the crazing initiation is given, which quantifies the crazing initiation time shortened non-linear as the stress increases. And a model is built to describe the crazing damage density with stress and time for MDYB-3 PMMA using of non-linear fitting based on hyperbolic function.