Effects of Extension Rate on Mechanical Behaviors of PMMA

An experimental study of rate-dependent mechanical behavior of Poly methyl methacrylate (PMMA) was carried out under uniaxial tension, three-point bending and fracture toughness tests. To assess the extension-rate sensitivity, five most-used rates i.e. 0.1, 0.5, 1, 5 and 25 mm/min were employed. All three tensile, bending and fracture experiments were in accordance with relevant standards and their loads were applied and monitored versus displacements until the specimens failed. Additionally, digital image correlation (DIC) method was utilized to better understand the impacts of rate-dependent test on the elastic modulus and strength of PMMA under tensile loading conditions. The findings of this study indicated the extension rate of tensile and bending experiments had vivid effects on the mechanical properties of PMMA. The more values of extension rates, the higher the value of tensile and flexural moduli and strength attained. However, fracture toughness values were affected less by varying the extension rate compared to other tests and followed no specific trends. Such changes in mechanical properties of PMMA in response to different extension rates may require an explanation involving PMMA time-dependent behavior

Keywords:

Poly (methyl methacrylate) , Digital image correlation method , Extension-rate sensitivity , Mechanical behavior