Sensitivity of the flow stress of Nylon 6 and Nylon 66 to strain-rate

The sensitivity of the flow stress of polymers to strain- rate is one of the major concerns in mechanics of materials since polymers and polymer matrix composites are widely used in many engineering applications. In this paper, we present tests on Nylon 6 and Nylon 66 on wide range of strain- rates (0.001- 5000s(-1)). Specifically, we used INSTRON machine for low strain- rates. The high strain- rate measurements were inferred from the Hopkinson bar tests. Only the compressive behaviour was investigated. To eliminate any interference with temperature and humidity effects, test samples were conditioned at 20 degrees C and 50% of hygrometry. Moreover, the effects of the specimen geometry were considered. The current study results are also compared to values found in literature.