Modeling of constitutive behavior for epon 828/T-403 at high strain rates

Experimental results on the uniaxial compressive stress-strain behavior of Epon 828/T-403 over a strain rate range from 1.1 x 10(-4) to 5.2 x 10(3) s( -1) were simulated using a viscoelastic viscoplastic constitutive model dev eloped by Hasan and Boyce (1995). An optimal combination of material parame ters for the constitutive model was determined by curve-fitting the experim ental results. A comparison between the modeling and experimental results s hows that this model, with proper parameters, is capable of capturing the s train-rate effects, as well as the typical polymeric compressive stress-str ain behavior, of Epon 828/T-403, which includes the stages of linearly elas tic, nonlinearly elastic, yield-like (peak) behavior, strain softening, and nearly perfect flow. For all the stress-strain behavior modeled over seven decades of strain rate span, the maximum error between modeling and experi mental results is less than 25%. The temperature increase induced by the di ssipated plastic work is also computed and found to be between 3 and 8 degr eesC at these strain rates.