Experimental study on the dynamic stress-strain behavior of expanded polystyrene geofoam using cyclic triaxial tests

Dynamic testing of expanded polystyrene (EPS) results in behavior alterations when certain testing criteria are modified. Triaxial testing affirms the behavior of EPS geofoam under axial compression tests related to a seismic compressible inclusion application. An evaluation of initial static deviator stress, load frequency of deviator stress amplitudes, and the effect of static confining stress of EPS geofoam dynamic response are performed. The behavior of viscoelastic and visco-elasto-plastic are compared through the use of cyclic compression tests. Comparative measurements used in supporting behavior change were: Young's modulus, damping ratio, cyclic deviator stress, and plastic axial strains. The resulting data is interpreted through data charts and data trends. Comparative conclusions show significant behavior changes to EPS geofoam when frequency and confining stress influential effects are observed.