Quasistatic and Dynamic Compressive Behavior of Gelatin Available to Purchase

Gelatin has been extensively used as a tissue stimulant. Determination of properties and tits constitutive behavior is crucial to successful use of gelatin in these applications. In this study, ballistic gelatin was used because the recipe to prepare the gelatin and its quasi-static strength (250 bloom) of this particular type of gelatin is well known [1]. Although the study for high rate deformation is important to understand the damage from blast impact, majority of the currently available material property data is in quasi-static range [2,3]. Generally, polymeric materials (including human tissue) exhibit highly rate sensitive response [4]. Therefore, the understanding of the constitutive behavior for these materials at high rate loading is essential. This study will provide the rate sensitivity of gelatin by comparing the response under quasi-static and dynamic loading. In order to investigate the dynamic behavior of gelatin, the split Hopkinson pressure bar (SHPB) was used in this study. Because use of a solid metallic bar to test such soft materials does not provide an adequate transmitted signal, a polymer split Hopkinson pressure bar (PSHPB) was used to reduce the impedance mismatch between bar and soft gelatin specimen. The nature of dispersion and attenuation was corrected using an iterative scheme developed earlier [5].