Dynamic Stress-strain Compressive Response of Soft Tissue using Polymeric split- Hopkinson Pressure Bar

Abstract

The characterization of soft tissues subjected to higher compressive strain rates is of increasing importance as the material properties of soft tissues were commonly used in impact applications such as automotive safety and crashworthiness for biofidible numerical modeling of the human body. Due to less availability of stain rate dependent data in the open literature and various challenges in the characterisation of soft tissues under impacts, need were felt for characterisation of soft tissues at higher strain rates. The purpose of this study is to investigate the dynamic mechanical behavior of soft tissues at varying compressive strain-rates. The viscoelastic split Hopkinson pressure bar (SHPB) is designed and developed to predict the high rate compressive behavior of soft tissues. The primary benefit in using viscoelastic bars is the reduced bar impedance allowing for high-quality measurements of the transmitted and reflected stress wave signals. The dynamic behavior of goat muscles has been measured at higher strain rates ~500-1200 s-1 using a polymeric SHPB apparatus. The dynamic stress-strain response of muscle tissue exhibits non-linear behavior under compressive loadings and is strain-rate dependent.