Viscous criterion and its relation with the projectile-thorax energy interactions

Despite many injury criteria to measure thoracic trauma in known engineering parameters, viscous criterion, that is a product of maximum instantaneous velocity of thorax deformation and maximum instantaneous chest compression, has been widely used. Using Lobdell mathematical model of the thorax, Wang [1] has carried out analytical studies and proved that peak viscous response is related to the peak energy storing rate of the thorax and also proved that it does not related to viscosity of the thorax. Authors have carried out a scholastic study by impacting a FE model thorax MTHOTA (Mechanical THOrax for Trauma Assessment), which is fully validated for blunt ballistic impacts, with a foam nose projectile with speeds of 30 – 90 m/s with an increment of 5 m/s. VCmax values and projectile – thorax energy interactions were evaluated and presented in this paper. From the outcome of the simulations, relation between maximum stored energy