High Strain Rate Pure Shear and Axial Compressive Response of Porcine Lung Tissue

Abstract

In this study, both the dynamic shear (torsion) and axial compressive responses of porcine lung tissue were examined using modified Kolsky bar techniques. High-rate compression data were collected using a Kolsky bar with a hollow transmission bar on annular specimens at strain rates between 1000–3000 s−1. The radial deformation of the annular specimen was recorded on a modified single loading Kolsky bar using high-speed imaging capabilities. The collected images and analysis of boundary movement indicated inhomogeneous specimen deformation induced by radial inertia, which significantly altered the desired uniaxial stress state in such high-rate compression test techniques. A novel torsion experimental technique was developed to obtain the dynamic pure shear behavior of lung tissue at shear strain rates above 500 s−1 without inertia effects. The pure shear response was found to be two orders of magnitude weaker than the uniaxial compressive response when compared by equivalent stress–strain relations.