Incollection,
Experiment and material model for soft tissue materials
Constitutive Models for Rubber VI, CRC Press, Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742, (September 2009)
DOI: 10.1201/NOE0415563277
Abstract
The bulge test is an efficient but simple biaxial setup using only a mittimum of biological material. This experiment is well suited to measure stretches in thin-walled materials such as rubber membranes, chorioamnion, bladder or intestinal lissue, etc. up to the ultimate stretch. The principal stretches are easily calculated from the experirnental data, especially when the tested material shows isotropic behavior. The growth of biological tissue generates residual stresses which can be also measured with the bulge test. Tests with small specimens also permit local measurements of inhomogeneous tissues. In the paper, the small size bulge test is first developed with elastomers. For fitting of the data a modified version of the Kilian network is proposed for hyperelastic modeling of rubberlike materials. This strain·energy function represents both entropic elasticity and in addition energetic elasticity. Fitting the results shows that the proposed model, with only two material constants, can describe the behavior of rubberlike materials up to large elastic strains as accurate as the Ogden model with four or even six material constants. In a second phase the bulge test is used to test planar soft biopolymers or tissues.
