Deflections of a rubber membrane

Spherical indentation of free-standing acellular extracellular matrix membranes

“…A fixed indentation rate and no mechanical preconditioning was 17 employed in this study, as per the governing standard, hence capturing the first time straining of the material until 18 ultimate failure. A previous study demonstrated negligible hysteresis effects during the indentation of rubber 19 membranes [37], however it is possible that preconditioning could improve the analytical model fit to the PDMS 20 membrane behaviour at small deflections.The proposed methodology may be readily implemented with smaller 21 diameter ball burst geometries and alternative strain energy functions to characterize biomaterial membranes under 22 biaxial loading to failure. However, the main limitation with this test method is that material anisotropy cannot be 23 resolved, hence to fully characterize membrane biomaterials, a combined methodology of planar biaxial tension 24 testing coupled with ball burst test data to failure would be beneficial in identifying material coefficients of a 25 suitable constitutive material model.…”

“…Two rigid surfaces 7 representing the experimental clamps constrained the membrane while the rigid ball indenter deformed the 8 hyperelastic membrane. Zero friction was assumed between the smooth indenter and membrane as the ECM 9 multilaminates were hydrated during testing and based on previous experimental reports [37,38]. A `glue' contact 10 condition was defined between the two rigid clamps and membrane.…”

Non-contact experimental methods to characterise the response of a hyper-elastic membrane

“…These include uniaxial, bi-axial, shear and bulge tests (Kim et al 2012;Liu et al 2015;Sasso et al 2008;Selvadurai 2006;Selvadurai and Shi 2012). In the present work, uni-axial tensile testing was performed on a MTS Universal Testing Machine to investigate the response of five rectangular neoprene rubber specimens (10 mm × 170 mm).…”

“…The same rubber sheeting was used for construction of the musical instrument. As done by Selvadurai (2006), additional pieces of rubber were glued to the grip-contact area of the rubber specimens to minimise pull out from the grips. Since the testing was performed within 30 min of applying the adhesive, the possibility of chemical reaction between the rubber specimen and adhesive can be neglected (Selvadurai and Shi 2012).…”

“…Two methods were considered to measure the strain. The first method was similar to that performed by Selvadurai (2006) and Selvadurai and Shi (2012). The displacement of the grips was taken to represent the change in length and the stretch ratio was calculated according to…”