Strains in an Inflated Rubber Sheet

Abstract

A technique to measure the strain distribution of an inflated membrane is described, and applied to natural rubber inflated to pole biaxial strains of 12%, 26%, and 33%. The radial strain was found to be nearly constant over the entire surface, while the circumferential strain falls to zero at the edge. Thus, biaxial deformation is limited to a narrow region in the vicinity of the pole. These results are quite different from (the very limited) data published previously. The stressstrain behavior was also measured in uniaxial tension, and the strain distribution of the inflated membrane calculated using finite elements. The experiment results and the modeling were in good agreement.

A novel nano‐bubble inflation method for determining the viscoelastic properties of ultrathin polymer films

“…Such timedependent behavior is a result of the viscoelastic nature of polymers and the technique described here is unique in being able to directly measure the time-domain response of ultrathin polymer films. The method is based on the classical "bubble inflation" method of measuring the biaxial elastic or viscoelastic creep response of a film (Green, 1970;Joye et al ., 1972;Treloar, 1975;Wineman, 1976;Mott et al ., 2003), reduced for nanometer thickness films of interest. The technique uses an AFM to image the nano-bubbles as a function of time, temperature and film thickness.…”

Estimation of the Elastic Properties of Polymer Plates Using a Structured Light Technique

“…The bulge test has been successfully applied [6,9,12,[15][16][17][18][19][20][21][22][23][24][26][27][28][29] and differences have been observed in comparison with uniaxial tests. This test is suitable for investigating polymer blends for large biaxial plastic deformation prior to failure [16].…”

“…As an alternative, the bulge test is used for determining the mechanical properties under biaxial tension conditions with small bending component [5]. Among the different test methods for Young's modulus determination, the bulge test has become popular for sheet metal [6][7][8][9], thin films [10][11][12][13], polymers [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], and biological materials [29]. In comparison to uniaxial tests, higher strain values can be achieved by bulge tests [7,16] and the maximum strain obtained in uniaxial tensile test before necking is relatively small [6].…”

The Significance of Equi-Biaxial Bubble Inflation in Determining Elastomeric Fatigue Properties

“…Bubble inflation has been used extensively in the past to study the hyperelastic behaviour of rubber [62,63,64,65,66,67,68,69] and the research described here had its beginning in a project carried out in Robert Bosch GmbH. Johannknecht et al [70,71,72] pneumatically and hydraulically inflated nitrile rubber test samples to failure to determine material constants for hyperelastic FE analyses and also offered plausibility criteria for these constants [73].…”