Elastomer testing: the risk of using only uniaxial data for fitting the Mooney-Rivlin hyperelastic-material model

Abstract

The Mooney-Rivlin constitutive model is often used for the characterization of hyperelastic rubber-like materials. To obtain the material constants for a model, only a uniaxial-tension-data set is usually used. Though it is regularly used for its easiness of processing data in a simple and practical way, the method is considered to be insufficiently accurate. To analyse the shortcoming of the method, a detailed examination was done with the Mooney-Rivlin two-parameter model. This paper discusses the variations related to three basic load curves, i.e., uniaxial, equibiaxial and pure-shear curves. For a visual observation of the fitted-data dispersion, two data-fitting cases were considered. The first one was the data fitting only through uniaxial data while the second one was a combination of uniaxial and pure-shear experimental-data curve fitting. A detailed one-to-one comparison of the curves was done to achieve an accurate estimation of the variations. Keywords: uniaxial tension, equibiaxial loading, pure shear/planar shear loading, curve fitting, Mooney-Rivlin constitutive modelMooney-Rivlinov temeljni model se pogosto uporablja za karakterizacijo gumi podobnih hiperelasti~nih materialov. Za materialne konstante se obi~ajno uporablja set podatkov, dobljenih z enoosnim nateznim preizkusom.^eprav se ta na~in uporablja zaradi enostavnosti in prakti~nosti metode pa ga lahko smatramo kot manj natan~nega. Zato, da bi avtorji tega prispevka ugotovili neskladje, so izvedli natan~no analizo z Mooney-Rivlinovim dvoparametri~nim modelom. V~lanku avtorji obravnavajo variacije, ki se nana{ajo na tri osnovne krivulje obremenjevanja: enoosno, ekvivalentno dvoosno in~isti strig. Vizualno opazovanje raztrosa prilagojenih podatkov so izvedli na osnovi dveh na~inov prilagajanja podatkov. Prvo prilagajanje podatkov so izvedli na osnovi rezultatov enoosnega nateznega preizkusa. V drugem primeru so uporabili kombinacijo obeh: eksperimentalne rezultate enoosnega nateznega preizkusa in~istega striga. Izvedli so natan~no primerjavo krivulj in ocenili odstopanja. Klju~ne besede: enoosni nateg, ekvivalentna biaksialna obremenitev,~isti strig, ravninska stri`na obremenitev, prilagajanje krivulje, Mooney-Rivlinov konstitutivni (temeljni) model

Low Impact Velocity Modeling of 3D Printed Spatially Graded Elastomeric Lattices

“…For instance, the Mooney–Rivlin material model is appropriate to simulate natural rubber of up to a 100% tensile strain [ 56 ], while the Ogden 3rd-order material model better fits carbon black-reinforced rubber with tensile data of up to ε = 6.0, while the Yeoh material model works properly for natural rubber reinforced by carbon-black [ 57 , 58 ]. Particularly for TPU, Ogden, Yeoh, and Mooney–Rivlin material models can be fitted properly if diverse experimental data are within reach [ 59 , 60 , 61 ], but if only uniaxial tensile data are available, the Ogden model provides better results than the other two [ 59 , 62 , 63 ]. Therefore, in this work, the quasi-static average stress–strain curve was fitted to an Ogden 3rd-order material model by using HYPERFIT ® 2.181, which was used as the model input.…”

Study on the Mechanism of Rootstock Damage during Clamping in Watermelon Grafting

“…Silicone rubber is an elastic material, and it is assumed to be incompressible, which means that its volume is kept constant before and after deformation. The Mooney-Rivlin model was commonly used to describe the properties of rubber-like materials [25,26]. The model parameters obtained through the test are shown in Table 1.…”

Effect of Interlayer Stress on U Bends and Water Droplet Bends

“…In engineering, the strain energy density function is generally used for rubber to characterize the superelasticity of the material. e polynomial strain energy function in the analysis has been more widely used in finite element analysis [16]. For rubber in terms of similar incompressible physical nonlinear materials, the Mooney-Rivlin strain energy function is the most common choice.…”