Talk:Hyperelastic material

Merge rubber elasticity?
The Rubber elasticity article is fairly brief and states in the lead that it is synonymous with hyperelasticity. If that is correct (anyone?), I propose merging it in here. Thoughts? Dhollm (talk) 21:44, 23 August 2010 (UTC)
 * Hyperelasticity applies to all materials and is a more general concept than rubber elasticity. Rubber elasticity should deal with models of rubber and the current article does that to some extent.  The Rubber elasticity article can be expanded significantly to include other, more realistic, models of rubber behavior.  I suggest that we keep them separate.  Bbanerje (talk) 22:31, 23 August 2010 (UTC)
 * So in that case, I take it the lead of the rubber article is incorrect? Dhollm (talk) 22:35, 23 August 2010 (UTC)
 * There are texts on elastomeric materials in which hyperelasticity is called rubber elasticity. So there is some precedence. And the several hyperelastic material models and much of the modern development of the theory did grow out of work on rubber.  However, the theory of hyperelasticity was first presented in a paper in 1837 by Green.  The introduction to rubber elasticity could do with some caveats. Bbanerje (talk) 02:35, 25 August 2010 (UTC)
 * Thanks again for your input, that explanation makes sense. It seems then that merging would not be the correct thing to do, as long as the articles are clear on what they cover. I have removed the merge tags and made a slight change to the lead in the rubber article; please feel free to adjust/expand upon that if you think it is necessary. (The historical aspect could be touched upon). Best, David Hollman (Talk) 07:48, 25 August 2010 (UTC)



Expressions for the Cauchy stress - Incompressible isotropic hyperelastic materials
The section Hyperelastic material, the part "If in addition $$I_1 = I_2$$, then..." is in my opinion wrong (did some examples, can present a counterexample, but would be interested if I am mistaken), my guess is that the assumption should read $$\hat W=\hat W(I_1)$$ or $$\partial\hat W / \partial I_2 = 0$$.

But before fixing the possible typo: The information in the rest of the section is rather trivial, including the following case (equibiaxial extension, $$\lambda_1=\lambda_2$$). Why not ommit both special cases? One could easily obtain these by just substituting into the general formula. Also, other special cases could be thought of, which are not mentioned here - what makes the two so important? The $$I_1$$-dependence is perhaps somewhat important (considering the material models in widespread use, such as neo-Hookean or Yeoh), but the individual deformation modes are already treated on the pages of some of the particular hyperelastic models, e.g. Neo-Hookean solid or Mooney-Rivlin solid. Heczis (talk) 09:48, 11 September 2023 (UTC)