Talk:Elastic energy

message: It seems self-evident that this article and the article on Elastic potential energy are on exactly the same subject and should be merged. I suggest this page be left as a redirect. Comments? --71.198.38.153 09:20, 21 August 2007 (UTC)
replies: text: Agreed, go for it! ;) Random89 (talk) 21:14, 29 November 2007 (UTC)
replies: text: Most definitely merge it.  As both pages are quite short, each would benefit the other, and I gather that “elastic potential energy” is a more scientifically proper term, so using this article as a redirect seems wisest as well.  The redundancy here represents many ‘clone’ articles that are somewhat embarrassing for Wikipedia, and the sooner it is rectified the better.  Kudos for putting this on the radar.  Wii Owner 3.14 (talk) 05:46, 1 April 2008 (UTC)
thread_title:  Merge article with [[Elastic potential energy]] 

message: I corrected the definitions and notational harmonization with respect to the elasticity of material in a continuum and noted same in comments above.  However, as I look at the other parts of the article I see some fundamental errors.  I will correct one more now and perhaps return to this later, but before doing more I'd like anyone who has a larger view of the present connection between this and other articles to please comment.  Depending on the comments, it might make sense to collaborate to further improve the article.  Incidentally, despite a lack of transition, the thermodynamic definition at the top might arguably be related to the elasticity definition -- if for no reason other than the fact that potential energy is widely and consistently defined in terms of it.  However, it is also arguable that the thermo def is not about elasticity per se which is normally confined to non-fluid systems.  The physics at a low enough level corresponds, but it might be wise to dispense with the thermo part and focus on making the rest of the article clearer and more robust. Comments invited.  In the meantime I will fix the opening derivation -- to wit: 
Beware that while E is a general notation for energy, in the context of elasticity E is very commonly used to denote Young's modulus -- which also has other commonly used symbols.  Anyway, lambda and mu are the common symbols for the lame' constants, but these mostly occur in continuum elasticity. Young's modulus can be defined in terms of lame constants.  In any case, the first and second equation are not related to each other by the text and there is an inexplicable change in notation for the elastic energy.  It is certainly true that k is the elementary text book convention for Hooke's constant -- but that constant is defined for a spring of known initial length, whereas the moduli are independent of the scale of the system.   Let me clean this up and and then someone can comment on the improvement. scanyon 00:38, 6 June 2010 (UTC)
thread_title:  Correcting basic physics of the article 

message: I think there is a mistake in the formular for elastic energy / Helmholtz potential of an isotrophic linear elastic continuum in this article. But I'm not an expert and don't have appropriate literature at hand at the moment. That's why I don't dare to change the actual article.
I think instead of:
: f(\epsilon_{ij}) = \lambda \left ( \sum_{i=1}^{3} \epsilon_{ii}\right)^2+2\mu \sum_{i=1}^{3} \sum_{j=1}^{3} \epsilon_{ij}^2
it should be only half of that:
: f(\epsilon_{ij}) = \tfrac{1}{2} \lambda \left ( \sum_{i=1}^{3} \epsilon_{ii}\right)^2 + \mu \sum_{i=1}^{3} \sum_{j=1}^{3} \epsilon_{ij}^2
I checked by substituting into
: \sigma_{ij} = \left ( \frac{\partial f}{\partial \epsilon_{ij}} \right)_S. 
and compared to the formular given in Hooke's_Law:
:
   \sigma_{ij} = \lambda~\varepsilon_{kk}~\delta_{ij} + 2\mu~\varepsilon_{ij}   —Preceding unsigned comment added by 202.72.132.182 (talk) 05:45, 1 April 2011 (UTC)
thread_title:  Possible mistake in formular 

message: ;? Tugzy76 (talk) 07:40, 12 August 2015 (UTC)
thread_title:  j 

message: The work that can be done by a stretched rubber is due the entropic force, not potential energy. See the wikipedia entry for https://en.wikipedia.org/wiki/Rubber_elasticity : "The result is that an elastomer behaves somewhat like an ideal monatomic gas, inasmuch as (to good approximation) elastic polymers do not store any potential energy in stretched chemical bonds or elastic work done in stretching molecules, when work is done upon them." So I am removing the link to rubber motor and adding a single sentence noting the difference.
It would be great if someone could provide a more comprehensive discussion of entropic elasticity in this entry.
Nick (talk) 18:48, 19 December 2015 (UTC)
thread_title:  Rubber motor is NOT an example of elastic POTENTIAL energy 

message: Add the modulus of resilience as it is the elastic energy stored in a material when stretched. 83.247.101.111 (talk) 09:12, 11 February 2023 (UTC)
thread_title:  Modulus of Resilience