A Mooney-Rivlin solid is a generalization of the w:Neo-Hookean solid model, where the strain energy W is a linear combination of two invariants of the w:Finger tensor :
where and are the first and the second invariant of w:deviatoric component of the w:Finger tensor:
where: and are constants.
If (where G is the w:shear modulus) and , we obtain a w:Neo-Hookean solid, a special case of a Mooney-Rivlin solid.
The stress tensor depends upon Finger tensor by the following equation:
The model was proposed by w:Melvin Mooney and w:Ronald Rivlin in two independent papers in 1952.
Comparison of experimental results (dots) and predictions for w:Hooke's law
(1, blue line), w:Neo-Hookean solid
(2, red line) and Mooney-Rivlin solid models(3, green line)
For the case of uniaxial elongation, true stress can be calculated as:
and w:engineering stress can be calculated as:
The Mooney-Rivlin solid model usually fits experimental data better than w:Neo-Hookean solid does, but requires an additional empirical constant.
Elastic response of rubber-like materials are often modelled based on the Mooney-Rivlin model.
- C. W. Macosko Rheology: principles, measurement and applications, VCH Publishers, 1994, ISBN 1-56081-579-5
Notes and References
- ↑ The characteristic polynomial of the linear operator corresponding to the second rank three-dimensional Finger tensor is usually written
In this article, the trace is written , the next coefficient is written , and the determinant would be written .