Ramberg-Osgood equation

The above-mentioned thermomechanical models only consider the elastic behavior of materials. Boyd et al. [13] reported on compression creep rapture tests performed on unidirectional laminates of E-glass/vinylester composites subjected to a combined compressive load and one-sided heating. Models were developed to describe the thermoviscoelasticity of the material as a function of time and temperature. In their work, the temperature-dependent mechanical properties were determined by fitting the Ramberg-Osgood equations and the temperature profiles were estimated by a transient 2D thermal analysis in ANSYS 9.0. 

Fig. 3.16. True stress-strain curve of AlMgSi 1 with fitted Ramberg-Osgood equation. The used parameters are E = 66.2 GPa, K = 327 MPa, n = 0.10...

Ramberg-Osgood-type equations were also used to describe shear behavior of structural adhesives. Zabora et al. (1971) used a rate-dependent form of the Ramberg-Osgood equation to describe the shear behavior of structural adhesives in the bonded form. 

To ease the calculation of plastic deformations, stress-strain curves are frequently approximated using simple equations. One commonly used example is the Ramberg-Osgood law... 

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