Plastic analysis~inelastic analysis-non-linear analysis
Plastic analysis~inelastic analysis-non-linear analysis
(OP)
I am just asking for my own learning. After crossing elastic limit, the stress and strain does not remain linear, I guess, we get more strain or even continuous increase in strain under same load. All three terms to me address same "one' issue or there is difference?






RE: Plastic analysis~inelastic analysis-non-linear analysis
RE: Plastic analysis~inelastic analysis-non-linear analysis
RE: Plastic analysis~inelastic analysis-non-linear analysis
RE: Plastic analysis~inelastic analysis-non-linear analysis
Dik
RE: Plastic analysis~inelastic analysis-non-linear analysis
material non-linearity is easy ... stress/strain beyond yield, the material is no longer linear elastic.
geometry non-linearity is when the structure stops responding to external load in a linear manner. your example of plastic hinges is one case ... the beam locally yields, goes plastic, but the beam can continue to react additional load ... the analysis of the beam changes for the standard beam to one with a plastic hinge. shear buckling of a web is another ... initially the web reacts the applied shear with in-plane shear stresses, but after it buckles, the sher is reacted by tension loads along the buckles. there are many of examples of non-linearity.
RE: Plastic analysis~inelastic analysis-non-linear analysis
Non-Linear Analysis:
Any form of analysis in which the force displacement relationship is expected to be non-linear. The main sub-categories of non-linear analysis would be Geometrically non-linear analysis and materially non-linear analysis.
Geometrically non-linear analysis:
An analysis where the deformation of the structure changes the stiffness properties of the structure. Normally, this is within the context of a P-Delta analysis. However, there are more complex behaviors that would also fall under this category (large deflection theory, catenary cables, fabric structures, et cetera).
In-Elastic analysis:
A form of material non-linear analysis where material non-linearity is accounted for from within the analysis itself. The material backbone curve in this case could be elasto-plastic, or could be more complex.
Plastic analysis:
To me this is really a sub-set of in-elastic design where the in-elastic behavior is usually associated with the plastic hinging of a moment frame.... Therefore, we're usually talking about an elasto-plastic material curve.