In simple terms, one should use nonlinear analysis in situations involving one or more of the following behaviors:
1) large displacement, but strains are small as in large bending of thin parts
2) bodies that are not touching initially, come into contact during analysis
4) large elastic strains - rubber etc.
5) loads are changing (with psuedo time) - loading and unloading
Some trivial cases:
In Simulation 2009, linear static solver automatically detects if large displacement should be turned.
When you run a static analysis and von Mises stress plot shows that maximum is above yield point, then you need to rn either nonlinear analysis or turn on large displacement in static study if any other types of behavior listed above are absent.
Linear analysis assumes a linear relationship between stress and strain. Non linear analsis allows you to enter a stress strain relationship that is non linear. This occurs with plastics or where you have plastic failure of steel.
have you formula or morre detail data and graphic that can give me more details about this ?
OK, I have got the main idea of differences.
I wish for more details about the data and formula....
That is a very large question. If you really want to know the answer you should take some FEA courses, read a book, or read the course notes in the links below. That will give you a start in understanding nonlinear FEA. I hope this helps.
Wow, thats very detail guide....
Thanks every one on helping me more understand linier vs nonlinier analysis.
Can I ask why you want this information? What are you wanting to design?