Please help me about this problem. It made me crazy. I can't understand how has the equation (8) obtained??? I attached it.
so I'm sorry about my poor English.
Tank u very much
Thank u about your respone.
But we can ignore equations (1),(2) and just use of another equations. Please just use of equations (3),(4),(5),(6),(7) and (8). and sigma is a constant. and f is a yield function in plasticity. In fact, f represents a surface in the space of (sigma1,sigma2). I have uploaded piece of this paper for u, maybe that help.
Link of paper: [COLOR="rgb(0, 0, 0)"]Document1.pdf - 4shared.com - document sharing - download[/COLOR]
Thank u again