|
(i) The given initial values include , , , , material and iterative controlling parameters; |
| (ii) According to the acting loads , execute iteration within th loading step, to find displacement increments |
| by (20) until achieving convergence: |
| (1) For the th iteration: |
| We assume ; ; and , then execute the iterative loops by (20): |
| ① Compute the strain increments , stresses , yield function value , and the other coefficients. |
| ② Compute the plastic parameter , and determine the stress state: |
| If , the stress is located in the plastic area; if , then the stress is in the elastic area. |
| ③ Update stiffness matrix by the following regulations: |
| (a) In the elastic area, eliminate the terms containing A in (20). |
| (b) In the plastic area, compute by (13) and (18). |
| ④ Solve by (20), calculate . |
| ⑤ Determine whether or not err is less than , ( in this paper). |
| If not, repeat Steps ①④, and conduct the th iteration, until achieving convergence. Then return to Step (2). |
| (2) Re-compute the plastic parameter by the displacements at the final iteration, determine the stress state, |
| compute the total stresses by (21), as well as inner variable , plastic strains, and so on. |
| (iii) Repeat Step (ii), continue the computation of the next load step, determine whether or not failure takes place, |
| and obtain the ultimate load. |
