Nonlinear analysis

 

When the setting per material is done, user reinforcement is inputted or not and non-linear combination is defined then non-linear analysis can be run. Significant factor for finite element calculation, mainly for nonlinear analysis is number of 1D mesh element and mesh size for 2D member. After several kind of testing we recommend to set:

• Average size of 2D mesh elements = h/2 for steel fibre reinforced concrete
• Average size of 2D mesh elements =h for reinforced concrete and for combined reinforcement (steel fibre reinforced concrete + standard reinforcement)
• Average number of 1D mesh elements

 

The mesh size is always a significant factor for Finite Element calculation method and mainly for nonlinear analysis. mesh size = h/2 for steel fibre reinforced concrete and mesh size = h for combined reinforcement (steel fibre reinforced concrete + standard reinforcement) .

There is used standard Newton-Raphson method for solving of this physical nonlinear problem with recommendation of 10 increments of loads and 500 iterations in each load increment

When load is too high and no equilibrium is found in certain increment of load with reaching of maximum number of iterations, the user is informed about this with warning .

Besides, the nonlinear calculation uses very efficient damage material model called Mazars model [3] Mazars. This material model is very well applicable for material diagram with peaks and descending stress-strain diagrams.