Nonlinear Analysis Control 





Specify the iteration method and convergence conditions for performing a nonlinear analysis reflecting large displacement and material nonlinear analysis . The large displacement analysis can be applied to both general static analysis and construction stage analysis. Material nonlinear analysis can only be applied to static analysis. Prior to an analysis, specify the sequence of applying loads in Loading Sequence for Nonlinear Analysis, and define the convergence criteria for nonlinear analysis in Nonlinear Analysis Control. Specified loading sequence is effective only when NewtonRaphson is selected as the Iteration Method. Large displacement analysis and material nonlinear analysis can be performed on Truss, Plate, Plane Stress, Plane Strain, Axisymmetric, and Solid elements. Note Tensiononly/Compressiononly element will be changed to Truss element in Eigenvalue Analysis. 







From the Main Menu select Analysis > Analysis Control > Nonlinear. 





Nonlinear Type Select a type of nonlinear analysis Geometry Nonlinear: Geometric large displacement nonlinear analysis Material Nonlinear: Material plasticity static analysis Note 1 Following elements can be used in geometry nonlinear analysis and/or material nonlinear analysis.
(O : Analysis can be performed. / X : Analysis cannot be performed. / △ : Corresponding elements are considered as linear elements and then analysis can be performed.)
Note 2 Geometry nonlinear analysis and/or material nonlinear analysis cannot be performed for the items marked x.
Note 3 Analysis result is produced only at both I & J ends of elements in geometry nonlinear analysis.
Iteration Method Select the method of iteration. If NewtonRaphson is selected Number
of Load Steps Maximum
Number of Iterations/Load Step If ArcLength is selected Number of Increment Steps Maximum
Number of Iterations/Increment Step Initial
Force Ratio for Unit ArcLength (%) Note Real number (decimal) can be input.
Maximum Displacement Boundary Magnitude of maximum displacement
If DisplacementControl is selected Number
of Displacement Steps Maximum
Number of Iterations/Increment Step Master
Node Direction Maximum
Displacement Convergence Criteria Specify the basis on which to assess the convergence. Energy
Norm Displacement
Norm Force
Norm Note : Remove the conditions for a nonlinear analysis. Load Case Specific Nonlinear Analysis Control Data The above defined Iteration Method is applied individually by load cases. If the same iteration method is applied to all the load cases, this dialog box need not be used. Iteration Method Data
for NewtonRaphson/ArchLength/DisplacementControl Method Step: Number of Load Steps entered Load Factor: load factors for each increment 8 steps are generated in the Dialog box above in accordance with the Number of Load Steps entered. Load Factors can be userdifined, or autogenerated by clicking on the button. Note 1 When ArcLength Method (ALM) is used to solve the nonlinear equilibrium equation, a real number can be inputted into the "Initial Force Ratio for Unit ArcLength (%)" text box in Nonlinear Analysis Control.
Note 2 In nonlinear analysis, the sequence of applying loads can be defined in Loading Sequence for Nonlinear Analysis. Loading sequence can be used when NewtonRaphson and DisplacementControl are selected as Iteration Method. In one model, both DisplacementControl and NewtonRaphson iteration method can be used. However, the load case specified as NewtonRaphson iteration method must be applied in advance of the load case specifined as DisplacementControl method. 

