Dynamic Relaxation: Modelling implications

Limitations

The following modelling options are not allowed when analysing with the dynamic relaxation nonlinear solver:

• Element offsets
• 1D Element section profile offsets
• 2D Elements:
  • Quad8 and Tri6 elements
  • Flat Plate and Curved Shell 2D properties
  • Property offsets and Reference Surface other than Centre
• 3D Elements
• Links:
  • custom
• Rigid Constraints:
  • x plate
  • y plate
  • z plate
  • x plate (pin)
  • y plate (pin)
  • z plate (pin)
  • custom

Properties

Materials – To take account of material nonlinearity, Material Properties with a yield stress can be defined using the materials wizard. The user defined materials are assigned to the section in the selection/numeric material field of the Section table.

Elements - Cable elements can behave as Sliding cable elements as well as Normal with the nonlinear analysis dynamic relaxation solver. See Element Types for more information

Cases

As the principle of superposition is not valid for nonlinear behaviour results from different analyses must not be added together. To mitigate this an analysis can be performed in steps with loads being applied incrementally during the analysis and the intermediate results stored. These incremental load options are offered by the Analysis Wizard.

Dynamic data

Although the solver uses a method called dynamic relaxation, the nonlinear options cannot be used to study the dynamic behaviour of a structure. Any data relating to dynamic analysis included in the model will be ignored during GsRelax analysis.