I am wondering if the fact that "large deformation effect resulting in large strains has not been implemented [in the SOL401]" (Multi-Step Nonlinear User’s Guide p. 9) will change in the near future or if implementing large deformation effect is planned for the next releases.
Also I am wondering why there is a "large displacement" option in the solver option.
thanks for your time
Large Deformation/Large Displacement refer to geometric nonlinearity. They are macro level terms meaning that the node locations have changed significantly enough through the analysis that the stiffness matrix needs to be reformed based on the updated node coordinates. It also means that the follower forces in the load vector may be updated (i.e. normal surface pressures updated based on rotated surface normal directions). There are also other effects that may be considered in particular analyses (spin softening, etc.)
Large strain is a more micro level term meaning that an element formulation is appropriate for large values of strain. These are localized large strains at the element level. This is an aspect of material nonlinearity.
You can have a geometric nonlinear analysis with no material nonlinearities where the overall structure deformation is significant. SOL 401 can do this.
You can have a geometric nonlinear analysis with material nonlinearities where the overall structure deformation is significant, but local element strains remain small. SOL 401 can do this also.
You can have a material nonlinear analysis with no geometric nonlinearities where the local element strains remain small. SOL 401 can do this also.