NSTAR provides a large array of nonlinear analysis capabilities that make it possible for you to analyze your models under real-life conditions. 



The key features of the NSTAR module are described under the following three categories: 

Nonlinear Behavior Capabilities:

Geometric nonlinearities that include effects of large deformations and large strains; (large deformation composite shell analysis is also available.) 
Material nonlinearities such as thermo-plasticity, large strain plasticity, large strain rubber behavior, creep, viscoelasticity, nonlinear elasticity, and wrinkling membrane. 
Models involving large deformation 2D/3D contact with or without friction; (Contact of bodies with geometric and material nonlinearities can also be considered.) 

Nonlinear Analysis Capabilities:

Nonlinear response under static loading conditions. 
Nonlinear (or Linear) step-by-step dynamic analysis (implicit or explicit techniques) for dynamic loading conditions and/or impact. 
Limit load analysis, post-limit-load analysis, thermal buckling, and snap-through/snap-back buckling. 
Nonlinear frequency analysis, nonlinear buckling analysis. 

Special Features:

Sparse solver technology for considerably faster solutions. 
Adaptive auto-stepping and Restart for ease of use and accuracy. 
Different solution controls such as force, displacement, and arc length. 
Evaluation of material constants from curve data. 
Evaluation of J-integrals for nonlinear models with cracks. 
Support of user-defined material models and user-defined creep models. 
Prescribed displacements and couplings in local coordinate systems suited for large deformation analyses.