Nonlinear solution procedure

True structural behaviour is inherently nonlinear, characterised by non-proportional variation of displacements with loading, particularly in the presence of large displacements or material nonlinearities. Hence, in SeismoStruct, all analyses (with the obvious exception of eigenvalue procedures and Response Spectrum Analysis) are treated as potentially nonlinear, implying the use of an incremental iterative solution procedure whereby loads are applied in pre-defined increments, equilibrated through an iterative procedure.

• Incremental iterative algorithm
• Automatic adjustment of load increment or time-step
• Convergence criteria
• Numerical instability, divergence and iteration prediction