/IMPL/QSTAT

Engine Keyword

/IMPL/QSTAT - Quasi-static Implicit Solution

Description

Quasi-static implicit solution will be computed.

Format

/IMPL/QSTAT

Comments

When quasi-static has been used, positive definite property of stiffness matrix will be reinforced by including the inertia matrix. The extra stiffness is in function of masses, inertia and the time-step. Smaller the time-step, more change will be affected to the stiffness. A scale factor can be defined by /IMPL/QSTAT/DTSCAL to scale this adding matrix (inversely square proportional just like time-step: for example, a scale factor of 0.1 will increase 100 times the inerta stiffness). For nonlinear analysis, this will only modify the convergence speed without changing the result; for linear analysis, time step (one step) should be chosen carefully (not too small to significantly change the result and not too big to keep the matrix positive definite). This option is quite suitable for the model in which some free pieces are connected only by contact during simulation and failed with other analysis types. Linear quasi-static analysis can also be used for model checking of high level (can be also used for explicit analysis), with a time-step not too big, the result can be always found, whether the model is well constrained or not.

2.	This option can be combined with /IMPL/LINEAR or /IMPL/NONLIN.