TSTEPE

Bulk Data Entry Defines time step parameters for control and intervals at which a solution will be generated and output in explicit analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TSTEPE SID TYPE DTFAC DTMIN DTMAX        

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TSTEPE 2 ELEM .9 1.0-7 1.0.-2        

Definitions

Field Contents SI Unit Example
SID Set identification number.

No default (Integer > 0)

  
TYPE Explicit time step control types. 2
ELEM (Default)
Minimum stable elemental time increments. The minimum stable time increment for each element is calculated and then the minimum is chosen as the stable global time increment.
NODA
Minimum stable nodal time increments. The minimum stable time increment for each node is calculated and then the minimum is chosen as the stable global time increment.
  
DFAC Scale factor for stable time increments. OptiStruct will scale the global stable time increment computed based on the time step control type chosen in TYPE field.

Default = 0.9 (Real > 0.0)

  
DTMIN Minimum allowed time increment. This option is only supported for TYPE=NODA. If the number is larger than the computed critical time increment (DTFAC times the global stable time increment), mass scaling will be used.

In case mass scaling is activated, the new minimum time increment is DTMIN. For mass scaling, mass is added every time the critical time increment is less than DTMIN. 3

Default = 0.0 (Real ≥ 0.0)

  
DTMAX Maximum allowed time increment.

No default (Real > 0.0)

  

Comments

  1. TSTEPE entries must be selected by the Subcase Information command TSTEPE= SID.
  2. When calculating nodal time step, nodal stiffness includes contribution from contact nodes. Increasing contact penalty could decrease time increment and increase number of cycles.
  3. Mass scaling is only applied to nodes for which the scaled critical time step (scaled by DTFAC) falls below DTMIN.