MBSIM

Bulk Data Entry Defines the parameters for a multibody simulation.

Format

If TYPE = TRANS and ITYPE = DSTIFF

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM ID TYPE TTYPE TIME STYPE DELTA/

NSTEP

/

PRINCR
ITYPE DTOL H0 HMAX HMIN VTOLFAC MAXODR
DAEIDX DCNTOL DCRMXIT DCRMNIT DVCTRL DJACEVL DEVLEXP
DJACINI DINTPRL
If TYPE = TRANS and ITYPE = VSTIFF/MSTIFF/ABAM
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM ID TYPE TTYPE TIME STYPE DELTA/

NSTEP

/

PRINCR
ITYPE DTOL H0 HMAX HMIN VTOLFAC MAXODR
If TYPE = STATIC
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM ID TYPE TTYPE TIME STYPE DELTA/

NSTEP

/

PRINCR
KETOL/RESTOL DQTOL/FITOL NITER STBLT COMPDEL STTYPE

Example 1

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM 99 TRANS END 5.0 NSTEPS 250
VSTIFF 0.001 0.001 0.01 1000.0 5

Example 2

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM 99 TRANS END 5.0 NSTEPS 250
DSTIFF 0.001 0.001 1000.0 9
3 4 TRUE

Example 3

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MBSIM 91 STATIC
1.0e-6 0.0001 100

Definitions

Field Contents SI Unit Example
ID Unique identification number.

(Integer > 0)
TYPE Simulation type.
TRANS
Transient simulation type.
STATIC
Static simulation type.

No default
TTYPE Termination type. 2
END
DUR

No default
TIME Termination time or duration based on TTYPE.

(Real > 0.0) 2
STYPE Output step type.
DELTA
The next argument is expected to be a positive real value, and it is the output step time during the simulation run.
NSTEPS
The next argument is expected to be a positive integer value which will be the number of output steps during the simulation.
PRINCR
The next argument is expected to be a positive integer value which will be print increment. Solver will output at every intermediate print increment value. If PRINCR is set to 1, the solver will output intermediate results at every integrator step.

No default 2
DELTA Output time step.

(Real > 0.0) 2
NSTEPS Maximum number of time steps.

(Integer > 0) 2
ITYPE Integrator type.
ABAM
VSTIFF
MSTIFF
DSTIFF (Default)
DTOL Integrator tolerance.

Default = 0.001 (Real > 0.0)
H0 Initial time step for the integrator.

Default = 1e-8 (Real > 0.0)
HMAX Max step size the integrator is allowed to take.

Default = 0.01 (Real > 0.0)
HMIN Min step size the integrator is allowed to take.

Default = 1.0e-6 (Real > 0.0)
VTOLFAC A factor that multiplies DTOL to yield the error tolerance for velocity states.

Default = 1000 (Real > 0.0)
MAXODR The maximum order that the integrator is to take.

Default depends on ITYPE (Integer > 0)
DAEIDX The index of the DAE formulation.

Default = 3 (Integer > 0)
DCNTOL A tolerance on all algebraic constraint equations that the corrector must satisfy at convergence.

Default = 0.001 (Real > 0.0)
DCRMXIT The maximum number of iterations that the corrector is allowed to take to achieve convergence.

Default = 4 (Integer > 0)
DCRMNIT The minimum number of iterations that the corrector is allowed to take before it checks for corrector divergence.

Default = 1 (Integer > 0)
DVCTRL A logical flag that controls whether the velocity states are checked for local integration error at each step.
True
False

Default = True, if DAEIDX is 3; otherwise False
DJCEVL An attribute to control the frequency of evaluation of the Jacobian matrix during corrector iterations.

Default is determined by MotionSolve (Integer ≥ 0)
DEVLXP The number of integration steps after which the evaluation pattern defined by DJCEVL is ignored, and the default evaluation pattern is to be used.

Default = 0 (Integer ≥ 0)
DJACINI Controls the Jacobian matrix evaluation during corrector iterations.
0 (Default)
The integrator automatically determines when a new Jacobian is needed by examining the rate of convergence.
1
A new Jacobian is calculated at the first iteration.
2
A new Jacobian is calculated at the second iteration.
DINTRPL Specifies whether the integrator uses interpolation for the results at the output steps.
TRUE (Default)
The solver forces the integrator to integrate the states from start_time to end_time as specified in the <Simulate> block. The results are then interpolated at the requested output points.
FALSE
The solver does not place any restrictions on the integrator.
KETOL Maximum residual kinetic energy tolerance.

Default = 1.0e-5 (Real > 0.0) 3
RESTOL Maximum residual tolerance for force imbalance method.

Default = 1.0e-4 (Real > 0.0) 4
DQTOL Maximum coordinate difference tolerance.

Default = 0.001 (Real > 0.0) 3
FITOL Maximum force imbalance tolerance.

Default = 0.001 (Real > 0.0) 4
NITER Max number of iterations for static solution to converge.

Default = 50 (Integer > 1) 3
STBLT Specifies the fraction of the mass matrix that is to be added to the Jacobian to ensure that it is not singular.

Default = 1e-10 (Real) 6
COMPDEL Delta value used during compliance matrix calculation.

Default = 0.001 (Real) 6
STTYPE Static solver type. 5
FIM
The Force Imbalance Method.
MKM (Default)
The Maximum Kinetic Energy Attrition Method.

Comments

  1. Look for appropriate options based on the type of simulation specified.
  2. When the simulation type is static (STATIC), the solver will perform a static simulation if the termination type, termination time/duration, step type, and delta/nsteps are not provided. A quasi-static simulation will be performed if the information is provided.
  3. KETOL, DQTOL, and NITER are only applicable for STATIC simulation type.
  4. RESTOL, FITOL, and NITER are applicable for the force imbalance static method used for quasi-static solutions.
  5. When quasi-static simulation is requested (STATIC with termination time), the STTYPE option is ignored and the quasi-static simulation will be performed using the force imbalance method.
  6. For further information, refer to Parameters: Transient Solver and Parameters: Static Solver in the MotionSolve Reference Guide.
  7. This card is represented as a load collector in HyperMesh.