Subroutine Type

Modeling

Definition

Used to compute displacement, velocity, or acceleration for a Motion entity.

Use

User-defined motion using displacement and computed in a MOTSUB:

<Motion_Joint

    id                  = "301001"

    type                = "USERSUB"

    val_type            = "D"

    usrsub_param_string = "USER(5,2)"

    usrsub_dll_name     = "NULL"

    joint_id            = "301002"

    joint_type          = "R"

    motion_type         = "R"

    ic_disp             = "0."

    ic_vel              = "0."

 />

Calling Syntax

Fortran

SUBROUTINE MOTSUB (ID, TIME, PAR, NPAR, IORD, IFLAG, VALUE)

C

void STDCALL MOTSUB (ID, TIME, PAR, NPAR, IORD, IFLAG, VALUE)

Python

def MOTSUB(id, time, par, npar, iord, iflag):

    return value

MATLAB

function value = MOTSUB(id, time, par, npar, iord, iflag)

Input Arguments

[integer] ID

The user-defined motion element identifier.

[double precision] TIME

The current simulation time.

[double precision] PAR

An array that contains the constant arguments from the list provided in the user-defined statement.

[integer] NPAR

The number of entries in the PAR array.

[integer] IORD

The order of the time derivative.

0

Displacement.

1

Velocity.

2

Acceleration.

[logical] IFLAG

The initialization flag.

Output Values

[double precision] VALUE

The output value that contains the computed displacement, velocity, or acceleration of the I marker with respect to the J marker.

Example

def MOTSUB(id, time, par, npar, iord, iflag):

    if par[0]==100001:    

        if iflag!=0:

            return -1.0

        if iord==0:

            value = par[1]*pow(time,par[2])

        elif iord==1:

            value = par[1]*par[2]*pow(time,(par[2]-1.0))

        elif iord==2:

            value = par[1]*par[2]*(par[2]-1.0)*pow(time,(par[2]-2.0))

    else:

            value = 0.0

    return value