Mapdl.acel(acel_x='', acel_y='', acel_z='', **kwargs)

Specifies the linear acceleration of the global Cartesian reference

APDL Command: ACEL frame for the analysis.

acel_x, acel_y, acel_z

Linear acceleration of the reference frame along global Cartesian X, Y, and Z axes, respectively.


In the absence of any other loads or supports, the acceleration of the structure in each of the global Cartesian (X, Y, and Z) axes would be equal in magnitude but opposite in sign to that applied in the ACEL command. Thus, to simulate gravity (by using inertial effects), accelerate the reference frame with an ACEL command in the direction opposite to gravity.

You can define the acceleration for the following analyses types:


Harmonic (ANTYPE,HARMIC), full or mode-superposition method

Transient (ANTYPE,TRANS)

Substructure (ANTYPE,SUBSTR).

For all transient dynamic (ANTYPE,TRANS) analyses, accelerations are combined with the element mass matrices to form a body force load vector term. The element mass matrix may be formed from a mass input constant or from a nonzero density (DENS) property, depending upon the element type.

For analysis type ANTYPE,HARMIC, the acceleration is assumed to be the real component with a zero imaginary component.

Units of acceleration and mass must be consistent to give a product of force units.

The ACEL command supports tabular boundary conditions (%TABNAME_X%, %TABNAME_Y%, and %TABNAME_Z%) for ACEL_X, ACEL_Y, and ACEL_Z input values (*DIM) as a function of both time and frequency for full transient and harmonic analyses.

Related commands for rotational effects are CMACEL, CGLOC, CGOMGA, DCGOMG, DOMEGA, OMEGA, CMOMEGA, and CMDOMEGA.

See Analysis Tools in the Mechanical APDL Theory Reference for more information.

This command is also valid in /PREP7.


Set global y-acceleration to 9.81

>>> mapdl.acel(acel_y=9.81)