CMROTATE, CM_Name, ROTATX, ROTATY, ROTATZ, X1, Y1, Z1, X2, Y2, Z2
Specifies the rotational velocity of an element component
in a brake squeal analysis.
CM_NameThe name of the element component.
ROTATX, ROTATY, ROTATZIf the X2, Y2, Z2 fields are not defined, ROTATX, ROTATY, and ROTATZ specify the components of the rotational angle
vector in the global Cartesian X, Y, Z directions.
If
the X2, Y2, Z2 fields are defined, only ROTATX is required. ROTATX specifies the scalar
rotational velocity about the rotational axis. The rotational direction
of ROTATX is designated either positive
or negative, and is determined by the “right hand rule.”
X1, Y1, Z1If the X2, Y2, Z2 fields are defined, X1, Y1, and Z1 define the coordinates of the beginning point of
the rotational axis vector. Otherwise, X1, Y1, and Z1 are the coordinates of a point through which the rotational axis
passes.
X2, Y2, Z2The coordinates of the end point of the rotational axis vector.
The CMROTATE command specifies the rotational
motion velocity components ROTATX, ROTATY, and ROTATZ of an
element component CM_Name about a user-defined
rotational axis. The rotational axis can be defined either as a vector
passing through a single point or a vector connecting two points. CMROTATE can be used in static analyses (ANTYPE,STATIC) and modal analyses (ANTYPE,MODAL).
This command sets the constant rotational velocity on the nodes of the specified element component, despite any deformation at the nodes. This feature is primarily used for generating sliding contact at frictional contact interfaces in a brake squeal analysis. This type of analysis typically involves surface-to-surface contact between the brake pad and the rotating disk. The applicable contact elements, therefore, are CONTA173, CONTA174, and CONTA175.
A brake squeal analysis generally involves a linear perturbation modal analysis subsequent to a large-deformation static analysis with the Newton-Raphson option set as NROPT,UNSYM. Therefore, CMROTATE is not applicable for multiple load step solves using the LSSOLVE command.
This command is also valid in PREP7.