CONSTANT VELOCITY

Connection type CONSTANT VELOCITY provides the rotational part of connection type CVJOINT. It cannot be used in two-dimensional or axisymmetric analysis. Furthermore, the connection type does not have available components of relative motion. To include connector behavior in flexural motion, use connection type FLEXION-TORSION with the torsion angle set to zero.

This connection type models physical connectors that under certain conditions transmit a constant spinning velocity about misaligned shafts.

Related Topics
Connector elements
Connector element library
In Other Guides
*CONNECTOR BEHAVIOR
*CONNECTOR SECTION

ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE

Description

Figure 1. Connection type CONSTANT VELOCITY.

The shaft direction at node a is e3a, and the shaft direction at node b is e3b. The constant velocity constraint is stated as follows. In any configuration there are two unit length orthogonal vectors b1 and b2 in the plane perpendicular to the shaft at node b. These vectors can be written

b1=cosβe1b+sinβe2b    and    b2=-sinβe1b+cosβe2b.

The angle β is chosen such that

e1ab2=e2ab1.

The constant velocity constraint requires that the angle β is constant at all times. The constant velocity constraint is equivalent to constraining the torsion angle to be constant in a FLEXION-TORSION connection.

The name “constant velocity” for this connection type derives from the following property. If the angular velocities of the two shafts, wa and wb, have components only along each shaft, respectively, and in the direction of the normal to the plane containing the two shafts (that is, along the e3b×e3a direction), the components of angular velocity along the respective shaft directions are equal:

wae3a=wbe3b.

Hence, the “spinning” angular velocity component is the same about each shaft.

The constraint moment imposing the constant velocity constraint has a single component about the average shaft direction e3a+e3b and is written

m¯=m2(e3a+e3b)e3a+e3b.

Summary

CONSTANT VELOCITY
Basic, assembled, or complex: Basic
Kinematic constraints: e1ab2=e2ab1
Constraint moment output: m2
Available components: None
Kinetic moment output: None
Orientation at a: Required
Orientation at b: Optional
Connector stops: None
Constitutive reference angles: None
Predefined friction parameters: None
Contact force for predefined friction: None