Theory for Single-Port Components
The equations for all the single-port components, which are also known as the terminals, are described below:
•
Theory for Fixed Node
•
Theory for Displacement Node
•
Theory for Velocity Node
•
Theory for Acceleration Node
•
Theory for Free node
•
Theory for Force Node
•
Theory for Impedance Node
Theory for Fixed Node
Figure 5-8:
A fixed node connected at node p1.
The following equation prescribes the node displacement,
u
p
1
:
Theory for Displacement Node
Figure 5-9:
A displacement node connected at node p1.
The following equation prescribes the node displacement,
u
p
1
:
Frequency-Domain and Eigenfrequency Studies
Time-Dependent and Stationary Studies
Here
u
p
10
is the prescribed displacement value and
ϕ
is the phase angle.
Sometimes, a parallelly connected spring-damper system with one end fixed and other end with motion prescribed using
Displacement Node
shows convergence issues. For such cases, use one of the following alternatives:
•
Use
Velocity Node
instead of
Displacement Node
to prescribe the equivalent velocity at the end.
•
Increase the scaling of force variables.
•
For-time dependent studies, modify time-dependent solver settings by setting
Error estimation
in the
Time Stepping
section to
Exclude algebraic
.
Theory for Velocity Node
Figure 5-10:
A velocity node connected at node p1.
The following equation prescribes the node displacement,
u
p
1
, given that
v
p
1
is the prescribed velocity value:
Frequency-Domain and Eigenfrequency Studies
Time-Dependent Studies
Stationary Studies
If the displacement is set to free:
If the displacement is set to constrained:
Theory for Acceleration Node
Figure 5-11:
An acceleration node connected at node p1.
The following equation prescribes the node displacement,
u
p
1
, given that
a
p
1
is the prescribed acceleration value:
Frequency-Domain and Eigenfrequency Studies
Time-Dependent Studies
Stationary Studies
If the displacement is set to free:
If the displacement is set to constrained:
Theory for Free node
Figure 5-12:
A free node connected at node p1.
The following equation prescribes the nodal force,
f
p
1
:
Theory for Force Node
Figure 5-13:
A force node connected at node p1.
The following equation prescribes the nodal force,
f
p
1
:
Frequency-Domain and Eigenfrequency Studies
Time-Dependent and Stationary Studies
Here
f
p
10
is the prescribed force value and
ϕ
is the phase angle.
Theory for Impedance Node
Figure 5-14:
An impedance node connected at node p1.
The following equation relates the nodal force (
f
p
1
) and node displacement (
u
p
1
):
Frequency-Domain and Eigenfrequency Studies
Time-Dependent and Stationary Studies
Here
Z
is the prescribed impedance value.
