Using such graphs, it is possible to check the best optimization stages for each damping ratio
considered, and to show the best optimization points throughout the process.
The objective of modeling the damping controller is to enhance the damping ratio
of the poorly-damped or unstable electromechanical modes of oscillation, which can be achieved through designing of a damping controller that provides a pure damping torque.
Often a damping ratio
is assumed when performing the FE structural analysis.
The controller parameter space is obtained considering D-stability requirements shown in Figure 11 for the two free coefficients of a PD controller as the proportional gain [k.sub.P,i] and the derivative gain [k.sub.D,i] Figure 11 can be interpreted as constraining the poles of the closed loop PD-controlled system to lie in the D-Stable region of the desired settling time ([[partial derivative].sub.1]), a desired minimum damping ratio
([[partial derivative].sub.2]) and the desired maximum bandwidth ([[partial derivative].sub.3]).
The Model 7264H 1,000g piezoresistive accelerometer with a natural frequency [greater than or equal to]19 kHz uses gas damping with a damping ratio
between 0.4 and 0.85 to minimize ringing in shock applications.
Two of the necessary parameters for the study of dynamic behavior of an object are the modulus of elasticity and the damping ratio
; and the results of this study will aid in the development of harvesters using mechanical vibration.
This study presents predictive models for estimating normalized shear modulus and damping ratio
of three compacted remodeled rockfill materials using modified hyperbolic and nonlinear multiple regression methods.
The generalized inverse system parameters ([a.sub.10], [a.sub.11], [a.sub.20], [a.sub.21]) are set to make the damping ratio
([xi]) of this composite subsystem close to 0.7.
However, the relative variation in each mode damping ratio
is larger than that for frequencies.
The variation curve of transmissibility coefficient T with the frequency ratio [beta] for discrete values of the damping ratio
[xi] is shown in Figure 2.
The weakly damped electromechanical mode will have minimum value of damping ratio
[Min([xi]i)] among all the damping ratios
of the system.
Since the electromechanical modes are generally poorly damped and dominate the time response of the system, it is expected that by maximizing the minimum damping ratio
, we could simultaneously stabilize the family of the system models over the given range of operating conditions and ensure that the closed-loop system is stable -.