Also, from the analysis, the modified influence coefficients are found to be correlated to forward precession and imbalanced forces when the asymmetry of the bearings is considered.
Discoordination indices are therefore only indirect markers of (imbalanced) contractile force development and lack information on the ultimate consequences of dyssynchrony on the pressure-generating ability of the heart.
The non-linear forced response is studied in two ways: (1) using imbalance force; (2) using non-imbalance harmonic force.
By adjusting the orientations of the flaps in both systems, it is possible to create a counterforce which suppresses the imbalance force, reducing the vibration to a minimum.
Based on observations of the consistent trajectory of the centre of mass of a sloshing fluid, the imbalance force due to the displacement of the sloshing fluid is linked to the restoring force in the pendulum equation.
As opposed to the large majority of previous works on the subject, in which harvesters are excited at their bases by prescribed acceleration, herein the harvester is connected to a vibrating structure excited by an imbalance force.
The results of numerical simulations show that a successful implementation of this strategy could produce a significant reduction of the forces transmitted to the foundation by a machine subject to a rotating imbalance force or of the mean square acceleration in a car riding on a randomly profiled road.
Whereas the mass imbalance force can be directly computed, the aerodynamic imbalance forces need to be determined via, e.g., the Blade-Element-Momentum (BEM) method, a nonlinear procedure.
For the hardness-alternating formation, there are several phenomena: (1) part of the cutters will cut hard rock, these cutters will bear a large impact load, and the impact load can not only cause impact damage of cutters, but also reduce the stability of PDC bit; (2) DC bit will bear large lateral imbalance force, which lead the reverse circumnutation (whirling motion) of bit.
The random forces inflicted on the system are comparable to the harmonic imbalance forces, if the imbalance is not very significant.
The problem of parameter estimation, in a non-linear rotor-bearing system experiencing small residual imbalance forces along with random forces, is transformed into one of slowly varying parameters through the stochastic averaging procedure.
