Self-synchronization theory of a dual mass vibrating system driven by two coupled exciters. Part 2: Numeric analysis

The coupling dynamic characteristics of the vibrating system with dual mass are analyzed quantitatively. Both the load torque and the coupling torque have three items. Two of them are concerned with the translation of the system, and the third item is related to the rotation of the system. Through numerical computation, the effects of translation and rotation in the system are considered in relation to the self-synchronization. The phase difference of two eccentric blocks is caused by the difference of the rated revolution of two motors. The stability of the synchronous operation is dependent on the structural parameters of the system, such as the mass ratio of two eccentric blocks and the distance between motor and centroid of the rigid frame. Simulation is carried out to verify that the system can be synchronized and the model can ensure the stability of synchronization if the parameters of the system meet the conditions of synchronous implementation and stability. Simulations are also performed for the case of self-synchronization of two motors with different rated revolutions

Self-synchronization theory of a dual mass vibrating system driven by two coupled exciters. Part 1: Theoretical analysis

A vibration model is proposed and analyzed dynamically to study the selfsynchronization theory of dual-mass vibration system. The differential equations of systematic motion are derived by applying Lagrange’s equations. As two uncertain parameters, the coefficients of instantaneous change of average angular velocity and the phase difference of two exciters are introduced to derive the coupling equations of angular velocity of the two exciters. The conditions of synchronous implementation and stability are derived by utilizing the modified small parameter average method treated as non-dimension to the parameters. The swing of the vibration model plays a major role in the self-synchronization of two motors. The mass ratio of two eccentric blocks has an effect on the stability of synchronous operation

Active Vibration Suppression Based on Piezoelectric Actuator

The piezoelectric constitutive equation states that the inverse piezoelectric effect can convert electrical energy into mechanical energy, resulting in small displacement and force changes with high resolution. The piezoelectric actuator based on inverse piezoelectric effect has an excellent performance in active vibration suppression because of its high frequency response, high positioning accuracy, and large output force. A new active-passive composite vibration suppression system can be formed by cascading it with passive vibration isolation elements in series and parallel. On this basis, by adding different control algorithms and control loops, such as the Sky-Hook damping feedback control algorithm and adaptive feedforward control algorithm, different vibration control effects can be realized

Self-synchronization theory of a dual mass vibrating system driven by two coupled exciters. Part 1: Theoretical analysis

A vibration model is proposed and analyzed dynamically to study the selfsynchronization theory of dual-mass vibration system. The differential equations of systematic motion are derived by applying Lagrange’s equations. As two uncertain parameters, the coefficients of instantaneous change of average angular velocity and the phase difference of two exciters are introduced to derive the coupling equations of angular velocity of the two exciters. The conditions of synchronous implementation and stability are derived by utilizing the modified small parameter average method treated as non-dimension to the parameters. The swing of the vibration model plays a major role in the self-synchronization of two motors. The mass ratio of two eccentric blocks has an effect on the stability of synchronous operation

A Human Intestinal Infection Caused by a Novel Non-O1/O139 Vibrio cholerae Genotype and Its Dissemination Along the River

Non-O1/O139 Vibrio cholerae is increasingly reported in the clinical settings. However, intestinal infections via the consumption of non-O1/O139 V. cholerae-carrying seafood are rarely documented in China. In this study, we reported a case of mild watery diarrhea in a young male, caused by non-O1/O139 V. cholerae in the downstream of Liaohe River. Epidemiological investigation showed that this intestinal infection potentially associated with the raw consumption of mollusc. Prior to this finding, we conducted a 6-month pathogen surveillance of three locations along the Liaohe River and identified three environmental non-O1/O139 V. cholerae strains. To confirm the epidemiological links between clinical and environmental strains, high-resolution genomic typing was employed and revealed that V. cholerae isolated from human stool sample was genomically related to the one found in local mollusc and shared a common ancestor with other environmental strains obtained in the upstream sites of the Liaohe River. This fact suggests that the river is a natural reservoir for non-O1/O139 V. cholerae which poses a potential threat to the public health. In summary, our results deepened the insights on the transmission of non-pandemic V. cholerae strains and underscored the significance of genomic surveillance for drinking water along the river sites