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As a continuous work of the previous literatures, a special dynamical model with one cylindrical roller driven by a single exciter and one outer ring, is taken for example to explore the vibratory synchronization transmission (VST) of the system considering sliding dry friction in this paper. The motion differential equations of the system, are given firstly. Using the average method, the theory condition of implementing VST is obtained. The VST characteristics are qualitatively discussed in numerical, which are further quantitatively verified by simulations. It is shown that, the vibration amplitudes of the roller in the horizontal and vertical directions are basically identical, and less affected by the friction coefficient, but the stable phase difference between the exciter and the outer ring is affected too much by it. Based on the present work, some new types of vibrating equipments, such as vibrating crushers/mills, can be designed.

The synchronization and stability of two unbalanced rotors (URs) separately driven by induction motors rotating in opposite directions, in a new mechanism system with four rigid frames (RFs), are investigated in present work. Applying Lagrange’s equation, the differential equations of motion of the system are deduced. The criteria of synchronization and stability of the synchronous states are derived analytically by using the average method and Hamilton’s principle, respectively. Based on the theoretical results, the coupling dynamic characteristics of the system are given by numeric, it is shown that the abilities of synchronization and stability, are the best under the condition that the parameters of the system are completely symmetrical. The stable states and the corresponding motion types of the system in different resonant regions, are clarified in detail. A Runge-Kutta simulation routine is employed to verify the validity of the theoretical results, as well as the feasibility of the used theory method. The selecting principle of the stable region with zero phase difference for the two URs, can provide a novel reference for designing a new type of vibrating feeder with the anti-blocking function in engineering.

This paper studies the mesh characteristics and vibration responses of a gear system with crack and spalling faults using different modeling methods. These modeling methods for the time-varying mesh stiffness (TVMS) include Yang's method, Tian's method and Liang's method which can not consider the effect of the fillet foundation stiffness, Zhou's method, Wan's method, two methods proposed by Ma and finite element method which include the effect of the fillet foundation stiffness. The effects of the crack and spalling are introduced into these models to calculate the TVMS for gear pairs with faults, and TVMS are compared based on these methods. By combining the TVMS with a two-dimensional lumped mass model of a gear system, the system vibration responses are compared using these modeling methods. The comparison results show that the fillet foundation stiffness has an important influence on the TVMS and vibration responses of the gear systems. Moreover, the error of repeated calculation of the fillet foundation stiffness must be revised.

Multi-layer integrated neural networks evaluation model of synthesis quality of the products is founded based on the information fusion theory. Quality of the products are synthetically evaluated using this model, moreover design method is also evaluated and verified, judgment of product performance and grade, as well as performance difference of the products in structural performance, service behavior and processing property. Scientific decision basis for evaluating and improving overall quality of the products is offered.

The synchronous mechanism of the phase for the vibratory machine with twin-motor drives rotating in the same direction is discussed by the virtue of the force analysis for the eccentric lumps and computer simulations in this paper. The observer of the difference between the two eccentric lumps is designed by using the two acceleration signs measured from the two symmetrical positions in the machine body. A PI controller is used to control the phase difference between the two eccentric lumps to realize the phase synchronization. The computer simulations are carried out to verify the effectiveness of the proposed scheme.

In this paper, according to the serious vibration and noise problem of Roots blower and based on the vibration energy transmission, a simplified dynamics model was set up which consist of five sub-structures such as rotor, bearing, box, vibration isolator and flexible foundation. The Lim model of elastic bearing was used, the rotor shaft and box were considered as rigid body, and the foundation was simplified a flexible sheet. The dynamic transferring matrix of blower sub-structure were derived using the method of component mobility, and then a spatial flexible couple dynamics model was established. As an example, the vibration characteristics of Roots blower were studid with the power flow method, and the numerical calculation and simulation of a sample were carried out. The analysis results showed that the influence of structural parameters, such as bearing stiffness, isolator stiffness, foundation stiffness and box mass, were more distinctly on the dynamics characteristics of Roots blower, which paid an important theory base for structure optimization and dynamic design.

In practical rotor systems, rotor-stator rub-impact may occur because crack fault causes the increase of vibration amplitude, which is called coupling fault with crack and rub-impact. The vibration signal is non-stationary due to the strong nonlinear characteristics of the coupling fault. In this paper, a rotor test rig was designed to research on nonlinear vibration characteristics of rotor systems with this fault. Some meticulous experiments were performed to simulate crack fault, rub-impact fault and coupling fault of both. The vibration signals were collected in the process of speed up-down running. The rough time-frequency features are extracted by spectrum cascade. For extracting the fault features better, the wavelet time-frequency method is adopted to accurately analyze the local unstable signal. The results show that the fault features can be well extracted by combining the two methods.

Bases on the virtual prototyping technology, a CAX integrated analysis environment in the PC platform is built. By the CAX, a simulation model of crankshaft system of internal combustion engine is built .The model is then used to analyze the kinematics and dynamics characteristics of some type crankshaft system. Through comparing the data of simulation result with that of classic literature, the virtual prototyping technology model is testified to reasonable and accurate. Then the real-time boundary load is achieved when the crankshaft is considered as flexible to simulate. Further more a transient dynamic response analysis is done on the crankshaft, its stress and deformation in the work cycle is gotten, then its dangerous part is also achieved. The simulation result provides a theory reference and basis for the crankshaft optimum design.

Aiming at oil-film instability fault often occurring in the project, fault simulation experiment was simulated by using a rotor test rig, and vibration signals of two groups were collected by adjusting thickness of disc and shaft length. Fault features were extracted by using spectrum cascades, reassigned wavelet scalograms and rotor trajectories. Some new interesting features are obtained by feature analysis and fault mechanism corresponding to theses features is explained. The results will provide theoretical references for diagnosing this kind of fault.

It analyzed connotation of generalized product quality, and established target system of generalized product quality, that is product index system of full function and whole performance including structural performance, operating performance and technological performance. Taking a new self-synchronous vibration screen as an example, it evaluated comprehensively generalized product quality by using fuzzy Analytic Hierarchy Process. Comparing with analytic hierarchy process, this method simplifies the people’s complex degree of relative importance to judgment target, and realizes quantitative conversion by means of fuzzy judgment matrix, so evaluation result possesses superior reliability.

A nonlinear dynamic model of rub-impact rotor-bearing system with slowly varying mass was set up. The periodic solution of system was analyzed by continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, and the stability of system periodic motion and unsteady law are discussed by Floquet theory. There exist periodic, quasi-periodic and chaotic motions in the response of the rub-impact rotor-bearing system with slowly varying mass. The unstable form of it is saddle-node bifurcation. There are periodic-doubling bifurcation and saddle-node bifurcation at different rotate speed. In the region of double critical rotate speed, the main motion of the system is quasi-periodic motion. The conclusions provide theoretic basis reference for the fault diagnosis of the rotor-bearing system.

In order to investigate the differences in the results which are obtained by analyzing the same acoustic emission signal with different wavelet bases, the acoustic emission signals from stainless steel during the plastic deformation and cracking were analyzed with db5 wavelet and sym5 wavelet. Comparing the results obtained by db5 with that by sym5, it is shown that, during the plastic deformation and cracking of stainless steel specimens with a notch in the tensile test, the tendency of energy distribution is identical, the frequencies corresponding to the main signal peak are identical on the whole, the energy ratios of every scales are obviously different, and the peaks of the signal at corresponding scales are obviously different that the average departure is about 20 percent.

A general method is developed to generate fuzzy control rules by self-organizing and self-learning. This method includes 3 steps: step 1 establishes the experimental system to obtain the data or describing the dynamic characteristics of the system to be considered at real time; step 2 combines the numerical information into a fuzzy rule base to describe the dynamic characteristics of the system, which emulates the operators or domain experts to obtain the linguistic representations of the system; and step 3 uses the dynamic characteristics obtained to design the fuzzy controller by the complex optimization method. The experimental results demonstrate the high performance of the proposed scheme.