Papers by Author: Guang Meng

Abstract: In this paper, influencing factors and evaluation standards of vibration on human comfort were summarized. The mainly influencing factors were analyzed including vibration acceleration, frequency, exposure time and other factors. The evaluation standards of human comfort were analyzed contrastively. The conclusion was that countries around the world have established unified body vibration comfort evaluation methods and evaluation standards on the basis of ISO series standards. The new methods and standards were also needed for special vibration and shock environment.

Abstract: The quasi-zero-stiffness vibration isolation system has witnessed significant development due to the pressing demands for low frequency and ultra-low frequency vibration isolation. In this study, the isolation theory and the characteristic of the quasi-zero-stiffness vibration isolation system are illustrated. Based on its implementation mechanics, a comprehensive assessment of recent advances of the quasi-zero-stiffness vibration isolation system is presented. The future research directions are finally prospected.

Abstract: Large-scale air separation equipment is used widely in chemical industry. It can provide oxygen, nitrogen and argon for the production process. Based on the deep analysis of the working principle and using equipment, the air separation unit product data management (PDM) system is developed by Visual Basic (VB) in this paper develops. The modularized design procedure and grouping technique (GT) are adopted in this system. The morphological matrix is used to establish their coordination relationship among parts. The system has many characters, such as perfect function, reasonable database structure, and concise software interface layout. Optimizing equipment parts management properly and effectively has important practical significance in designing the subsequent product development work and establishing concurrent design environment of the air separation unit.

Abstract: A novel drive joint based on the principle of interaction between electromagnet and permanent magnet is introduced, which may be used in active vibration control. The toque model and the dynamic model of the system are built. The toque model is verified by the results of Finite Element Analysis (FEA). Finally, the dynamic simulation based on the model is carried out.

Abstract: This paper presents a research work for the design and modeling of a new inchworm linear motor. The three actuators of the motor are based on electromagnetic and permanent magnetic combined drive. The actuator may generate large output force, large displacement and quick response. A permanent magnet cam is designed to realize the continuous and smooth movement for the actuator. The motion equation of the cam mechanism is established and analyzed by SIMULINK from which the optimal contour of the cam may be confirmed. Then the general dynamic model of the linear motor is established with a 4DOF lumped parameter system.

Abstract: Giant magnetostrictive actuator (GMA) has advantages over other actuator made of intelligent materials in aspects like quick response, large output force, and high precision. But the lack of displacement, relatively big size and heavy weight block its popularization. In this paper, a new mini linear motor based on three GMAs is designed. It is the second generation motor derived from the improvement of the first generation linear motor that is realized in our previous work. To compensate the structural defects and to improve the traveling performance of the previous one, we redesign the motor in the structure, especially the frame as a whole by considering not only the basic supporting and connecting role but also the displacement amplifying function in it. The paper presents the process of the structural design of the mini linear motor, the establishment of the motor’s system dynamic model and the traveling simulation under SIMULINK. The new structural scheme and the motor’s system modeling approach are validated by the simulation results. Keywords: magnetostrictive; inchworm linear motor; structural design; dynamic modeling

Abstract: A new kind of 3-d.o.f. vibration platform is introduced, which may be used in active vibration control, presion manufacturing, and other precision positioning fields. The platform is mainly comprised of four parts: the top board of the platform, flexure hinges, amplification mechanisms and gaint magnetostrictive actuators (GMAs). Among them, finite element analysis is taken on flexure hinges; the constitutive model of GMA is described. Eventually, the dynamic model of the system is established. According to the model, a simulation system based on SIMULINK is carried out. The simulation results verify the model, and may serve for the active control analysis of the platform system.

Abstract: Finite element (FE) method is an efficient and power tool, and is adopted to analyze dynamic response of printed circuit board (PCB) assembly. First, FE model of PCB assembly was established. Second, the dynamic behaviors of ball gird array (BGA) lead-free solder joint were obtained when the PCB assembly was subjected to a half-sine acceleration pulse. Results show that the maximum tensile stresses occur at solder joints located at the four outermost corners of BGA and solder joints at outermost corners are the most vulnerable to crack. In addition, it can be found during FE analysis that the solder joint reliability can be enhanced as the PCB damping increases and input acceleration level reduces.

Abstract: This paper analyzed an approximate treatment of the nonlinear dynamical system of an electrostatically actuated micro-cantilever subjected to combined parametric and forcing excitations in MEMS. In this approximation, the nonlinearity is expanded into Taylor series. By retaining a number of terms, a modified system is obtained and then employed to study the real system indirectly. Bifurcations and sub-harmonic responses of the real system and of the modified system are obtained via numerical integrating methods. It was found, modified systems with only several terms cannot simulate multi-periodic and quasi-periodic responses of the real system. However, as long as enough terms are taken into account, the modified systems can give rise up the real responses no matter how complex they are.

Abstract: A piezoelectric active sensor network is configured to collect the wave scattering from a throughthickness hole on an aluminium rectangular tube. It is found that guided waves are capable of propagating across the tube edges, while keeping the sensitivity to the damage even not on surfaces where the actuator and sensor are located. Signal correlation between the intact and damaged structure is evaluated and the probability distribution of damage is thus achieved on the unfolded tube surface.