Applied Mechanics and Materials Vols. 300-301

Abstract: A vibration model is proposed and analyzed dynamically to study the self-synchronization theory of dual-mass vibration system. The differential equations of systematic motion are derived by applying Lagrange’s equations. Two uncertain parameters 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.

Abstract: Advanced thermal management system (TMS) has the potential to increase the life of the vehicle’s propulsion, and meanwhile, decrease fuel consumption and pollutant emission. In this paper, an advanced TMS which is suitable for a series-parallel hybrid electric vehicle (SPHEV) is presented. Then a numerical TMS model which can predict the thermal responses of all TMS components and the temperatures of the engine and electric components is developed. By using this model, the thermal response of the TMS over a realistic driving cycle is simulated. The simulation result shows that the TMS can fulfill the heat dissipation requirement of the whole vehicle under different driving conditions. It also demonstrates that a numerical model of TMS for SPHEV is an effective tool to assess design concepts and architectures of the vehicle system during the early stage of system development.

Abstract: In order to investigate the magnetic signals on the surface of the ferromagnetic component, which have suffered the tensile fatigue under weak static magnetic excitation, an experiment is set up to operate the research. The 16MnR is adopted to make the specimen which will get the tensile fatigue, with a prefabricated small crack in the center position of it. The probe based on the GMR Array is engaged in the signal acquisition system. Magnetic signals at different tensile stage is obtained and mapped, as well as its gradient. Research between the characteristics of the signals and the specimen’s suspicious stress concentration or damaged area has been discussed to make a proper evaluation to the components.

Abstract: In this paper, a forging problem is analyzed by using the overrange collocation method (ORCM), which is a new meshless method. By introducing some collocation points, which are located out of domain of the analyzed body, unsatisfactory issue of the positivity conditions of boundary points in collocation methods can be avoided. Because the overrange points are used only in interpolating calculation, no overconstrain occurs in partial differential equations on the solved problems.

Abstract: In order to analyze the effect of foundation pit excavation on surrounding buildings, this paper researched the ground surface deformation surrounding excavation engineering, analyzed the buildings additional internal forces change mechanism and the coordination of the building foundation and the ground; The damage were researched on foundation subsidence, ground tilt, surface curvature, torsion and other factors on surrounding buildings and affiliated facilities after excavation. Established an interaction theory model of the buildings foundation and ground, used the model could calculate the changes of internal force and deformation of surrounding buildings caused by foundation pit excavation by selecting the reasonable foundation settlement equation or using the measured settlement data. So this paper provided a theoretical calculation method to engineers to calculate the effect of excavation engineering on surrounding buildings.

Abstract: In the paper the shear wave velocity profile is studied using the MASW test. The experimental dispersion curves were obtained from the signal process proposed by Ryden. Theoretical dispersion curve can be constructed by thin layer stiffness matrix method. A real-parameter genetic algorithm is required to minimize the error between the theoretical and experimental dispersion curves. To reduce the error of experimental and theoretical dispersion curve using real-parameter genetic algorithm is feasible. The results show that the soil layers of the study area can be modeled as a sandy fill overlaid on an underlying half space. Test results also show that the asymptotes at high frequencies of the fundamental mode approach the phase velocities for the fill of 190 m/s. The depths of weathered bedrock estimating from dispersion curves match well with that of borehole data.

Abstract: On rough road busy-shifting often occurs when shifting law is built based on traditional two parameters (i.e., velocity and throttle). In order to resolve this problem, this paper provides a method of recognizing rough road and modifying shift point. At first, a dynamic model was set up to demonstrate the possibility of identifying rough road by longitudinal acceleration. Furthermore, advantages of the engine speed variation rate were analyzed, so engine speed variation rate distinguishing the rough road was proved better. Then the analysis of time-domain and frequency-domain of the engine speed variation rate was carried out .On the basis of the result, the method of frequency domain based on the FFT and “Cross Meter Method” based on the times of the instantaneous values of engine speed variation rate greater than the threshold value was proposed. At last, the method of modifying shift strategy was proposed on the rough road. Through the road test, it was effective to prevent busy-shifting on rough road.

Abstract: Combining with rotational speed measurement methods and underwater environment particularity, an independent velocity measurement scheme applicable to small underwater high-speed moving body was proposed in this paper. The structural design of the measurement device was designed and signal process method was improved, and the relationship between turbine rotational speed and speed of the body was obtained by FLUNET dynamics simulation and water tunnel experiments. Finally, the simulation and experimental results were analyzed. The results show that this method is effective and feasible within a certain range of accuracy.

Abstract: A finite beam element model of the spindle which is one of key parts of the high-speed winder is presented in this paper. Critical speeds of the spindle based on the finite beam element model are obtained considering the effect of rotatory inertia, gyroscopic moments, and the damping. Harmonic response analysis of the high-speed winder spindle is developed in two conditions including static unbalance and couple unbalance. The dynamic analysis mentioned above is implemented by using the finite element software ANSYS. Calculation results in this paper are helpful for the dynamic balance of the high-speed winder spindle.

Abstract: A translational-rotational-coupling dynamic model has been built in the carrier-attached coordinate system.Differential equations of the system have been derived, and the natural frequencies and vibration modes of the planetary gear set have been obtained through solution of the associated eigenvalue problem. Based on the properties of the transmission system, the vibration modes of 2K-H spur planetary gear set can be classified into three categories, i.e., translational mode along radial direction, rotational mode, and planet mode.