Papers by Keyword: Multi-Body System

Abstract: A novel A/B bi-rotary head is designed which can be used on five-axis machine centers. The motion of pitching and swing can be achieved by controlling the output angle and velocity of motors. Anti-backlash control method can be applied to eliminate the transmission backlash. The error sensitivity model is also established using matrix differential method, and the influence of internal errors on the integrated errors is obtained. The results show that the more sensitive errors can be identified from all errors which need to be controlled rationally.

Abstract: This work deals with the multi-objective dynamic optimization of the suspension system used for the front wheels of a single-seater vehicle. A half-car model is developed, considering the front suspension system mounted, while the rear suspension is replaced with a fictive spherical joint that is placed at the rear axle level. The purpose of the dynamic optimization is to minimize the chassis oscillations (yaw, pitch and roll), the monitored value for each design objective being the root mean square (RMS) during the dynamic simulation. The locations of some important attachments from the suspension system are used as design variables for the dynamic optimization. The dynamic model is analyzed in the passing over bumps regime, the wheels being anchored on driving actuators, whose motion simulate the road profile. Specific modules of the MBS (Multi-Body Systems) software environment MSC.ADAMS are used in this study.

Abstract: Nonlinear equivalent spring resistance model and Coulomb friction model is used to construct a dynamic mathematical model for a multi-body system, which contains clearance. In the paper an internal combustion engine dynamic model has created for simulated analysis. It shows that joints accuracy and driver speed have obvious effects on crank slider dynamic disturbance. Also joints clearance and the increase of driver speed lead to lower positional accuracy, worse stability and reliability, which has very important theoretical significance and practical value on the analysis of the performance of internal combustion engine.

Abstract: In this paper, we attempt to carry out the dynamic analysis of a motor vehicle, using the virtual prototype developed with the MBS (Multi-Body Systems) software ADAMS. The virtual prototype includes the front and the rear suspension subsystems, the steering subsystem, and the car body subsystem. The experiment designed is one frequently carried by the automotive manufacturers, namely passing over bumps. The connection between wheels (tires) and road (ground) is made using contact forces, which allow modelling how adjacent bodies interact with one another when they collide during the simulation. On the virtual prototype, several measurements have been realized having in view to evaluate the dynamic behaviour of the vehicle.

Abstract: Finite element model of track in frog zone is built by vehicle-turnout system dynamics. Considering variation of rail section and elastic support, bending deformation of turnout sleeper, spacer block and sharing pad effects, the track integral rigidity distribution in longitudinal direction is calculated in the model. Vehicle-turnout rigid-flexible coupling model is built by finite element method (FEM), multi-body system (MBS) dynamics and Hertz contact theory. With the regularity solution that different stiffness is applied for rubber pad under sharing pad of different turnout sleeper zone, analysis the variation of vertical acceleration of bogie and wheelset, rail vertical displacement and wheel-rail interaction force, this paper proves that setting reasonable rubber pad stiffness is an efficient method to solve rigidity irregularity problem.

Abstract: Against to the problem of widely used of software error compensation, raises error compensation device to instead of PC to realize erro r compensation. And introduces multi-body system relating to error compensation, represents the feasibility and implementation techniques of software error compensation using SCM. This program will show great values in the field of CNC.

Abstract: Heavy duty machine tool has some special points, such as large size, complex structure, long cycle at Installation and commissioning, high requirements assembly processes and so on. Therefore, this paper established a mathematical model to transform the origin parts of the gantry machining center into assembly special form and creates a software as a plug-in for Solidworks based on it, proposes an easy but very practical assembly method based on Multi-body system under virtual environment. This method can calculate assembly deviation caused by manufacturing tolerance very quickly, and bring the sensitivity information clearly. Assembly deviation sensitivity and assembly method proposed in this paper can provide a way for the virtual assembly of heavy-duty CNC machine tools, Thus provide an important theoretical basis to improve the performance of the machine

Abstract: The design for a double-axis double-rest CNC machining center is introduced by describing its key machine elements and machine tool design procedures. Then based on the theory of the multi-body system, the modeling process of the volumetric error model for the CNC machining center is expatiated and the result of the modeling is given. It is verified that the error of the machine tool is from three line error and three angular errors between structural units as well as the vertical error between axes. Finally experiments are carried out to evaluate the machining performance of this designed machine tool.

Abstract: Aiming at globoidal cam one-side machining errors in addition to programming error, there exists combined effects of a number of the original errors, such as, machine motion error, tool error, fixture error and et al. On basis of the analysis of the principle of one-side processing, the theoretical calculation synthetic model of the one-side machining profile normal error is established based on the multi-body system error modeling theory and spatial mechanism conjugate meshing principle. And by applying Newtons iterative method and simulations in Matlab, the law of comprehensive influence of each original error on globoidal cam profile normal error is revealed. The simulation results verify the correctness of the theoretical calculation error synthetic model, and a scientific proof is provided for further improving machining accuracy of one-side machining of globoidal cam.

Abstract: This paper approaches the multi-criteria kinematic optimization of a front multi-link suspension mechanism. The optimization purpose is to minimize the variations of the wheel track, wheelbase, castor angle, and induced deflection angle, the monitored values being the root mean squares during simulation. The locations of the joints by which the guiding links/arms are connected to the adjacent parts are used as independent variables in the optimization process. The investigation strategy is based on a design of experiments technique - DOE Screening, obtaining the appropriate regression model. The goodness-of-fit has been verified by computing the variance in the predicted results versus the real data, the probability that the fitted model has no useful terms, and the significance of the regression. The study is performed by using the multi-body system environment ADAMS of MSC Software.