Advanced Materials Research Vols. 1006-1007

Abstract: This study based on the finite element method, the type of XB1-120-100 harmonic drive output torque and input rotational speed impact on transmission efficiency has been analyzed. The results show that the efficiency of harmonic gear drive increases with the output torque increased, and it has no relation with input rotational speed. When the output shaft takes the value of rated torque (T_out=450Nm), the transmission efficiency of harmonic gear drive obtained by the finite element numerical simulation is 87.1%. This value of transmission efficiency is quite close to the type of XB1-120-100 harmonic drive efficiency (75%-90%). The above analysis method and results have a guiding significance for the transmission design and performance analysis of harmonic gear drive.

Abstract: Automated Mechanical Transmission (AMT) is applied as a new starting device for belt conveyor in the paper. Simulation model of AMT driving belt conveyor is established in AMESim. Simulations of start-up process at first gear condition and shifting process from first to eighth gear are discussed. Belt velocity is accepted as the law of gearshifts to judge the moment of shifting. Simulation results show that AMT could achieve the purpose of belt conveyor’s soft-starting gradually. The belt appears short-time acceleration mutations during shifting process which results in the belt maximum tension, the driving pulley torque, and other parameters changing within their allowable limits. The belt maximum tension appears short-time mutations when the clutch is just engaged, in which case the peak value of belt maximum tension can achieve 110 KN approximately, and is less than its allowable limit. After shift actions, the belt maximum tension and other parameters curves tend to be stable.

Abstract: Abstract: Automotive vibration characteristic analysis is of great significance, the vibration influence of ride comfort, the working efficiency and good health.Therefore, measures should be taken to reduce the vibration of the vehicle and keep the working environment of comfort, to ensure the driving personnel under the condition of the motion of the complex and manipulated with good psychological state and accurate sensitive reaction.

Abstract: In order to obtain actual dynamics equation of 3-PPR planar parallel mechanism, established mechanical model of kinematic pair including friction, carried on force analysis of 3-PPR planar parallel mechanism including friction. Then according to the Kane equation established the dynamics equation of 3-PPR planar parallel mechanism including friction.

Abstract: Many researchers applied creepage to calculating creep force, and relation between creepage and creep force are very complex and it has been a major problem for solving rolling contact theory. The paper established the finite element model of wheel-rail rolling contact based on ALE method (Arbitrary Lagrange-Euler method) in ABAQUS, and research impact of lateral motion of wheelset on creepage of wheel-rail contact. Results show in the lateral movement value difference between their longitudinal creepage is small, and maximum error is less than 20%, there is more distinct change trend about lateral creepage in left contact area than one in right contact area, and spin creepage of left wheel drop down in 4mm lateral displacement.

Abstract: The bullet-rifle coupling model of sniper rifle has established to study the impact of bullet mass eccentricity on initial disturbance. This coupling model was established based on nonlinear finite element method and used to simulate the launch process of sniper rifle under the condition of gravity static equilibrium in the method of the mixing calculation which had advantages of both dynamic explicit algorithm and static implicit algorithm. The impact of different initial position of mass center on bullet swing angular displacement and centroid displacement was considered. Numerical calculation results shows that bullet mass eccentricity has a great influence on initial disturbance, the bullet swing angular displacement and centroid displacement is closely related to initial position of mass center. In addition, there is proportionality between bullet swing angular displacement and axial velocity before it reaches limit. That is helpful to carry out further study of how to control the influence of mass eccentricity on initial disturbance.

Abstract: Comprehensively taking the effects of variable rigidities, tooth flank clearances, bearing clearances, contact rigidities, and other multiple non-linear factors into account, it built a bend and torsion coupled gear-driven system’s dynamics analysis model in use of lumped mass method. After dimensionless dealing, it solved this dynamic model by the method of fifth order adaptive variable step (Runge-Kutta) method, and then it obtained system vibratory responses’ time domain diagrams, frequency domain diagrams, phase map, Poincare diagram, fast Fourier transformation (FFT) diagrams, and system branch diagrams under different parameters. All of them analyzed the effects of parameter variations on gearing system’s dynamic characteristics, and it provided a foundation for gearing system dynamic optimum designs.

Abstract: Based on the study of a dual component system with elastic constraints, the stability and local bifurcations of the soft-impacts system, such as piecewise property and singularity, was analyzed by using the Poincaré map and Runge-Kutta numerical simulation method. The routes from periodic motions to chaos, via Hopf bifurcation and period-doubling bifurcation, were investigated exactly. In the large constraint stiffness case, the period-doubling and Hopf bifurcation exist in the two-degree-of-freedom system with elastic constraints and clearances. The clearances of the system, stiffness and damping coefficient of the elastic constraints is the main reasons for influencing the chaotic motion. The steady 1-1-1 period orbits or 2-1-1 period orbits will exist within a wideband frequency range and the value of velocity will be higher when appropriate system parameters are chosen.

Abstract: A virtual prototype model of lock-pin synchronizer is built by using CATIA and ADAMS. The kinematics and dynamics simulation and analysis of synchronizer are carried out. The effect law between change of characteristic parameters, such as engine speed, cone radius, the input end of moment of inertia, friction coefficient of lock surface, and synchronization time are obtained. The reference for optimizing performance of synchronizer is provided by the simulation results.

Abstract: In this paper, a multi-body dynamics model of amphibious vehicle is established in terms of dynamic simulative software ADAMS/Car. The front and rear suspension system are studied and analyzed respectively. The handling stability performance of front suspension is simulated under step steering input, pulse steering input, steady turning, and meandered test in related to specifications. According to the simulation results, the handling stability of amphibious vehicle is evaluated objectively.