Applied Mechanics and Materials Vol. 470

Abstract: The effect of the mechanical properties and geometric parameters on the crack density of the thin film/substrate system under residual stress and uniaxial tensile loading is investigated in this work. The numerical results show that the crack density of the thin film increases with the increase of the Youngs modulus of the thin film and (or) the shear modules of the interface layer, and it decreases with the increase of the thickness of the thin film and (or) the fracture strength of the thin film. These results can help us more deeply understand the fracture behavior of the brittle thin film on the substrate under residual stress and external tensile loading.

Abstract: From various previousexperimental researches, the stable hysteresis of brake liningpads-to-stainless steel sheet friction interfaces has been verified.However, most of previous researches concentrated on the linear frictionbehavior of the brake lining pads-to-stainless steel sheet interfaces andresearches on rotational friction behavior are very limited. Therefore, thisstudy experimentally investigates the rotational friction behavior of theinterfaces and the influence of normal pressure applied by torque ofhigh-strength bolts. Cyclic loading tests were carried out with changing normalpressures.

Abstract: monorail spatially coupled dynamic modeling which has three directions attached contacts wheel have been established. According to the simulation and experimental results, dynamic model was validated. based on the dynamic coupling modeling , the tire parameter influence trends for the tire wear of walking wheel’s tires were analyzed when monorail vehicle curve driving. The analysis result revealed that because the contact of straddle-beam monorail is special, with the cornering stiffness increases of walking wheel tire, by the impact of the contact radial force from guide wheels and stabilizing wheels, the lateral forces of walking wheel is gradually increasing. tire wear speed increases at a constant when monorail vehicle curve driving.

Abstract: Inertia parameters are essential for motor assembly mounting design, which mainly includes the mass, center of mass (CM) coordinates, moment of inertia and product of inertia. This paper explains the principle and methods of modal test method. One vehicle drive motor assembly is taken as the research object, its inertia parameters are identified using this modal test method. Finally test error analysis is also performed.

Abstract: The kinematic and dynamic performances of piston-connecting rod mechanism of internal combustion engine (ICE) were analyzed in detail. Taking standard slider-crank mechanism as study object, the kinematic and dynamic parameters (velocity, acceleration, angular acceleration etc.) of linkage were derived. Under no any simplification, the calculating method of each physical parameter was provided. Meanwhile, taking the factual force applied to connecting rod into account, the graphical method of vector equation was used to solve each load imposed on connecting rod. The research works were believed to be beneficial to subsequent finite element analysis (stress and train fields, fatigue of connecting rod) and size optimization design of connecting rod.

Abstract: As for squat trainer, acommon fitness equipment, we do mechanical analysis and structural optimization from manufacturing costs and safety. With physical structure analysis and intensity check, we have materials and structural optimization for the equipment. This analysis method can be extended to other fitness equipment.

Abstract: Welded tubular joints are widely used in long-span, space and offshore structures. In a welded tubular joint, the chord is generally subjected to loads in radius direction which are transmitted from the brace members in axial direction. As the strength of the chord in radius direction is generally much weaker than that of the brace in axial direction, failure occurs easily at the weld toe on the chord surface. To improve the bearing capacity of the joint structure, reinforcement is necessary. Several reinforcing methods were reported in the literature, such as doubler or collar plate reinforcement, internal stiffened ring reinforcement and bracket reinforcement etc. This paper presents the strengthening method by inner plate. From finite element analysis of many inner plated reinforced tubular joint models, the efficiency of reinforcement by inner plate is analyzed by comparing the static strength of reinforced models with that of unreinforced models. Based on a parametric study of the static strength of tubular joints reinforced by inner plate, the design considerations on inner plate strengthening tubular joints are also proposed.

Abstract: Aiming at the key problem in determining the modal parameters of bearings finite element model (FEM), an equivalent model to investigate the bearings dynamic parameters was proposed based on the Sjoväs load integral formulae, and several unequal units of spring and damper were applied; an experimental device for testing the bearings dynamic parameters was developed. The comparison of experimental results and simulation results showed that the proposed modeling approach could accurately analyze the modal parameters of bearings, and the relative errors of corresponding vibration frequencies in the radial and the axial directions could be controlled within 3%.

Abstract: According to the character of the torque and speed ripple of the engine idling analysed from its Fourier transformed, use motor torque to compensates the primary and second harmonics of Fourier transform of the output net torque during engine idle in HEV. The simulation results show that the engine torque ripple and speed ripple decrease greatly, so the system smoothness and economic efficiency were achieved.

Abstract: The curve through performance of straddle type monorail vehicle include performance-oriented, preventing derailment stability, preventing vehicle overturning stability, tire wear performance, which are evaluated by oriented torque, the minimum vertical force of horizontal wheels, vehicle body roll angle, overturning coefficient, the sum of tire forces scalar. With the virtual simulation model in ADAMS, this paper analyzes the impact of the monorail vehicle suspension stiffness parameters on the evaluation indexes by sensitivity analysis.