Nonuniformity of Isometric Properties of Automotive Driveshafts

This paper presents an analysis of the CVJ (constant velocity joint) of automotive driveshafts from a point of view concerning the nonuniformity of isometric properties. In the automotive industry, driveshafts are considered to have constant velocity through its joints: free tripode joints and fixed ball joints, which has been proved by Mtzner’s indirect method and Orain’s direct method for tripod joint. Based on vectorial mechanics, the paper proved the quasi-isometry of velocity for polypod joints such as fixed ball joints. In the meantime, it was computed that the global nonuniformity of constant velocity joints for modern driveshafts based on the Dudita-Diaconescu homokinetic approach for the driveshafts. The nonuniformity of the velocity isometry of driveshafts was computed as a function of the input angular velocity of the driveshaft, angular inclination between the tripod–tulip axis and the midshaft axis and the angular inclination between the bowl axis and midshaft axis. The main aim of this article is how to improve the geometric and kinematic approach to add an important correction when designing the driveshaft dynamics prediction such as: forced torsional vibrations, forced bending–shearing vibrations, and coupled torsional–bending vibrations for the automotive driveshaft in the regions of specific resonances such as principal parametric resonance, internal resonance, combined resonance, and simultaneous resonances. By the way it is added, there are important corrections for the design of driveshafts, for the torsional dynamic behavior prediction, and for bending–shearing dynamic behavior of the driveshafts in the early stages of design. The results presented in the article represent a starting point for future research on dynamic phenomena in the area mentioned previously.

Stress and Deformation Analysis of Batch Plates using Finite Element Method

The aim of the paper is to check the load-bearing capacity of batch plates. The batch plates are used for coating process of ball joints in a gas nitriding furnace. The plates have circular shape with two types of circular holes, the first type of holes are used for gas flow and the second type of holes are used for ball joints. The plates are laid on the supporting frame. The frame is supported in four suspension eyes, it is loaded by the actual weight of the plate and the plate is loaded by the weight of the stored ball joints. From the results is clear that adjustments need to be made on the supporting frame for the safe operation.

Model development and simulation of vehicle suspension system with magneto-rheological damper

A vehicle suspension system is designed to maintain directional control (road holding) during manoeuvring or braking while supporting the vehicle’s weight and provide stability (handling). The structure of a suspension system consists of parts connecting the axle to wheel assembly and the chassis of an automobile, thus supporting engine, transmission system and vehicle load. Suspension system components consist of dampening devices, springs, steering knuckles, ball joints and spindles or axles. It could be designed according to a passive, semi-active or active mode of working. For evaluation, this assembly could be modelled as a spring-mass-damper system. The semi-active suspension system has been modelled with a magneto-rheological damper following the Bingham plastic theory. In this paper, the performance of a passive and a semi-active suspension of a quarter car model are compared by MATLAB simulation. Thus, a better suspension system is found out by simulating with different road conditions.

No more rattling: biomechanical evaluation of a hexapod ring fixator free of play

Hexapod-ring-fixators have a characteristic rattling sound during load changes due to play in the hexapod struts. This play is perceived as unpleasant by patients and can lead to frame instability. Using slotted-ball-instead of universal-joints for the ring-strut connection could potentially resolve this problem. The purpose of the study was to clarify if the use of slotted-ball-joints reduces play and also fracture gap movement. A hexapod-fixator with slotted-ball-joints and aluminum struts (Ball-Al) was compared to universal-joint-fixators with either aluminum (Uni Al) or steel struts (Uni Steel). Six fixator frames each were loaded in tension, compression, torsion, bending and shear and mechanical performance was analyzed in terms of movement, stiffness and play. The slotted-ball-joint fixator was the only system without measurable axial play (<0.01 mm) compared to Uni-Al (1.2 ± 0.1) mm and Uni-Steel (0.6 ± 0.2) mm (p≤0.001). In both shear directions the Uni-Al had the largest play (p≤0.014). The resulting axial fracture gap movements were similar for the two aluminum frames and up to 25% smaller for the steel frame, mainly due to the highest stiffness found for the Uni-Steel in all loading scenarios (p≤0.036). However, the Uni-Steel construct was also up to 29% (450 g) heavier and had fewer usable mounting holes. In conclusion, the slotted-ball-joints of the Ball-Al fixator reduced play and minimized shear movement in the fracture while maintaining low weight of the construct. The heavier and stiffer Uni-Steel fixator compensates for existing play with a higher overall stiffness.

A Study on Wear and Friction of Passenger Vehicles Control Arm Ball Joints

The following paper describes research on vehicle suspension elements: the ball joints. The worn surface roughness of selected ball pins and their bearings was compared in terms of vehicle mileage, utilization period, and car model. Ball pin roughness was measured using a scanning tunneling microscope (STM), whereas for the bearing surface, a profilometer was used. The aim of this study was to determine the resistive torque in an unloaded ball joint. Using the finite element method, models of the unloaded ball joint were analyzed in two scenarios: with and without interference between the worn ball and its bearing. Calculated values of resistive torques in the ball joint were compared, and recommendations were given relative to the mileage and the time after which it was necessary to perform verification or replacement of the ball joints.

Experimental research on processing incomplete spherical surfaces of machine parts

Improving the durability and reliability of such components as ball joints of cars is very important. The article presents experimental studies to determine surface roughness of incomplete spherical surfaces of machine parts.

Design Improvement of Steering Upright by Investigating Static and Dynamic Analysis

A steering upright is one of the vital components in vehicle dynamics which links all suspension components between the wheel and therefore the vehicle. Upright provides the linkage between the upper & lower ball joints. The upright connects components as an example, control arms, steering arms, suspension springs, shock absorber, brake disc, wheels & tire. Steering upright is a part of mechanical system which contains the wheel hub and assembles to the suspension components. It's the pivot point of the steering and mechanical system, which allows the front wheels to show & more. Agenda of this project is design optimization of steering upright to achieve weight reduction along with required strength and stiffness. Optimized design of upright is necessary with correct material selection further as valid finite element analysis. Optimization is accomplished considering static stress, strain and total deformation analysis with acceptable material selection. Modal and Fourier analysis is to be performed to see natural frequencies and deformation. The experimental testing is going to be performed on UTM. By making the comparative analysis, result and conclusion is drawn.

Device architecture optimization of solder ball joints fatigue lifetime under random vibration frequencies

Purpose This study aims to investigate the vibration effects on ball grid array lifetime. Design/methodology/approach Several finite element method simulations and experiments were performed. Findings An optimized circuit configuration was found. Originality/value The originality of paper is confirmed by authors.