Browse Topic: Fasteners

Items (5,105)
Engine is the prime mover of an automobile. Tractor is also equipped with engine of higher capacity to meet the power requirement. Apart from powering the wheels, engine also runs different accessories such as water pump, alternator, AC pump, Oil pump and so on. The power from the engine is transferred to accessories via chain drive or belt drive through the crankshaft pulley. During field testing, in one of the tractors, engine pulley mounting bolt failure was reported. The failure resulted in immediate seizure of the engine making the tractor standstill in the field. The root cause of the failure was unknown. Hence, there was a need to develop a component or subsystem level test methodology to address the issue quickly. In the current scope, an attempt was made to develop a subsystem level laboratory test methodology to simulate the failure mode and to validate the design modifications in an accelerated manner. The failure mode was simulated in lab and different design iterations
Chakraborty, Abhirup
The smart industrial revolution in any organization brings faster product delivery to the market, which can meet customer expectations and full life requirements without failure. Failure per machine (FPM) is a very critical metric for any organization considering warranty cost and customer perception. One such area which needs a detailed evaluation is bolted joints. Bolts play a pivotal role when integrating a subassembly with the main structure. Often, it is challenging to address bolt failure issues due to vibration induced in structures. Current bolt virtual evaluation methods help to evaluate bolts in simple loading conditions such as axial and bending loads. But it is quite complicated to evaluate the bolts which are prone to vibration loading. Traditional methods of using gravity loads miss out on dynamic characteristics, hence it must be simulated using modal dynamic analysis. With the current vADV (virtual accelerated design verification) method it is not possible to capture
Desale, Amit NanajiSingh, GurwinderVhatkar, RushikeshPatil, Akhil
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
When the lighting is uneven, the local direction of the light strip in the railway track fastener image output by column traversal will be affected by the curvature value of the light strip, resulting in discontinuity and inability to effectively obtain the loose state of the fastener. Therefore, a real-time automatic detection algorithm for railway track fastener looseness under uneven lighting conditions is proposed. After Gaussian filtering denoising, the neighborhood of the image center point is described using an eight neighborhood chain code. Insert coarse positioning points between the centers of intermittent light strips based on neighborhood grayscale. Determine the direction of the local light band by traversing the output vertically, horizontally, diagonally 45 ° to the left, and diagonally 45 ° to the right. After aggregating the local direction of the light strip to obtain complete contour information, calculate the gap between the clip and the elastic strip, and use it as
Li, YuepengHu, Fanglei
Self-piercing riveting (SPR) is a key joining method in multi/thin-material automotive structures, yet accurately predicting the mechanical strength of SPR joints remains challenging due to numerous influencing factors. Empirical engineering equations [1] provide a foundation for estimating lap-shear and cross-tension strength but require several geometric parameters that are often unavailable in the design phase. To address this limitation, we extract and leverage the core physical relationships embedded in these formulas. By reformulating the dependence of joint strength on the yield strength and total thickness of the sheet stack as practical regression models, we enable strength prediction using only commonly available material properties. Furthermore, a Bayesian convolutional neural network (BCNN) model is developed to incorporate additional material features, offering improved prediction accuracy and uncertainty quantification.
Soproni, IstvanWomack, DarrenLiu, ZongyueBalaji, AshwinKulange, Deepak
Plastic materials are used for a wide variety of spacecraft applications including seals, bearings, fasteners, electrical insulators, thermal isolators, and radomes. Selecting plastics for use in space is complex due to wide operating temperature ranges, vacuum conditions, and exposure to radiation and atomic oxygen. Additionally, some spacecraft applications require sealing flammable propellants such as hydrogen and oxygen. This article will present some design considerations when selecting plastics for use in spacecraft. It will provide rich data on the performance characteristics of plastics as well as examples of successful spacecraft applications.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Electric vehicles (EVs) require improved drag performance from wheel bearings to achieve a longer range. EVs are heavier and have higher torque output compared to internal combustion-powered vehicles. Due to the increased weight and torque of EVs, there will be higher loads at the bearing-to-knuckle joint. These increased loads may necessitate higher clamp loads to maintain joint integrity. However, higher clamp loads can lead to distortion or reduced roundness of the wheel bearing outer ring. Such distortion permanently increases drag and reduces bearing life. Therefore, after vehicle corner assembly with higher clamp loads, it is critical to minimize outer ring distortion during the initial assembly and throughout the bearing's lifespan. This paper will cover the design considerations for the wheel bearing outer ring to minimize distortion, utilizing Computer-Aided Engineering (CAE) analysis for various designs. A Design of Experiments (DOE) will be conducted to understand the
Mandhadi, Chaitanya ReddyCallaghan, KevinSutherlin, RobertLee, SeungpyoLee, YeonsikBovee, Benjamin
This SAE Recommended Practice defines a clearance line for establishing dimensional compatibility between drum brakes and wheels with 19.5-inch, 22.5-inch, and 24.5-inch diameter rims. Wheels designed for use with drum brakes may not be suitable for disc brake applications. The lines provided establish the maximum envelope for brakes, including all clearances, and minimum envelope for complete wheels to allow for interchangeability. This document addresses the dimensional characteristics only and makes no reference to the performance, operational dynamic deflections, or heat dissipation of the system. Valve clearances have not been included in the fitment lines. Bent valves may be required to clear brake drums. Disc brake applications may require additional running clearances beyond those provided by the minimum contour lines. Mounting systems as noted are referenced in SAE J694.
Truck and Bus Wheel Committee
This SAE Information Report is provided as an advisory guide and is not intended to be made a procurement requirement. Individual application discretion is recommended. The content has been presented as accurately as possible, but responsibility for its application lies with the user. The document covers a number of the variables in the torque-tension relationship: friction, materials, temperature, humidity, fastener and mating part finishes, surfaces, and the kind of tightening tools or equipment used. With an understanding of the variables to be considered, several methods to determine and tighten fasteners using the torque-tension relationship are identified. This guide is limited in application to fasteners with ISO-metric or UN series threads. Other thread types, such as self-tapping or thread forming, may apply to some aspects of this standard but are not specifically covered. The procedures described in this document are based on general factors for the determination of the
Fasteners Committee
E-25 General Standards for Aerospace and Propulsion Systems
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This paper presents an analytical approach for identifying suspension kingpin alignment parameters based on screw axis theorem and differential calculation model. The suspension kingpin caster and inclination alignment parameters can produce additional tire force, which affects vehicle handling dynamics. In wheel steering process, the multi-link suspension control arms lead to movement of the imaginary kingpin, which can cause change in suspension kingpin alignment parameters. According to the structure mechanism of commercial vehicle multi-link independent suspension, the kinematics characteristics of imaginary kingpin were analyzed based on the screw axis theorem. The angular velocity and translation velocity vectors were calculated. In order to avoid the influence of bushing deformation, the unique differential identification model was established to evaluate the suspension kingpin alignment parameters, and the identification results were compared with the ADAMS/Car data. The
Ding, JinquanHou, JunjianZhao, DengfengGuo, Yaohua
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB
Xu, ChuanyanWang, JianjunXing, QisenChen, HengbinHuang, Xianli
This paper investigates the performance of a dissipative material compared to conventional acoustic materials under conditions that simulate real-world vehicle applications with acoustic leakage. Various acoustic materials were evaluated through laboratory experiments, which included acoustic leakage in both the steel panel and the acoustic materials. Acoustic leakages commonly occur in actual vehicle conditions at pass-throughs or fastener mounting locations. The study also presents in-vehicle test results to demonstrate the effectiveness of the dissipative material in managing acoustic leakage.
Yoo, TaewookMaeda, HirotsuguSawamoto, KeisukeAnderson, BrianGan, KimTongHerdtle, Thomas
This paper reports on a new design of semi-automatic riveting machine designed to be affordable. This work started in 2024. There are no customers yet. The machine is all electric. The machine installs interference bolts as well as squeeze rivets. Cost is a key criterion. The machine must feed a wide variety of fasteners. This machine is called Flexriveter.
Zieve, PeterReznicek, Jeffrey
Biomedical metal implant materials are widely used in clinical applications, including dental implants, hip replacement, bone plates, and screws. However, traditional manufacturing processes face limitations in meeting customized medical needs, internal structural control, and efficient material utilization. For example, when producing complex-shaped titanium alloy parts using conventional methods, the material consumption ratio is as high as 10:1–20:1, leading to significant material waste.
This SAE Aerospace Recommended Practice (ARP) provides the recommended procedure for obtaining desired preloads in aircraft wheel tie bolts when mounting tires and assembling the wheel. It is generally referred to as the snug-angle bolted joint assembly procedure. It is also known as the “torque-turn” procedure in the heavy equipment ground vehicle industry.
A-5A Wheels, Brakes and Skid Controls Committee
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
At present, electric head restraints have been developed locally, so overseas mechanisms are used. In this study, two concept mechanisms were developed, and in addition, one patent for a wing-out head restraint mechanism was additionally applied. The new mechanism has had an excellent effect on cost reduction and improvement of operating noise compared to the current one.
Yu, Sanguk
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
This specification establishes the requirements for the following types of self-locking nuts in thread diameter sizes 0.1380 through 0.6250 inch: a Wrenching Nuts: i.e., hexagon, double hexagon, and spline nuts. b Anchor Nuts: i.e., plate nuts, gang channel nuts, and shank nuts. The wrenching nuts, shank nuts, and nut elements of plate and gang channel nuts are made of a corrosion- and heat-resistant nickel-base alloy of the type identified under the Unified Numbering System as UNS N07001 and of 180000 psi axial tensile strength at room temperature, with maximum conditioning of parts at 1400 °F prior to room temperature testing.
E-25 General Standards for Aerospace and Propulsion Systems
In commercial vehicle, Hydraulic Power Assisted Steering (HPAS) gear plays a vital role to utilize the hydraulic force to assist the steering application. HPAS gear consists of housing, sector shaft, side cover, worm shaft, valve housing and rack piston. Side cover assembly is connected with the housing assembly through bolts which is in exposure to high pressure working hydraulic fluid. Since, some of the bolts are exposed to the fluid environment in the inner surface of the housing, during high pressure running condition, torque relaxation in the bolt is observed which leads to the loosening of bolts and tends to hydraulic fluid leakage through bolts. The current phosphate coated bolts are getting relaxed and loosened due to the bolts that exposed to the oil environment which have insufficient coefficient of friction in the bolt head and thread. To overcome the bolt failure during high pressure hydraulic application, various bolt coating analysis is experimented to withstand the
Ayyappan, RakshnaGovindarasu, AnbarasuP, RajasekarD, Senthil Kumar
The study of residual torque is necessary in various fields to ensure the safety and reliability of bolted joints. The present study aims to determine, experimentally, the decrease in torque applied to a nut used in the assembly of two polymeric components (POM - Polyoxymethylene). These components are part of the fuel supply module, responsible for supplying fuel from the tank to the engine. This reduction in torque initially applied is mapped to the end-of-life of the components and is used as an approval criteria in the audit procedures of the Robert Bosch company. The first component features an overmolded metallic screw, injected into POM. The mating part is also injection molded from POM and is assembled onto the first part, secured by tightening a metal nut. Due to the plastic-to-metal interface, it’s expected that there will be a reduction in the initially applied torque required to fasten the pieces together. The study was based on 5 steps: 1 Theoretical study on residual
Spitaletti, Laís Scotelarida Fonseca, Márcio Ghiraldelli
This specification covers metric aircraft quality spacers for use as positioners for tubes, flat washers for use as load spreaders, galling protection of adjacent surfaces and or material compatibility, and key or tab washers for use as locks for bolts, nuts, and screws.
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
E-25 General Standards for Aerospace and Propulsion Systems
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