This recommended practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include axle spindle, bearing cones, bearing spacer, seal and wheel hub. This recommended practice is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, FL, I80, L, N, P, R, U, and W.
This SAE Aerospace Information Report (AIR) describes the design approaches used for current applications of aircraft Brake-by-Wire (BBW) control systems. The document also discusses the experience gained during service, and covers system, ergonomic, hardware, and development aspects. The document includes the lessons that have been learned during application of the technology. Although there are a variety of approaches that have been used in the design of BBW systems, the main focus of this document is on the current state of the art systems.
ZF Friedrichshafen AG has formed a joint venture with YTO, a leading manufacturer of construction and agricultural machines, on the production of tractor steering axles for vehicles from 25 to 230 hp (19 to 172 kW).
WABCO recently opened a new Application Engineering Center in Pune, the supplier’s second such facility in India. The new center will allow WABCO’s team of application and test engineers to work closely with global commercial vehicle (CV) manufacturers in India to jointly develop customized products and solutions across a broad range of vehicle platforms, the company said in a release.
Troy, MI-based Meritor, Inc. and brake system supplier Brakes India, Ltd. have signed a licensing and technology assistance agreement for the manufacture and sale of Meritor ELSA air disc brakes in India.
No scope available.
This specification covers minimum design and test requirements for aircraft tire inflation-deflation equipment for use on all types of aircraft. It shall be the responsibility of the airframe manufacturer to determine the compatibility of the requirement with the applicable aircraft and to specify requirements in excess of these minimums as necessary.
The purpose of this SAE Standard is to offer simplified and prioritized guidelines for collecting and preserving on-scene data related to motor vehicle accidents. It is intended that these guidelines improve the effectiveness of data collection, which will assist subsequent analysis and reconstruction of a particular incident. The document is to guide early data collectors whose objectives include documenting information related to the incident. it may be used by law enforcement personnel, safety officials, insurance adjusters and other interested parties. The document identifies categories of scene physical features that deteriorate relatively quickly and recomends documentation task priorities. Detailed methods of collecting data are not part of this document. However, some widely used methods are described in the references in Seciton 2.
This SAE Recommended Practice provides guidelines for procedures and practices used to obtain and record measurements and to analyze and present results of frictional drag tests of a vehicle with its brakes fully applied at a given roadway location. It is for use at accident sites and test sites and is applicable to straight-line stopping of vehicles such as passenger cars, light trucks and vans under fully braked conditions including locked-wheel skids for vehicles with a conventional braking system and for vehicles with full or partial antilock braking systems (ABS). The average deceleration resulting from a given series of tests is intended to be representative of a frictional drag factor for the conditions under which the test was conducted such as the type of vehicle, type and condition of tires, roadway material and roadway surface conditions. The frictional drag factor is intended to conform to use with the stopping distance formula (Fricke, 1990) as stated in Equation 1.
Experimental Method for Extracting Dominant Suspension Mode Shapes Coupled with Automotive Interior Acoustic Mode Shapes
A finite element (FE) model of vibro-acoustic coupling analysis, such as a vehicle noise and vibration, is utilized for the improvement of the performance in the vehicle development phase. However, the accuracy of the analysis is not enough for substituting a prototype phase with a digital phase in the product development phases. Therefore, conducting the experiments with the prototype vehicle or the existed production vehicle is still very important for the performance evaluation and the model validation. The vehicle noise transfer function of the road noise performance cannot be evaluated with the existed excitation equipment, such as the 3 or 6 directional electromagnetic shaker. Therefore, this paper proposes new experimental method to measure the road noise vehicle transfer function. This method is based on the reciprocity between the tire contact patch and the driver's ear location.
Investigation of Tire-Road Noise with Respect to Road Induced Wheel Forces and Radiated Airborne Noise
Abstract Low interior noise levels in combination with a comfortable sound is an important task for passenger cars. Due to the reduction of many noise sources over the last decades, nowadays tire-road noise has become one of the dominant sources for the interior noise. Especially for manufactures of luxury cars, the reduction of tire-road noise is a big challenge and therefore a central part of NVH development. The knowledge of the noise transmission behavior based on the characteristics of the relevant sources is a fundamental of a modern NVH - development process. For tire-road noise the source characteristics can be described by wheel forces and radiated airborne noise. In combination with the related vehicle transfer functions it is possible to describe the noise transmission behavior in detail. A method for estimating wheel forces and radiated airborne noise is presented.
Industry experts at Hyundai and Ford address the opportunities and challenges involved with moving toward composite-intensive vehicles. The Ford Multi-Material Lightweight Vehicle project, a collaboration with the U.S. DOE and Vehma International, illustrates the automaker's efforts to move toward lighter-weight materials such as carbon fiber, aluminum, and advanced high-strength steels.
This SAE Recommended Practice describes the basic content requirements, bar-code specifications, and functional test specifications of a vehicle emission configuration (VEC) label. On the vehicle, the VEC label is to be mounted under the hood in a readily accessible location for use of a bar-code scanning device. This document specifies a permanent vehicle emission configuration label that can be automatically identified through a bar-coded format.
This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the installation, inflation, inspection, and maintenance of aircraft tires as well as criteria for the maintenance of the operating environment so as to achieve the purpose stated in 1.1. (Definitions of terms related to aircraft tires are found in 2.2.)
This SAE Recommended Practice provides guidelines for procedures and practices used to obtain and record measurements and to analyze the results of the critical speed method. It is for use at accident sites using manual or electronic measurements. The method allows for many unique factors and the recommended procedure will permit a consistent use of the method in order to reduce errors and uncertainty in the results. The results from the critical speed formula should always, when possible, be compared to other accident reconstruction methodologies. When different accident reconstruction methods are used, the uncertainty of each method should be analyzed and presented.
This SAE Aerospace Information Report (AIR) provides guidelines for the development of landing gear fatigue spectra for the purpose of designing and certification testing of Part 25 landing gear. Many of the recommendations herein are generalizations based on data obtained from a wide range of landing gears. The aircraft manufacturer or the landing gear supplier is encouraged to use data more specific to their particular undercarriage whenever possible.
This SAE Recommended Practice describes a test method for determination of heavy truck (Class VI, VII, and VIII) tire force and moment properties under straight-line braking conditions. The properties are acquired as functions of normal force and slip ratio using a sequence specified in this practice. At each normal force increment, the slip ratio is continually changed by application of a braking torque ramp. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control.
Systems-engineering a new 4x4 benchmark Chrysler Powertrain teamed with AAM to create the industry's most capable, sophisticated-and arguably most fuel-efficient-AWD/4WD driveline. Top engineers talk about their collaboration. Achates aims at 2025 light-truck power After more than a decade of steady development, Achates Power's opposed-piston two-stroke diesel is impressing powertrain experts with its test results and pace of technical progress. Lighter, stronger chassis Development of a new high-strength aluminum casting alloy for the production of suspension components.
This SAE Recommended Practice outlines the qualification testing and performance related criteria of elastomeric boot seals used in constant velocity joint applications. These applications are referred to as front- wheel-drive halfshafts or axles, but can also be utilized in rear-wheel-drive halfshaft applications. For additional information regarding CV joint systems and their applications refer to SAE AE-7 "Universal Joint and Driveshaft Design Manual." The grease type and grease quantities, clamps and clamping mechanisms of an assembly are critical and considered to be the same as OEM, service, or aftermarket designation. Although joint lubricating grease and clamping mechanism are not addressed in this document, they are critical to a total system performance.
The following definitions and illustrations are intended to establish common nomenclature and terminology for universal joints and driveshafts used in various driveline applications. In addition, useful guidelines are included for the application of universal joints and driveshafts. For more specific details, see Universal Joint and Driveshaft Design Manual, AE-7.
Starting from the fundamentals of brakes and braking, Braking of Road Vehicles covers car and commercial vehicle applications and developments from both a theoretical and practical standpoint. Drawing on insights from leading experts from across the automotive industry, experienced industry course leader Andrew Day has developed a new handbook for automotive engineers needing an introduction to or refresh on this complex and critical topic.
Existing multi-axle steering system designs generally use the deterministic optimization method without considering the uncertainties during the design process; therefore an actual steering movement may deviate from the ideal movement calculated by some mathematical models. In order to make design results have less sensitive to the uncertainties in the design process, some uncertainties need be taken into account at the early design stage. This paper proposes a robust optimization design method for a double front axle steering system (DFASS) of heavy trucks based on Monte Carlo method. The DFASS consists of two trapezoidal steering mechanisms (TSM) and one rocker system, and the optimization objectives of DFASS include the minimum mean value and variance of the maximum turning angle error of the TSM and rocker system. In addition, the robust optimization model includes 13 design variables which are all geometry parameters of DFASS and represented by normal distribution.
Subjective Rating Scale for Evaluation of Noise and Ride Comfort Characteristics Related to Motor Vehicle Tires
This SAE Recommended Practice establishes a rating scale for subjective evaluations of noise and discomfort in motor vehicles. Through test procedures utilizing specific vehicles on specific roads, the scale may be utilized to assess the relative contributions of tires to noise and discomfort. The noise and ride comfort characteristics attributed to automotive tires have traditionally been estimated by subjectively assigning number designations (commonly on a 1 to 10 scale) to the audible and tactile sensations observed while traversing a given road course in a vehicle equipped with the tires under evaluation. Regardless of advances in objective measurements of tire properties related to noise and discomfort, subjective evaluation will continue to be necessary for the purpose of establishing the significance of such measurements.
This SAE Recommended Practice establishes a uniform procedure for a flat-road simulation of a mountain-fade test of the brake systems of light-duty trucks and multipurpose passenger vehicles up to and including 4500 kg (10 000 lb) GVW and all classes of passenger cars. The purpose of this test code is to establish brake system characteristics while simulating a mountain descent. This procedure is intended to be used to evaluate the following characteristics of a brake system: a. Brake temperature relative to fluid boil b. Fade resistance and reserve pedal travel c. Overall structural durability d. Subjective stability
This procedure provides for the measurement of the sound generated by a test tire, mounted on a single-axle trailer, operated at multiple speeds. The procedure describes test practices for both United States and International practices. Specifications for the instrumentation, the test site, and the operation of the test apparatus are set forth to minimize the effects of extraneous sound sources and to define the basis of reported sound levels.
This SAE Standard covers molded rubber boots used as end closures on drum-type wheel brake actuating cylinders to prevent the entrance of dirt and moisture, which could cause corrosion and otherwise impair wheel brake operation. The document includes performance tests of brake cylinder boots of both plain and insert types under specified conditions and does not include requirements relating to chemical composition, tensile strength, or elongation of the rubber compound. Further, it does not cover the strength of the adhesion of rubber to the insert material where an insert is used. The rubber material used in these boots is classified as suitable for operation in a temperature range of -40 to +120 degrees C +/-2 degrees C (-40 to +248 degrees F +/-3.6 degrees F).
An understanding of the flow around a tire in contact with the ground is important when designing fuel-efficient tires as the aerodynamic drag accounts for about one third of an entire vehicle's rolling loss. Recently, non-pneumatic tires (NPTs) have drawn attention mainly due to their low rolling resistance associated with the use of low viscoelastic materials in their construction. However, an NPT's fuel efficiency should be re-evaluated in terms of aerodynamic drag: discrete flexible spokes in an NPT may cause more aerodynamic drag, resulting in greater rolling resistance. In this study, the aerodynamic flow around a non-pneumatic tire in contact with the ground is investigated for i) stationary and ii) rotating cases using the steady state Reynolds-Averaged Navier-Stokes (RANS) method. A sensitivity analysis was carried out with a varying mesh density. The flow into cavity by the discrete spoke geometry of the NPT does not significantly affect the overall aerodynamic drag.
Tie rod end clearance is an important parameter influencing automobile stability under slalom maneuver. In this paper the steering mechanism is simplified into a plane linkage mechanism and an analysis of the effects on vehicle stability exerted by kinematic pair clearance under slalom maneuver is also presented. A 4DOF mathematical model of vehicle maneuvering system is thus being built. On the basis of this model, we adopt the numerical analysis method to conduct a simulated analysis about the stability of prototype vehicle side slip angle as the clearance parameter changes. According to the results, vehicle slalom dynamics behaviors manifest itself in shifting from single cycle to chaos directly. With the increase in clearance, nearly no change is displayed in the upper critical frequency of vehicle slalom instability. However, an increasing rise is shown in the lower critical frequency.
Variable Damping - One Solution for Solving the Conflict between Driving Safety and Comfort for Commercial Vehicle
Abstract Variable Damping systems for commercial vehicle applications have been in the market for several years now. The systems modify damping according to the actual demand within milliseconds. This reduces vertical accelerations which lead to improved comfort while maintaining vehicle stability and safety at the same time. Driver, cargo and vehicle are better protected. The technical effort for variable damping systems was in the past rather high and affected a limited market penetration. On the other side the used control algorithms did not tap the full potential of the system performance. New concepts, like integration of sensors or concentration on the most relevant axle, in combination with new control algorithms, simplifies the systems architecture and improves the performance. Besides the functional advantages, the system improves vehicle efficiency as it reduces the energy dissipated by the dampers. This energy would have to be generated by the engine.
Abstract Automotive industry has shown, in the recent years, a dramatically increase of competition at emergent markets. The incoming of new Brands, for example in the Brazilian market, is causing the OEMs to decrease costs while increase quality, which represents a big challenge nowadays. In this challenging scenario, virtual simulation has become mandatory. While cutting costs since no physical prototypes are required, virtual models also reduces development time. Time to time, as computers processing capacity grows, virtual models are becoming more and more accurate, being able to capture even high non-linear phenomena, which ten years ago would not be feasible. It is also known the natural tendency of vehicle dynamics engineers to develop shock absorber tuning only by means of subjective evaluation. Many reasons can be raised to this tendency, but one of them is the lack of representation of the entire shock absorber behavior in the virtual models.