At Tenneco, we understand the scale of commitment in developing a new vehicle. That’s why we get involved in the development cycle at the earliest stage. From the start, every OEM program is managed by an experienced program manager whose objective is to ensure open and efficient communication with your teams. So if you’re starting out on the development of a new model in your vehicle range, talk to the people able to respond to every possible bump in the road: the development team at Monroe® Intelligent Suspension. The sixth sense for your drive.
Multi-material structures move mpg upward The quest to improve fuel economy is not waning, nor is the desire to achieve higher mpg through the use of just the right lightweight material for the right vehicle application. Cars poised to become 'a thing' Making automobiles part of the Internet of Things brings both risks and rewards. Agility training for cars Chassis component suppliers refine vehicle dynamics at the high end and entry level with four-wheel steering and adaptive damping. SAE 2016 World Congress Preview Technology trends and exhibitor products are highlighted in this special section, which features Toyota's plans for the show floor, tech sessions, and more.
Vehicles that use all four wheels to steer are more agile, easier to park, and safer to drive. In this episode of SAE Eye on Engineering, Editor-in-Chief Lindsay Brooke tests a new prototype four-wheel steering system from supplier ZF-TRW.
This SAE Standard specifies a method for measuring the deflection of friction materials, noise insulators, and disc brake pad assemblies to be used in road vehicles with a Gross Vehicle Weight Rating below 4336 kg. This part of the SAE J3079 includes the test for deflection and creep at various pressures under ambient temperature conditions. This SAE test method differs from SAE J2468 and ISO 6310 in the preload and maximum load applied to the test sample when deflection is measured. It also introduces additional measurements such as for deflection offset, hysteresis, and creep.
Parking Brake Control Identification - Vehicles with Hydraulic Brake Systems and Automatic Transmissions
The scope and purpose of the SAE Recommended Practice is to provide standards for the control and indication of parking brakes in hydraulic braked vehicles over 4540 kg (10000 lb) GVWR. This recommended practice pertains to automatic transmission applications and supplements the SAE J915 recommended practice. This recommended practice does not address parking brake system performance. Parking brake system performance, both static and dynamic conditions, is the responsibility of the OEM vehicle manufacturer or manufacturers that modify the vehicle by adding special vocational required equipment (such as but not limited to outriggers, cranes, etc.).
This SAE Recommended Practice applies to the validation process required for test systems used to measure deflection or compressibility of friction materials and friction material assemblies for passenger cars, light trucks, and commercial vehicles equipped with hydraulic or air brake systems, and using disc or drum brakes.
Developers are starting to adapt complex design simulations into easy to use tablet apps. Could gear box designs using non-linear stress analysis, fatigue predictions, and CFD be coming to your smartphone?
Off-highway hybrids: Opportunities and challenges With oil prices declining and emissions regulations in North America 'stabilized,' is there a place for hybrid powertrains in this new world of cheap oil? Looking for a better image Display advances are helping to reduce operator fatigue. Charging up electrified powertrains Control technologies race forward while batteries improve and adopt standard sizes. Measuring and accounting for suspension TARDEC teamed with SEA Ltd. to develop a system to measure the suspension parameters, center of gravity, and moments of inertia of wheeled vehicles in the never ending quest to model and predict vehicle dynamic behavior. Looking at mobility in 2050 Cuneyt L. Oge begins his term as 2016 SAE International President with a vision about the future of auto- and aero-mobility.
Sensata Technologies introduced its smallest micro-fused strain gauge technology for next-generation brake systems especially designed for hybrid and electric vehicles.
Abstract The design of the conventional passive suspension has always been a compromise between vehicle handling and comfort, which led to the development of the modern active and semi active suspension systems. Amongst these, semi-active suspension has been focus of research in recent years owing to its lesser complexity and less power consumption as compared to active suspension. Semi active suspension uses real time variation in damping coefficient which can be achieved by using various control strategies. It is observed from available literature that Skyhook (for better ride comfort), Groundhook (for better vehicle handling) and Hybrid are most widely used strategies. These strategies use ‘On-Off’ control strategy (i.e. two preset values of damping co-efficient) but a better control over damping coefficients can be achieved using Continuous Control strategy. This paper aims to implement Continuous control strategy using Fuzzy logic for the semi active suspension.
Abstract Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input.
Abstract Steering and suspension system has to be designed properly to achieve improved handling characteristics. Improper design of steering systems will result in steering errors such as bump steer and roll steer. These steering errors results in reduced steering performance. During the design of steering system the tie rod length has to be properly selected to reduce these steering errors. The purpose of the work is to analyze the effects of tie rod length variation on bump steer. Multi body dynamic model of the selected vehicle was created using MSC ADAMS Car software. Ideal design of steering system to achieve zero bump steer was created. The tie rod length was later varied up to 10% to study the effect of varying length on bump steer. Parallel wheel travel analysis was conducted to study the tie rod length variation on bump steer. Acceleration test was conducted on a flat road having bump to analyze the effect of changing tie rod length on steering performance of the vehicle.
A new Michelin tire is an all-season street grabber with technical attributes derived from endurance racing.
Road Hazard Impact Test for Wheel and Tire Assemblies (Passenger Car, Light Truck, and Multipurpose Vehicles)
The test is designed to evaluate the frontal impact resistance of wheel and tire assemblies used with passenger cars, light trucks and multi-purpose vehicles. The test is specifically related to vehicle pothole tests that are undertaken by most vehicle manufacturers. The scope has been expanded to allow the use of a striker that can be angled to preferentially impact the inboard and outboard wheel flange. For side impact of the outboard rim flange only, please refer to SAE J175. This SAE Recommended Practice provides a procedure to test a wheel or a tire and the test failure critiera. The specific test for a vehicle requires input from a pothole test on that vehicle to establish the drop height of the striker used in this test.
This SAE Aerospace Recommended Practice (ARP) covers the functional, design, construction, and test requirements for Automatic Braking Systems. Installation information and lessons learned are also included.
System offers fast response and eliminates piston drag, but hydraulic output to front wheels is still needed for larger cars.
This SAE Recommended Practice covers equipment capabilities and the test procedure to quantify and qualify the shear strength between the friction material and backing plate or brake shoe for automotive applications. This SAE Recommended Practice is applicable to: bonded drum brake linings; integrally molded disc brake pads; disc brake pads and backing plate assemblies using mechanical retention systems (MRS); coupons from drum brake shoes or disc brake pad assemblies. The test and its results are also useful for short, semi-quantitative verification of the bonding and molding process. This Recommended Practice is applicable during product and process development, product verification and quality control. This Recommended Practice does not replicate or predict actual vehicle performance or part durability.
This recommended practice has been developed to assist engineers and designers in the preparation of specifications for the major types of helical compression and extension springs. It is restricted to a concise presentation of items which will promote an adequate understanding between spring manufacturer and spring user of the major practical requirements in the finished spring. Closer tolerances are obtainable where greater accuracy is required and the increased cost is justified. For the basic concepts underlying the spring design and for many of the details see the SAE Information Report MANUAL ON DESIGN AND APPLICATION OF HELICAL AND SPIRAL SPRINGS, SAE HS 795, which is available from SAE Headquarters in Warrendale, PA 15096. A uniform method for specifying design information is shown in the TYPICAL DESIGN CHECK LISTS FOR HELICAL SPRINGS, SAE J1122.
Last year's double-digit hiring spree of engineers continues at Schaeffler as demand in North America intensifies for the supplier's engine, transmission, and chassis technologies.
This SAE Recommended Practice provides basic recommendations for dispensing and handling of SAE J1703 and SAE J1704 Brake Fluids by Service Maintenance Personnel to assure their safe and effective performance when installed in or added to motor vehicle hydraulic brake actuating systems. This document is concerned only with brake fluid and those system parts in contact with it. It describes general maintenance procedures that constitute good practice and that should be employed to help assure a properly functioning brake system. Recommendations that promote safety are emphasized. Specific step-by-step service instructions for brake maintenance on individual makes or models are neither intended nor implied. For these, one should consult the vehicle manufacturer’s service brake maintenance procedures for the particular vehicle. Vehicle manufacturer’s recommendations should always be followed.
This SAE Recommended Practice furnishes sample forms for helical compression, extension and torsion springs to provide a uniform method for specifying design information. It is not necessary to fill in all the data, but sufficient information must be supplied to fully describe the part and to satisfy the requirements of its application. For detailed information, see 'Design and Application of Helical and Spiral Springs - SAE HS 795 SEP82', also 'Helical Compression and Extension Spring Terminology - SAE J1121 NOV75.' Both of these documents use SI (metric) units in accordance with the provisions of SAE J916 MAY85, and so does SAE J1122. Here, however, the U.S. Customary Units (in, lb, psi) have been added in parentheses after each SI Unit for the convenience of the user who must furnish specifications on a project where all requirements are listed in non-metric terms.
In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III). The purpose of this recommended practice is to define standardized symbols that describe the arrangement and function of drivetrain systems and components of all-wheel-drive vehicles. This document presents basic symbols, superimposed symbols and symbols with modifiers. Various vehicle drivetrain schematics are shown with specific component arrangements or general driveline layout to illustrate varying levels of descriptive intent.
This information report provides general guidance for the design considerations, qualification in endurance, strength and fatigue of landing gear using composite components as principle structural elements. The information discussed herein includes the development and evaluation of design data considering: the potential for imbedded manufacturing defects, manufacturing process variations, the component operating environment, potential damage threats in service, rework and overhaul, and inspection processes. This AIR mainly discusses the use of thick composites for landing gear structural components. Considerations and recommendations provided in this AIR may therefore differ greatly from considerations and recommendations found in widely accepted composite design references such as CMH-17 and Advisory Circulars such as AC 20-107(B).
Abstract The disk spring offers the potential of significant weight savings when designed with continuous fiber reinforced composite materials. The internal stresses in a disk spring are ideally suited for composite material application due to their superior resistance to in-plane and bending stresses. In this study, a composite laminate disk spring is designed, analyzed and fabricated to take advantage of the low specific strength and weight and high damage tolerance of composite laminates. The design of the disk composite spring considers effects of the laminate stacking sequence and the geometric variables on the disk spring's mechanical performance. A continuum damage finite element analysis approach is used to understand the damage initiation and evolution as a function of applied load. Experimental analysis and a progressive damage analysis based on virtual crack closure technique are performed to evaluate the damage tolerance of the disk spring under fatigue loadings.
The vehicle dynamics terminology presented herein pertains to passenger cars and light trucks with two axles and to those vehicles pulling single-axle trailers. The terminology presents symbols and definitions covering the following subjects: axis systems, vehicle bodies, suspension and steering systems, brakes, tires and wheels, operating states and modes, control and disturbance inputs, vehicle responses, and vehicle characterizing descriptors. The scope does not include terms relating to the human perception of vehicle response.
This specification covers coiled springs fabricated from carbon-steel wire.
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 °C ± 2 °C (-40 to + 248 °F ± 3.6 °F).
The purpose of this test is to evaluate the axial strength of the nut seat of wheels intended for use on passenger cars, light trucks, and multipurpose vehicles. In addition, a minimum contact area is recommended to ensure enough strength for the rotational force in tightening a nut against the nut seat. While this test ensures the minimum strength of the nut seat, the wheel must also have a degree of flexibility. This flexibility, as well as bolt tension, are important to maintain wheel retention.
Improving heavy-duty engine component efficiencies Cylinder deactivation can improve fuel economy by using a reduced number of cylinders that operate at higher loads and thermal efficiency, while other cylinders are turned off, when the engine operates at partial load conditions. A switching roller finger follower is one of the technologies that help make it work. Pumping up hydraulic capabilities Electrohydraulic advances keep coming as distributed electronics flex their muscle. Tracking the trends in commercial vehicle communications Industry insiders at Molex offer what they think the future may hold for heavy-duty components in 24/7 communications systems. ADAS system validation It is crucial that different advanced driver assistance systems functionalities interact seamlessly with existing electronic control unit (ECU) networks.
Abstract The aim of this investigation is the improvement of the lateral vehicle dynamics by optimizing the rim width. For that purpose, the rim width is considered as a development tool and configured with regard to specified targets. Using a specifically developed method of simulation, the influence of the rim width is analysed within different levels - starting at the component level “tyre” and going up to the level of the whole vehicle. With the help of substantial simulations using a nonlinear two-track model, the dimensioning of the rim width is brought to an optimum. Based on both, tyre and vehicle measurements, the theoretical studies can be proved in practice. As a result, the rim width has a strong influence on the behaviour of the tyre as well as on the overall vehicle performance, which emphasises its importance as a potential development tool within the development of a chassis.
Abstract In ride comfort as well as driving dynamics, the behavior of the vehicle is affected by several subsystems and their properties. When analyzing the suspension, especially the characteristics of the main spring and damper but also rubber bushings are of main importance. Still, the properties of the different components are dependent on the present operating conditions. Concerning rubber bushings, several effects have already been investigated, e.g. dependencies of the transfer function of frequency, amplitude or load history. In this context influences of changes in temperature are often neglected. However, in the following research, the focus specifically lies on determination and analysis of the temperature dependency of rubber bushings. For this purpose, initially the relationship between properties of pure rubber and rubber bushings is described, which serves as a basis for correlating respective temperature dependencies.