Browse Topic: Vehicle roofs

Items (31)

3D-Printed Reactor Core Makes Solar Fuel Production More Efficient

TBMG-5219312/01/2024

In recent years, engineers at ETH Zurich have developed the technology to produce liquid fuels from sunlight and air. In 2019, they demonstrated the entire thermochemical process chain under real conditions for the first time, in the middle of Zurich, on the roof of ETH Machine Laboratory. These synthetic solar fuels are carbon neutral because they release only as much CO2 during their combustion as was drawn from the air for their production. Two ETH spin-offs, Climeworks and Synhelion, are further developing and commercializing the technologies.

Reinforcement of Low-Frequency Sound by Using a Panel Speaker Attached to the Roof Panel of a Passenger Car

2020-01-157006/03/2020

The woofer in a car should be large to cover the low frequencies, so it is heavy and needs an ample space to be installed in a passenger car. The geometry of the woofer should conform to the limited available space and layout in general. In many cases, the passengers feel that the low-frequency contents are not satisfactory although the speaker specification covers the low frequencies. In this work, a thin panel is installed between the roof liner and the roof panel, and it is used as the woofer. The vibration field is controlled by many small actuators to create the speaker and baffle zones to avoid the sound distortion due to the modal interaction. The generation of speaker and baffle zones follows the inverse vibro-acoustic rendering technique. In the actual implementation, a thin acrylic plate of 0.53ⅹ0.2 m2 is used as the radiator panel, and the control actuator array is composed of 16 moving-coil actuators. The shape of the desired speaker zone is an ellipse, and the required

Lee, Ki-Ho, Cho, Munhwan, Ih, Jeong-Guon

Dynamic Stiffness Investigation of an Automotive Body-in-White by Utilizing Response Surface Methodology

2018-01-147906/13/2018

Noise, vibration, and harshness (NVH) attribute is needed to be included in the vehicle structure design since improving the NVH characteristics enhances the ride quality experienced by the occupants. In this regard, an efficient method was proposed to investigate the structural dynamic response of an automotive body considering low-frequency NVH performances. Moreover, the improvement of an automotive structure under the constraint of NVH behavior was investigated by using the design of experiments (DOEs) method. The DOEs methodology was for screening of the design space and generating approximation models. Here, the thicknesses of panels consisting of a body-in-white (BIW) of an automotive were employed as design variables for optimization, whose objective was to increase the first torsional and bending natural frequencies. Central composite design (CCD) for DOEs sampling and response surface methodology (RSM) were employed to optimize the dynamic stiffness. Moreover, the effects of

Abbasi, Milad, Fard, Mohammad, Khalkhali, Abolfazl

Automotive Engineering: March 2018

18AUTP0303/08/2018

Truck Tech War! Ford, GM, and Ram arm their profit-pumping half-ton pickups for the 2020s' efficiency battle. Mobility mecca: WCX 2018 Provocative thought leaders, emerging disruptors, and the industry's best networking and career guidance all under one big roof: the 2018 SAE World Congress Experience is coming April 10-12. Mercedes adopts Harman UX for A-Class The 'smart' architecture is capable of OTA updates and features more-accurate voice recognition. Spark of genius Mazda's Skyactiv-X-the nexus of gasoline and diesel tech-remains on track for 2019 production. We test-drive recent prototypes to check development status. Taking aim at the drowsy-driver threat Hyundai Mobis is leveraging Level 4 tech to move 'departed' drivers safely off the road. Editorial: Fear and loathing on the path to Level 4 driving Supplier Eye Variability, risk and the value stream The Navigator How will automated vehicles deal with potholes? SAE Standards News SAE-ISO Joint Working Group engaged in SAE

Closed Wheel Race Vehicle Aerodynamic Lift-Off

2017-01-151603/28/2017

Although, the implementation of lift-off prevention devices such as the NASCAR roof flaps have greatly reduced the frequency and severity of race vehicle aerodynamic lift-off incidents, airborne incidents still occur occasionally in motorsports. The effectiveness of existing lift-off prevention measures and future trends in lift-off prevention are addressed in this paper. The results and analysis presented in this paper will be of paramount interest to race vehicle designers and sanctioning bodies because the effects of aerodynamics on vehicle lift-off need to be comprehended, but there exists a scarcity of reliable data in this area.

Honeycutt, Daniel B., Uddin, Mesbah

Assessment of Broadband Noise Generated by a Vehicle Sunroof at Different Flow Conditions using a Digital Wind Tunnel

2015-01-232106/15/2015

For the automotive industry, the quality and level of the wind noise contribution has a growing importance and therefore should be addressed as early as possible in the development process. Each component of the vehicle is designed to meet its individual noise target to ensure the wind noise passenger comfort level inside the vehicle is met. Sunroof broadband noise is generated by the turbulent flow developed over the roof opening. A strong shear layer and vortices impacting on the trailing edge of the sunroof are typical mechanisms related to the noise production. Sunroof designs are tested to meet broadband noise targets. Experimentally testing designs and making changes to meet these design targets typically involves high cost prototypes, expensive wind tunnel sessions and potentially late design changes. To reduce the associated costs as well as development times, there is strong motivation for the use of a reliable numerical prediction capability early in the vehicle design

Oettle, Nicholas, Bissell, Andrew, Senthooran, Sivapalan, Meskine, Mohammed

Aerodynamic Drag Reduction on a Simple Car-Like Shape with Rear Upper Body Taper

2013-01-046204/08/2013

Various techniques to reduce the aerodynamic drag of bluff bodies through the mechanism of base pressure recovery have been investigated. These include, for example, boat-tailing, base cavities and base bleed. In this study a simple body representing a car shape is modified to include tapering of the rear upper body on both roof and sides. The effects of taper angle and taper length on drag and lift characteristics are investigated. It is shown that a significant drag reduction can be obtained with moderate taper angles. An unexpected feature is a drag rise at a particular taper length. Pressure data obtained on the rear surfaces and some wake flow visualisation using PIV are presented.

Howell, Jeff, Passmore, Martin, Tuplin, Simon

Design Studio Creates Pods and Microphone for Rock Tour

TBMG-1418305/01/2012

Stratasys, Inc. Eden Prairie, MN

Stefan Land of Inteva Roof Systems interview at SAE 2012 World Congress

1149804/26/2012

At the SAE 2012 World Congress, Stefan Land, Vice President and Executive Director of Roof Systems at Inteva Products, discussed with SAE Magazines a range of roof-system technology trends such as increased modularization and usage of lightweight materials, along with collaborative product-development efforts with Inteva's Interior Systems group to enhance the overall interior experience.

Test Port for Fiber-Optic-Coupled Laser Altimeter

TBMG-1055007/01/2011

A test port designed as part of a fiber-optic-coupled laser altimeter receiver optical system allows for the back-illumination of the optical system for alignment verification, as well as illumination of the detector(s) for testing the receiver electronics and signal-processing algorithms. Measuring the optical alignment of a laser altimeter instrument is difficult after the instrument is fully assembled. The addition of a test port in the receiver aft-optics allows for the back-illumination of the receiver system such that its focal setting and boresight alignment can be easily verified. For a multiple-detector receiver system, the addition of the aft-optics test port offers the added advantage of being able to simultaneously test all the detectors with different signals that simulate the expected operational conditions.

Microinverters Are Launching a Solar Renewable Revolution

TBMG-990905/01/2011

Given that solar-photovoltaic (PV) generating technology has been around for decades, one might think its general application in commercial and consumer circles might be a little more pervasive. After all, it is clean, safe, and relatively simple. Ask any expert and it’s likely you’ll get a litany of reasons why it has not gained more general acceptance — implementation costs, tricky installation aspects, long ROI, performance, and reliability are just a few. Fortunately, there is a game-changing technology — microinverters — that is ready to push solar PV’s acceptance and application past many of the current barriers.

Development of Liftgate Hinge-to-Roof Sealing Gasket Material for Uncoated Steel Roof Panels

2011-01-007204/12/2011

The sealing of a lift gate hinge to the body structure is necessary to avoid both the onset of corrosion and to avoid water intrusion into the interior compartment. The hinge-to-body interface typically involves horizontal metal-to-metal surface contact, creating the perfect environment for moisture entrapment and corrosion initiation. The choice of body panel material (uncoated (bare) steel vs. coated (galvanized) steel) drives different sealing approaches especially when considering corrosion avoidance.

Corman, Carl, Yergin, Mark, Kussmaul, Andy, Conrad, Lou, Martin, Gregory

Method for Detecting Planar Surfaces in Outdoor Urban Environments

TBMG-581710/01/2009

The ability to detect and recognize buildings is important to a variety of vision applications operating in outdoor urban environments. These include landmark recognition, assisted and autonomous navigation, image-based rendering, and 3D scene modeling. The problem of detecting multiple planar surfaces from a single image has been solved with this technology.

Vehicle Roof Strength Test Procedure

J374_200905 (Historical)05/22/2009

This SAE Recommended Practice establishes a uniform laboratory test method to evaluate the strength characteristics of roof systems. The test procedure is intended to provide reliable and repeatable results and to permit numerical comparisons. A test is conducted in which the vehicle roof system is loaded under controlled laboratory conditions. Structural strength measurements are obtained under load application angles chosen to concentrate forces on the forward portions of the roof panel and roof supporting structure.

Impact and Rollover Test Procedures Standards Committee

A Springback Compensation Study on Chrysler 300C Stamping Panels Using LS-DYNA®

2008-01-144304/14/2008

Springback compensation studies on a few selected auto panels from the hot selling Chrysler 300C are presented with details. LS-DYNA® is used to predict the springback behavior and to perform the iterative compensation optimization. Details of simulation parameters using LS-DYNA® to improve the prediction accuracy are discussed. An iterative compensation algorithm is also discussed with details. Four compensation examples with simulation predictions and actual panel measurement results are included to demonstrate the effectiveness of LS-DYNA® predictions. An aluminum hood inner and a high strength steel roof bow are compensated, constructed and machined based on simulation predictions. The measurements on actual tryout panels are then compared with simulation predictions and good correlations were achieved. Iterative compensation studies are also done on the aluminum hood inner and the aluminum deck lid inner to demonstrate the effectiveness of LS-DYNA® compensation algorithm.

Hu, Yang, Nagarajarao, Manjunath S., Zhu, Xinhai

Passive Control and Local Structural Modification of a Mechanical System Through the Application of High Stiffness Double Layer Dampers

2007-01-235105/15/2007

A study on a passive modal control to be applied to a generally constrained mechanical system is presented, able to cut down frequency peaks in a selective way. A preliminary modal analysis is needed in order to define the system eigenvalues and eigenvectors; then, Damping, Stiffness and Mass experimental matrices can be obtained. Starting from these data, the developed methodology allows to define a damping matrix able to modify the local and global structural modes. In order to validate the reliability of the theoretical model, a simple five degrees of freedom model was first examined, with known stiffness and mass matrices, and a solution for a chosen damping matrix was checked. Successively the same solution was verified giving the theoretical model incomplete information regarding the eigenvalues and eigenvectors matrices. Having validated the theoretical model on a simple system, the methodology was applied to a car roof, realizing a modal modification starting from partial

Giovanni, Visconte

Letting the sun shine in

AUTODEC06_0312/01/2006

Increased modularity and reduced mass and complexity are the focus of convertible-top system engineers. Watching the hardtop roof of the 2007 BMW 3 Series convertible retract is like watching a mechanical ballet. With the push of a button, the car's greenhouse smoothly divides into three main sections, its panels quietly folding, flipping, and eventually nesting together in a neat package hidden within the trunk. Total elapsed time of deployment: 22 seconds. And with the roof retracted, an impressively high 60% of the car's trunk volume is retained for cargo.

Brooke, Lindsay

Radio System for Locating Emergency Workers

TBMG-63807/01/2003

A system based on low-power radio transponders and associated analog and digital electronic circuitry has been developed for locating firefighters and other emergency workers deployed in a building or other structure. The system has obvious potential for saving lives and reducing the risk of injuries.

Vehicle Roof Strength Test Procedure

J374_200201 (Historical)01/17/2002

Impact and Rollover Test Procedures Standards Committee

Control System for Steerable, Rooftop-Mounted Antenna

TBMG-3227605/01/1998

An excerpt from JPL Document D-12104 presents additional information on the control system of a steerable microwave antenna that is mounted on the roof of a land vehicle and used to communicate with a geostationary satellite. The antenna and control system were described previously in "Steerable K/Ka-band Antenna for Land-Mobile Satellite Applications" NASA Tech Briefs, Vol. 18, No. 1 (January 1994), page 28. Under control by a computer mounted in the vehicle, a motor turns a rotary table to aim the antenna in azimuth toward the satellite, which transmits a pilot-tone signal that serves as an aiming beacon. (The radiation pattern of the antenna is wide enough in elevation so that steering in elevation is unnecessary.) Once the pilot tone has been acquired, an inertial turn-rate sensor mounted in the vehicle provides most of the information needed by an open-loop control subsystem that keeps the antenna pointed toward the satellite as the vehicle moves. Drift of the inertial-sensor bias

Vehicle Roof Strength Test Procedure

J374_199710 (Historical)10/01/1997

Impact and Rollover Test Procedures Standards Committee

Vehicle Roof Strength Test Procedure

J374_199105 (Historical)05/01/1991

Impact and Rollover Test Procedures Standards Committee

Inverted Vehicle Drop Test Procedure

J996_19910101/01/1991

Wide Dispersion, Super Thin Speaker Utilizing A Convex Diaphragm

87014302/01/1987

Of all the components associated with ideal sound field reproduction in the automotive environment, the role placed by the speaker is perhaps the most critical yet most difficult to accomplish. This paper deals with the development of a new, single cone speaker which goes one step closer toward that goal by use of novel, inverted-conical diaphragm design which provides dramatically improved sound dispersion performance (Dispersion: 180°, 10Khz, −10dB), while maintaining wide frequency response range (80Hz to 20Khz). Furthermore, to enhance applicability to the automotive environment, the new design successfully reduces mounting depth requirement and overall speaker height (9mm and 25mm respectively) and weight (170g for 12cm diameter). The super thin and lightweight construction makes possible new mounting locations like the sunvisor or roof. This greater latitude in speaker placement provides new flexibility in optimizing sound field reproduction in the car interior.

Kawahara, Teru, Yano, Hiroshi

Development of a Rigid Passenger Safety Compartment Made of Composite Material-Application for Front Door Frames

86027803/01/1986

Based an extensive preparatory work and analyses, suggestions have been drawn up with regard to solutions for front door frames in the following regions:- door hinge mountings, seat belt anchorage mountings of B pillars, cross sections for the top of A pillars. At the same time as the design work, FEM calculations should be carried out to ensure optimization of the concepts. Economy reasons and experiences in production runs point towards a very strong fibre glass-reinforced door frames manufacutred in the SMC procress. The complete door frame is examined in comparison with geometrically similar sheet metal parts on a test frame and in the vehicle.

Voy, Christian, Morsch, Dieter

Integrated Panel and Skeleton Automotive Structural Optimization

81131711/01/1981

Previous work in structural optimization for the automotive structure has been limited to beam models of the major load-carrying structure. This was primarily done to reduce the amount of computer resources required to minimize the mass. In this study, techniques necessary to include a moderately complex representation of the panels are developed in which some compromises between model fidelity and solution time must be accepted. As an example, plate elements have been included in a vehicle structural optimization model to represent the roof, floor, dash, motor compartment, and rear quarter. Minimum mass designs subjected to stress, displacement, and frequency constraints are obtained by structural optimization. It was found that most panels were at minimum gage in the optimum design. This suggests that these panels are designed by local criteria as opposed to being controlled by global load and stiffness criteria. A few panels in the highly stressed areas are affected by the global

Miura, H., Lust, R. V., Bennett, J. A.

Hungarian Research Into the Strength of Bus Roofs

78509201/01/1978

The paper examines the safety provided by bus roofs in accidents. Test results show that static, vertical loads have little to do with actual accident results and that corresponding tests are not indicative of security. A diagonal force of recoil acts upon the roof edge in accidents; the components of this force in the roof plane determine the resulting plastic deformation. Consequently, load-bearing characteristics and energy absorption properties must be tested in an oblique direction. Based on the results of the crash- and laboratory tests cited, suggestions for roof improvements were implemented. Currently, some buses are being factory-equipped with rollbars as a result of this research. Standard testing procedures were established for accident-safety. Bus models which pass this test offer a certain level of security which is generally higher than that currently afforded. However, many possible influences were not taken into account and the present testing procedure must be further

Voith, Andras, Vessey, Tamas

Vehicle Roof Strength Test Procedure

J374A_197402 (Historical)02/01/1974

Impact and Rollover Test Procedures Standards Committee

Laboratory Testing for Evaluation of Passenger Car Roof Intrusion Resistance Strength

72022502/01/1972

A test facility and procedure have been developed for use in evaluating passenger car roof intrusion resistance strength in the laboratory. This facility and procedure produce reliable and repeatable data which permit numerical comparison of separate test bodies or vehicles and automatically indicate performance through the use of a X,Y,Y plotter. The test facility consists of three parts: an adjustable structural frame for supporting the test unit in position for test, a hydraulic loading system for applying the load, and instrumentation for lead and placement readout. A complete description of the facility is presented, with emphasis on the advantages of dual readout of data. The test procedure is also detailed, with description of sample preparation, mounting the test unit, and the graphical addition of curves.

Petty, Johnny M.

Static Load Test Code for School Bus Body Structure

65071702/01/1965

A static load test code for school bus body structure was developed to furnish a method of ascertaining the deflection of the body at several points. This offers to school transportation personnel on the state and national levels a code to use as reference in school bus body specifications for the purpose of restricting the maximum limits of deflection of roof assemblies, side wall assemblies, and floor assemblies. The body manufacturer is provided with a standard base for design purposes, without limitations of material types, material gages, or structural sectional shapes.

Rumph, W. C.

HOW TO GAIN CAR RIGIDITY WITH CONVERTIBLE BODIES

52007001/01/1952

ALLEN, E. L.

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