Terms:
SAE International Journal of Passenger Cars Mechanical Systems
AND
5
AND
3
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

ERRATUM: Basilar Skull Fractures by Crash Type and Injury Source

SAE International Journal of Passenger Cars - Mechanical Systems

ProBiomechanics LLC-Chantal Parenteau, David C. Viano
  • Journal Article
  • 2011-01-1126ERR
Published 2012-07-15 by SAE International in United States
The legends of Table 6 and Table 7, found on pages 924 and 925, did not properly reference multiple characters used within the tables.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

NVH Challenges and Solutions for Vehicles with Low CO2 Emission

SAE International Journal of Passenger Cars - Mechanical Systems

AVL LIST GmbH-Stephan Brandl , Bernhard Graf, Alfred Rust
  • Journal Article
  • 2012-01-1532
Published 2012-06-13 by SAE International in United States
Driven by worldwide climate change, governments are introducing more stringent emission regulations with particular focus on fuel saving for CO₂ emission reduction. Downsizing and weight reduction are two of the main drivers to achieve these demanding regulations. Both aspects however might have a strong negative effect on the overall vehicle NVH behavior.Weight reduction directly influences NVH due to reduction of absorption and damping material and due to light-weight design affecting the dynamic responses of powertrain and vehicle structures. Engine downsizing however has multiple negative effects on NVH. Beside higher vibrations and speed irregularities due to lower cylinder numbers and displacements also reduction of sound quality is a critical topic that will be handled within this publication.The first part of this publication will focus on excitation of engines with different number of cylinders, an alternative mounting solution for 3-cylinder engines and an overview on the changes of sound quality for downsized engines.In the second part two solutions for vehicles with downsized engines will be presented. The first vehicle is equipped with a 4-cylinder engine and electrical…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Tire-Road Noise Analysis of On-Road Measurements under Dynamic Driving Conditions

SAE International Journal of Passenger Cars - Mechanical Systems

HEAD acoustics GmbH-Roland Sottek, Bernd Philippen
  • Journal Article
  • 2012-01-1550
Published 2012-06-13 by SAE International in United States
The powertrain noise of cars has been reduced in the last decades. Therefore in many cases, rolling tires have increasingly become the dominant sources of vehicles' interior noise. For sound design or a reduction of tire-road noise it is important to know the individual noise shares of the tires and their transfer paths. Authentic tire-road noise can only be measured on a real road, not on a roller dynamometer. So far measurements have been performed during a coast-down on the road with the engine switched off, avoiding the influence of engine noise.Operational Transfer Path Analysis (OTPA) can be used to remove the uncorrelated wind noise, and to synthesize structure-borne and airborne tire-road noise based on input signals measured with microphones at the tires and a triaxial accelerometer at each wheel carrier. Simultaneously, the interior noise is recorded by an artificial head.Acceleration, deceleration or other driving maneuvers with the engine running can lead to different tire noises. In this case the conventional method cannot be applied because the engine sound is measured at the source (tires)…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigations of the Influence of Lower Frequency Aerodynamic Noise on Interior Cruise and Exterior Pass-By Sound Levels

SAE International Journal of Passenger Cars - Mechanical Systems

Illingworth & Rodkin Inc.-Paul R. Donavan
  • Journal Article
  • 2012-01-1554
Published 2012-06-13 by SAE International in United States
The results of a series of tests were performed that are used to investigate the contribution of aerodynamic noise to lower frequency passenger car interior and exterior cruise noise levels. Wind tunnel measurements were used to isolate aerodynamic noise from tire-pavement and engine noise and to indicate that the vehicle underbody is a significant source region for both interior and exterior noise. Comparing interior on-road measurements to the wind tunnel results, it was found that aerodynamic noise was slightly less than an equal contributor to cruise noise averaging 4.8 dB lower than the road levels between 50 and 400 Hz at a speed of 80 km/h. At 140 km/h, the difference dropped to 2.3 dB indicating that the aerodynamic noise was the major contributor. For exterior pass-by, aerodynamic noise levels were found to account for almost all of the noise measured during coast-by conditions in the frequency range from 50 to 400 Hz at 97 km/h. This finding was substantiated by additional pass-by testing using different tires on a variety of pavements. It was further…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Improved Comfort Analysis and Drivability Assessment by the Use of an Extended Power Train Model for Automatic Transmissions

SAE International Journal of Passenger Cars - Mechanical Systems

AVL LIST GmbH-Klaus Meitz
Gesellschaft für Industrieforschung mbH-Sigrid Klinger
  • Journal Article
  • 2012-01-1529
Published 2012-06-13 by SAE International in United States
The new generation of automatic transmissions is characterized by a compact and highly efficient design. By the use of a higher overall gear ratio and lightweight components combined with optimal gear set concepts it is possible to improve significantly fuel consumption and driving dynamics. Precise and efficient real time models of the whole power train including models for complex subsystems like the automatic transmission are needed to combine real hardware with virtual models on XiL test rigs. Thereby it's possible to achieve a more efficient product development process optimized towards low development costs by less needed prototypes and shorter development times by pushing front loading in the process.In this paper a new real time model for automatic transmissions including approved models for the torque converter, the lock-up clutch and the torsional damper are introduced. At the current development stage the model can be used for comfort analysis and drivability assessment. Thereby various operating conditions including motored engine and an open, slipping or locked clutch condition can be simulated. For the torque converter a map based,…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

TPA and NVH Prognosis - Application to Mercedes Benz Car Development of New Hybrid Methods Coupling Digital Simulation with Prototype Testing Results

SAE International Journal of Passenger Cars - Mechanical Systems

Daimler AG-Karsten Finger, Michael Brandes, Edmund Schmidt
  • Journal Article
  • 2012-01-1535
Published 2012-06-13 by SAE International in United States
Digital NVH development has become a common tool for any acoustic engineer. Vehicles in their early development stages are nowadays mainly described and validated as digital models. However there still remain needs for improvement in the domains of acoustic and vibration prediction, as instance: refining models, addressing intricate systems, and CAE resistant phenomena. In a background of increasing modularity and process transfers, hybrid methods coupling with testing results, have shown a great potential for improving the quality of NVH prognosis and development quality.Mercedes-Benz passenger car division has developed, tested and introduced a new engineering tool, based on the classical TPA applications coupled with hybrid simulation techniques. This toolbox is used to enhance the prognoses of acoustic interior noise and vibration comfort.The actual NVH development process for engines and vehicles is described with main quality gates and objectives, showing when established or new methods come into use. In order to reach an effective operational level of the toolbox, it was necessary to standardize and automate thoroughly the whole acquisition and processing chain. This meant defining a…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Further Development of the PNCA: New Panel Noise Contribution Reference-Related (PNCAR)

SAE International Journal of Passenger Cars - Mechanical Systems

Microflown Technologies BV-Andrea Grosso, Daniel Fernandez Comesana, Hans-Elias De Bree
  • Journal Article
  • 2012-01-1539
Published 2012-06-13 by SAE International in United States
The Panel Noise Contribution Analysis (PNCA) is a well-known methodology for an airborne Transfer Path Analysis (TPA) in car interior. Pressure contribution from the individual panels at a reference point can be very accurately calculated. Acoustic Trim package treatment can therefore be optimized in terms of frequency and panel area which saves money and time. The method uses only one type of sensors so called particle velocity probes for measuring source strength as well as transfer function (with a reciprocal measurement).Traditionally the PNCA makes use of a big amount of probes at fixed points (about 50) hence non-stationary conditions can be measured as well. Typically the measurement is performed in 3 sessions resulting in 150 individual panels. Because of the low spatial resolution the method can only be used at mid-low frequency range.The new Panel Noise Contribution Analysis Referenced (PNCAR) implements a new post-processing technique which uses a reference sensor in order to extract the relative phase information for the individual panel and frequency of interest. This technique makes it possible to use a limited…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Elaborate Measuring System for Sensitivity Analyses and In-Depth Investigations of a Squealing Brake System

SAE International Journal of Passenger Cars - Mechanical Systems

Graz University of Technology-Daniel Wallner, Markus Meister
  • Journal Article
  • 2012-01-1541
Published 2012-06-13 by SAE International in United States
Brake squeal is an elusive problem which has been the subject of investigation for many decades, but there is still a lack of knowledge regarding the excitation mechanisms. New vehicle solutions, for instance the electrical vehicle, will have a lower general noise level. Thus, silent brake systems will gain in importance. To obtain such systems, in-depth investigations of the brake disc/pad contact are required.For these investigations a new sensor has been developed. The guide pins of the caliper are replaced by modified ones which measure the friction force. Additionally, eddy current sensors are installed for contact-free measurement of the pad movement. Furthermore, triaxial acceleration sensors are mounted in the disc vents. Thus, it is possible to evaluate the operational deflection shapes of the disc.Next, an extensive sensibility analysis is performed. Parameters such as environmental conditions, friction coefficient and many others are thereby changed. For example shown is the root mean square (RMS) value of the out-of-plane vibration of one acceleration sensor mounted in the brake disc vents. Five revolutions are depicted in the polar axis…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Squeak & Rattle Correlation in Time Domain using the SAR-LINE™ Method

SAE International Journal of Passenger Cars - Mechanical Systems

SAAB Automobile AB-Jens Weber, Ismail Benhayoun
  • Journal Article
  • 2012-01-1553
Published 2012-06-13 by SAE International in United States
A new Squeak & Rattle simulation method was presented at the ISNVH conference 2010 (SAE 201-01-1423). This method, called the SAR-LINE™ method, is based on the evaluation of the relative displacement in time domain due to a random load. A specific challenge for a Squeak & Rattle simulation approach is to correlate the results to a real squeak or rattle phenomenon. This paper presents a new test procedure which enables the correlation between the results of the SAR-LINE™ simulation and the audible rattle occurrence. Three different configurations with increasing complexity were both tested and simulated. A pseudo random signal was used as load and the relative displacement was measured with the Laser Scanning Vibrometer in time domain. The movement in the gap and the rattle sound were recorded in a video sequence. The simulated results along the SAR line can directly be compared with the measured results along the gap. It is shown how the correlation between the rattle occurrence and the simulation results can be performed with the statistical evaluation approach of the SAR-LINE™…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Multi-Objective Optimization of a Car Body Structure

SAE International Journal of Passenger Cars - Mechanical Systems

AGH University-Izabela Kowarska, Tadeusz Uhl
Centro Ricerche Fiat S.C.p.A.-Rosario Raniolo, Marco Danti
  • Journal Article
  • 2012-01-1555
Published 2012-06-13 by SAE International in United States
In the last years engineers have to deal with multiple, often conflicting targets, where improvement of one quantity leads to deterioration of others, therefore it is impossible to obtain simultaneous structure enhancements without automatic optimizations tools. The so-called trade-offs have to be applied, providing less efficient modifications, nevertheless, for all of the design objectives. The Pareto front is a method that helps to determine a set of equipotential designs.In order to explore entire design space, response surface methodology supplemented by genetic algorithms is often used. In the work presented, the Gaussian Processes Methodology and an Adaptive Range Multi-Objective Genetic Algorithm - ARMOGA were implemented. Basing on the solutions obtained by the design of experiment, response surface methodology is used to predict the values of the measured outputs throughout the full range of interest. Since only a reduced number of tests is needed, the overall computational time is strongly reduced. Subsequent application of genetic algorithms, provide the possibility of detailed exploration of established metamodels.In Centro Ricerche Fiat S.C.p.A. an effort of elaborating a novel optimization platform…
Annotation ability available