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Brake Dynamometer Squeal Noise Test Procedure for Regenerative Systems

The SAE J3211 procedure applies to brake squeal evaluation using single-ended inertia dynamometers for friction couples used on vehicles with regenerative braking systems. This RP applies to squeal noise occurrences for on-road passenger cars and light trucks with a gross vehicle weight rating of 4536 kg or below. The procedure incorporates aspects related to (a) minimum inertia dynamometer capabilties, (b) fixture requirements and setup, and (c) test sequences with emphasis on brake temperatures, brake pressure profiles, and strategies to represent brake blending.

Factory Man

Factory Man is about James Harbour and the epic struggle of the U.S. auto industry to catch up to Japan in quality and productivity. Harbour is a former manufacturing executive who, partly by chance, became the first U.S. expert to study Toyota's operations in Japan. Harbour's consulting firm, Harbour & Associates has gained worldwide recognition for its annual public studies of factory productivity. The Harbour Report is the essential annual scorecard of who is winning the productivity race in the U.S. In 1981, Harbour reported that Toyota could offer a small car for sale in the U.S. at a production cost of $1,500-$1,700 less than the Detroit automakers at that time, a cost advantage of about 30 percent. The impact on Detroit was atomic, and launched the painful, historic effort by the Big Three to catch up, which continues today. James Harbour's story, blunt and accessible, includes a detailed description of how Detroit went astray, beginning right after World War II.

Toyota Kata

This game-changing book puts you behind the curtain at Toyota, providing new insight into the legendary automaker's management practices and offering practical guidance for leading and developing people in a way that makes the best use of their brainpower. Drawing on six years of research into Toyota's employee-management routines, Toyota Kata examines and elucidates, for the first time, the company's organizational routines—called kata—that power its success with continuous improvement and adaptation. The book also reaches beyond Toyota to explain issues of human behavior in organizations and provide specific answers to questions such as: • How can we make improvement and adaptation part of everyday work throughout the organization? • How can we develop and utilize the capability of everyone in the organization to repeatedly work toward and achieve new levels of performance?

Introduction to Dynamics of Rotor-Bearing Systems

This book is written as an introduction to rotor-bearing dynamics for practicing engineers and students who are involved in rotor dynamics and bearing designs. The goal is to provide a step-by-step approach to the understanding of fundamentals of rotor-bearing dynamics. Therefore, the emphasis is on the basic principles, phenomena, modeling, theory, and interpretations of the results. Introduction to Dynamics of Rotor-bearing Systems includes numerous examples, from a single-degree-of-freedom system to complicated industrial rotating machinery, which serve to illustrate fundamental dynamic behaviors. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures.

Lectures of the 32nd International Vienna Motor Symposium

Proceedings from the 32nd International Vienna Motor Symposium now available through SAE International. One of the most prestigious conferences on engine development in the industry today, the International Vienna Motor Symposium, now in its 32nd year, gathers world renowned experts to discuss the current and future state of motor technology. According to Dr. Hans Peter Lenz, president of the Austrian Society of Automotive Engineers, who opened this year’s conference, markets are now in a better position to understand how internal combustion engines and electrified powertrains can actually complement each other. Presenters offered their input and experience in the development of new technologies enabling higher levels of fuel efficiency and power, longer range and a cleaner way for the mobility industry to move forward. The proceedings, available in two volumes and a CD, contain all the technical papers given during the meeting, both in English and in German.
Technical Paper

A Procedure for Evaluating Cycle Emissions from Raw Exhaust Gas Analyses

A procedure has been developed for evaluating equivalent drive cycle emission results from raw exhaust gas emissions data obtained from an engine under test on a computer controlled Vehicle Simulator Engine Dynamometer. The emitted species data is integrated with the air intake flow rate to determine the total mass of emissions, after correcting for the reduction in exhaust gas mass due to precipitation of the moisture of combustion. This procedure eliminates the need for the Constant Volume Sample (CVS) System attached to the vehicle exhaust while undergoing simulated drive testing on a chassis dynamometer to evaluate compliance of the test vehicle with the Australian Design Rules, ADR27 and ADR37. Sources of error with the procedure are examined by comparing the fuel consumption measured using a volumetric technique during the test with that evaluated by a carbon balance procedure as given in the Australian Design Rules.
Technical Paper

Integration of Reliability, Maintainability and Quality Parameters in Design

Synthesizing different customer and functional requirements into an acceptable design configuration within a given space constraints is a challenging task for design engineers. The principles for designing efficiency, noise levels, maneuverability, safety, durability, etc. into the product are well understood. However, designing for reliability, maintainability and quality turns out to be a long-drawn laborious process due to unavailability of simplified design procedures. The author in this paper develops the understanding of reliability, maintainability and quality design principles and methods for products, with specific reference to vehicle designs.
Technical Paper

Guidelines on the Use of Experimental Sea for Modeling and Understanding Road Noise in Cars

Over the last years, SEA has been recognized as a useful tool to model and analyze the high-frequency vibro-acoustic behavior of fully assembled complex structures. This paper discusses the experimental derivation of the loss factor model of a passenger car. The paper outlines the different steps which need to be taken to obtained a fully validated experimental SEA model. This includes the subdivision into subsystems, the PIM measurement campaign, the derivation of the loss factors and their associated confidence levels and the model validation. The paper further details how the experimental SEA model was used to quantify and investigate the airborne and structure-borne contributions to the interior noise level for a road noise test condition. The operational power inputs to the vehicle were indirectly determined from operational response measurements. A contribution analysis showed that airborne noise sources dominated structure-borne noise sources above 500Hz.
Technical Paper

Validation of SEA Models using Measured Modal Power

Statistical energy analysis is generally used to study the vibroacoustic response of systems with high modal densities. The most accurate predictions are obtained at high frequencies where the modal overlap is high and many modes contribute to the response in each frequency band. Under these conditions, the vibrational response is fairly uniformly distributed over frequency and over the spatial extent of the SEA subsystems. Validation of an SEA model at high frequencies can be accomplished by comparing the predictions of average subsystem response with an average formed from measured data at a relatively small number of locations. At lower frequencies, where the modal overlap is not high, the vibrational response shows significant variability over both frequency and location. Large variability makes validation of the models more difficult.
Technical Paper

Practical Applications of SEA CAE Analysis in Vehicle Sound Package Development

Vehicle sound package serves two basic functions: general acoustic insulation and local problem treatment. The former is often done at the up-front phase of the vehicle development process, and the latter at the downstream phase when representative prototype hardware becomes available and specific noise problems are identified. This paper examines the goals and key tasks of practical SEA CAE applications in the two phases of the sound package development process. Topics on CAE model requirement, typical analysis applications, and ways to improve the effectiveness of SEA applications to compliment hardware testing are discussed.
Technical Paper

Analysis of Vehicle Pillar Cavity Foam Block Effect on Interior Noise Using SEA

Closed cell foam has been used for filling vehicle pillar cavities at select locations to block road noise transmitted through pillars. In the past, most pillar foam implementations in vehicle programs were driven by subjective improvements in interior sound. In this study road test results are used to correlate a detailed CAE (Computer-Aided Engineering) model based on the statistical energy analysis method. Noise reduction characteristics of pillar with a number of foam block fillings were then studied using the CAE model. The CAE models provided means to model and understand the mechanism of noise energy flow through pillar cavities. A number of insightful conclusions were obtained as result of the study.
Technical Paper

Validation of a SEA Model for a Minivan: Use of Ideal Air- and Structure-Borne Sources

During the development of a Statistical Energy Analysis (SEA) model, the most important step leading toward higher quality and confidence is the model validation process. In this paper, three different ideal source environments are employed to validate a SEA model of a minivan; diffuse field in a reverberation room, free field in an hemi-anechoic room and single-point excitation by a shaker. The tests were intended to emphasize the air-and structure-borne paths of the model separately. During the reverberation room test, capability of the model to track the design changes was checked by perturbing the configuration of the vehicle in successive steps. Finally, the performance of the validated SEA model is demonstrated by using an operational load case.
Technical Paper

Sound Package Weight Reduction: An Analysis Through Tests and SEA Models

This paper discusses the methods of reducing weight of sound package through a new approach in sound absorption and insulation. In contrast to conventional sound package theory, a light porous material with high absorption (Ultra Light material) is used to replace a conventional porous/barrier sandwich material (classic), which results in an equivalent or better noise reduction in-vehicle with significant weight reduction. A Noise Reduction (NR) test was conducted with a box equipped with both the Ultra Light material and classic material. A SEA model of the same setup was also analyzed. Results from both the test and the analysis show that it is possible to achieve weight reduction by replacing conventional porous/barrier sandwich materials with light porous materials with high absorption.
Technical Paper

Calculating Partial Contribution Using Component Sensitivity Values: A Different Approach to Transfer Path Analysis

Transfer Path Analysis (TPA) is a widely used methodology in Noise, Vibration and Harshness (NVH) analysis of motor vehicles. Either it is used to design a vehicle from scratch or it is applied to root cause an existing NVH problem, TPA can be a useful tool. TPA analysis is closely related to the concept of partial contribution. The very basic assumption in TPA is that the summation of all partial contributions from different paths constitutes the total response (which could be either tactile or acoustic). Another popular concept in NVH analysis of vehicles is the component sensitivity. Component sensitivity is a measure of how much the response changes due to a change in one of the components of the system, i.e., the thickness of a panel or elastic rate of an engine mount. Sensitivity rates are more popular among CAE/Simulation community, simply because they are reasonably easy to calculate using mathematical models.
Technical Paper

Electric Vehicle Sound Quality

Environmental concerns as well as regulatory requirements are driving the development of alternative vehicle propulsion systems. Electric vehicles (EV's) are attractive because they emit no pollutants. In this paper, we examine the sound quality characteristics of wind and powertrain noise in electric vehicles. Sound quality is an important attribute of EV's, because the expectation is that they will be very quiet due to the absence of an internal combustion engine. As we show in this paper, the absence of engine noise is both a blessing and a curse for sound quality. For wind noise, the results show that electric and gasoline vehicles have equivalent wind noise loudness levels at all speeds. However, at lower speeds (50-60 mph), the EV is judged to have more wind noise even though the level was the same as the gasoline vehicle! The difference is that, in the EV, there is no engine noise to mask the wind noise.
Technical Paper

Process to Achieve NVH Goals: Subsystem Targets via “Digital Prototype” Simulations

A process to achieve vehicle system level NVH objectives using CAE simulation tools is discussed. Issues of modeling methodology, already covered adequately in the literature, are less emphasized so that the paper can focus on the application of a process that encompasses objective setting, design synthesis, and performance achievement using simulation predictions. A reference simulation model establishes correlation levels and modeling methods that are applied to future predictions. The new model, called a “Digital Mule”, is an early new product “design intent” simulation used to arrive at subsystem goals to meet the vehicle level NVH objectives. Subsystem goals are established at discrete noise paths where structure borne noise enters the body subsystem. The process also includes setting limits on the excitation sources, such as suspension and powertrain.
Technical Paper

Characterizing the In Vehicle Performance of Expandable Sealants Used As Acoustic Baffles

Chemically and heat reactive, expandable sealants are used as “acoustical baffles” in the automotive industry. These acoustic baffles are used to impede noise, water and dust propagation inside of structural components and body cavities. Use of these sealant materials has grown significantly as the demands to improve vehicle acoustic performance has increased. Various test methods have been developed to quantify the performance of these materials through direct comparison of material samples. These investigations use standardized testing procedures to characterize the acoustic performance of a material sample on the basis of controlled laboratory test conditions. This paper presents a step in the progression of evaluating acoustic baffle performance in the vehicle. Standard experimental techniques are used to investigate the influence of the baffles on the vehicle acoustic performance.
Technical Paper

Acoustical Selection of Class 8 Truck Floormats

Class 8 truck manufacturers use a wide variety of materials for cab floor construction. These include traditional steel and aluminum plate as well as aluminum honey-comb and balsa wood core composites. Each of these materials has unique transmission loss properties. The acoustical performance of the floor system, (cab floor, decoupler, and barrier) depends not only on the acoustical performance of the decoupler and barrier, but also on the cab floor material. This paper outlines an experimental technique for selecting an acoustical floormat system utilizing vehicle and laboratory tests that takes these factors into account.
Technical Paper

The Next Step in Acoustical Part Weight Reduction

Weight reduction with maintained part performance is a continuing trend throughout the automotive industry. Acoustical insulation parts (carpet underlay and dash insulators) are no exception. Several years ago, ICI Polyurethanes led the industry in establishing a molded density standard of 48 kg/m3. Although this is the current production standard, the technology drive is toward even lower weights. Recent technological demonstrations show that molded densities of 35-38 kg/m3 are achievable. In addition to removing weight, acoustical performance can be maintained with no deficiencies in physical characteristics.