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Technical Paper

Integration and Validation of Sheet Metal Forming Simulation Computer Programs Into the Design Process

1996-04-01
91A121
In order to improve the design of drawn parts and to reduce the number of trial and error tests, Renault has undertaken the development and the validation of various finite element procedures and codes. This paper describes the function of each software and its level of integration into the design process. One of them is already an operational tool used be planners whilst the others are still in the validation phase. Selected examples show typical applications of the computer programs on automotive parts.
Technical Paper

Multifunctional Glasses for Automotive

1996-04-01
91A109
The windows of a vehicle have to satisfy the following driver and passenger needs concerning visibility and climate perception both related to active safety: transparency, reluctance, dazzling, glare and diffused light (scattering). All functions are related to visibility and so to the optics of glazing, solar control, deicing, defogging, demisting. The task of material science is to find the multifunctional glasses solving simultaneously problems of visibility, safety and comfort. Particular kind of glasses, colored, wired, coated, electrochromic, liquid crystal, photochromic can be already considered solutions which can operate passively or actively. The example of passive solar control and active heatable coated glasses is shown as a possible practical multifunctional glass very soon.
Technical Paper

Antiwear Properties and Applications of Thin Hard Coatings

1996-04-01
91A106
Different techniques, like PVD, CVD, ion implantation, are increasingly used to produce thin film layers of ceramic compounds to modify the surface properties of metals, carbides, ceramics or polymeric components for specialized conditions or in severe conditions of use. Carbides, nitrides, oxides, etc. have been deposited on the most varied supports to solve problems of high temperature, erosion, corrosion, diffusion and conductivity or electrical resistance. The fields of thin hard coating applications are: tools, dies, punches, mechanical components (for antiwear deposits), structures (for anticorrosion), optics (reflecting or absorbing layers) and microelectronics. In this paper we will present the principal characteristics of different thin hard coating layers and processes, and the principal applications in the anti-wear field.
Technical Paper

The Prediction of Shrinkage and Warpage in Plastics Injection Molded Auto Parts

1996-04-01
91A088
The article emphasizes the effect of flow on dimensional stability, mechanical properties and surface finish, and the close coupling of dimensional stability and mechanical properties. Warpage is the result of the balance between the structural stiffness of the part and the stress pattern resulting in variation in shrinkage due to area shrinkage, orientation, and thermal effects. The practical solution to warpage depends on the use of software to isolate the basic causes of warping which then leads to a logical solution procedure.
Technical Paper

A Driving Simulator Using Microprocessors

1988-03-01
871156
An inexpensive driving simulation system with sufficient fidelity has been developed. The system produces motion cues of four degrees of freedom, visual and auditory cues, and control feel on the steering wheel. This paper describes the features of this newly developed system and gives examples that demonstrate its effectiveness. The motion cues provided in this system are yaw, heave, and lateral and fore/aft accelerations. The lateral and fore/aft accelerations are simulated by tilting the simulator compartment. A computer-processed road image is given through a CRT monitor. The restoring torque of the steering wheel is produced by an electrical servosystem via a coil spring. Cruising sound is given in order to improve speed perception. Since the system uses digital computers, the vehicle characteristics are altered easily by merely rewriting the software. This enables us to simulate special vehicle dynamics such as front & rear wheel steering.
Technical Paper

Use of Statistical Energy Analysis Method to Predict Sound Transmission Loss of Sound Barrier Assemblies

1999-05-17
1999-01-1707
Statistical Energy Analysis (SEA) method is used to predict Sound Transmission Loss (STL) of sound barrier assemblies (SBA) commonly used in automotive dashmat design. Tests are performed for dashmat plaques with and without design features, and SEA equations have been used for predicting transmission loss with acceptable accuracy below the interception (cavity resonance) frequency. For frequency range higher than interception point, the SEA software used overestimates STL. For dashmat tests with design features, test results and SEA predictions are generally agreeable.
Technical Paper

A New Wavelet Technique for Transient Sound Visualization and Application to Automotive Door Closing Events

1999-05-17
1999-01-1682
Transient automotive sounds often possess a complex internal structure resulting from one or more impacts combined with mechanical and acoustic cavity resonances. This structure can be revealed by a new technique for obtaining translation-invariant scalograms from orthogonal discrete wavelet transforms. These scalograms are particularly well suited to the visualization of complex sound transients which span a wide dynamic range in time (ms to s) and frequency (∼100Hz to ∼10kHz). As examples, scalograms and spectrograms of door latch closing events from a variety of automotive platforms are discussed and compared in light of the subjective rankings of the sounds.
Technical Paper

Design and Implementation of a Damping Material Measurement / Design System

1999-05-17
1999-01-1675
A hardware / software package is presented that is used to determine the dynamic mechanical properties of viscoelastic materials as a function of temperature and frequency. The material properties can then be used to aid in the design of surface damping treatments for various engineering structures.
Technical Paper

Noise Analysis of Automotive Alternators

1999-05-17
1999-01-1712
An extensive experimental study of noise generating mechanisms of two production models of automotive alternators is presented. It was established that aerodynamic noise (generated by cooling fans) is dominating at high speeds (above 3,000 rpm), while electromagnetic noise is the most intensive at low rpm. Two directions of noise reduction are proposed and validated: reduction of noise levels generated by alternators to be achieved by using axial flow fans for cooling instead of presently used bladed discs, and radical reduction of operating speed of alternators by using variable transmission ratio accessory drives.
Technical Paper

Soft Control – Utilizing Existing I/O

1999-05-10
1999-01-1623
The Timken Company's Faircrest Steel Plant has numerous automated control systems. The Raw Material Handling System and a grinder application on the Billet Conditioning system needed upgrading; however, to control costs the upgrades had to use the existing I/O. The overall functionality of these two systems is vastly different. Soft control packages proved capable of interfacing with the existing I/O, satisfied the functional needs of the systems, and enhanced the overall functionality of the systems.
Technical Paper

Human Centered Manufacturing: a Necessity for Enhancing Productivity and Competitiveness

1999-04-20
1999-01-1605
This paper argues in favor of a human-centered (anthropocentric) approach to modern manufacturing. The bases for these arguments are: (a) worker deskilling and creativity issues, (b) economics, and (c) unresolved problems in automation, such as software reliance and costs. Detailed arguments are avoided owing to space limitations. Finally, some issues confronting human-centered manufacturing are raised.
Technical Paper

Design of Manufacturing Systems to Support Volume Flexibility

1999-05-10
1999-01-1621
This paper presents an Axiomatic Design framework for manufacturing system design and illustrates how lean cellular manufacturing can achieve volume flexibility. Axiomatic Design creates a design framework by mapping the functional requirements of a system to specific design parameters. Volume flexibility is often neglected as a requirement of manufacturing systems. Very few industries are fortunate enough to experience stable or predictable product demand. In reality, demand is often volatile and uncertain. It is important that manufacturing system designers are aware of manufacturing system types which can accommodate volume flexibility and follow a structured design methodology that assures that all requirements are met by the system.
Technical Paper

Experimental Investigation of Ice Adhesion

1999-04-20
1999-01-1584
An experimental study was conducted to investigate ice-adhesion on clean and coated aluminum surfaces. A test apparatus using the parallel plate linear shear technique was designed along with a data acquisition system for conducting the tests and recording the experimental data. A low pulling rate was applied to specially prepared test specimens for measuring the strength of ice adhesion for a range of test conditions. The effects of surface roughness, surface contamination, and water impurity on ice adhesion were investigated. In addition, tests were conducted to evaluate the effectiveness of a low ice-adhesion coating applied to aluminum test specimens. The results obtained showed that the bond between ice and metal was considerably lower for tap water than for distilled water. For the clean and coated aluminum surfaces the strength of ice adhesion varied with specimen roughness. However, no clear trend was established between ice adhesion strength and surface roughness.
Technical Paper

Detection of Icing and Related Loss of Control Effectiveness in Regional and Corporate Aircraft

1999-04-20
1999-01-1583
This paper presents a method of detecting aircraft icing by monitoring its effects on aircraft dynamics. This paper shows that uncontrolled icing on control surfaces directly influences control effectiveness. Using data from onboard attitude and navigation sensors via highly computationally efficient algorithms, the control effectiveness is estimated, thereby detecting icing. Using actual flight test data from NASA Lewis Research Center, this paper demonstrates the ability of this method to detect the loss of elevator effectiveness that occurs with uncontrolled horizontal stabilizer icing that could result from a failed deicing boot. The method is generally applicable to loss of control effectiveness due to icing. Icing affects the aerodynamic performance of aircraft by contaminating the aerodynamic surfaces. Without anti-icing equipment icing, if sufficiently severe, can relatively quickly lead to a situation in which controllable flight is impossible.
Technical Paper

Considerations About Chaotic Dynamics of Exhaust Tube and its Design Optimization in Respect to its Dynamic Properties

1999-05-17
1999-01-1657
Vibration of an exhaust tube with a non-linear fixing construction is analyzed. Numerical and laser holography investigation methods are used for the determination of vibration processes happening nearby the cylinder fixing areas. Obviously, the analyzed non-linear system can produce complex reactions even to harmonic excitations. The knowledge about such zones of “wrong” dynamic behavior may help to eliminate and reduce higher noise levels and extend the lifetime of the construction.
Technical Paper

Characterisation of the Injection-Combustion Process in a D.I. Diesel Engine Running with Rape Oil Methyl Ester

1999-05-03
1999-01-1497
The objective of the work presented here is to evaluate the potential of rape oil methyl ester (RME) to improve the combustion process in a high-speed direct injection (HSDI) Diesel engine equipped with high-pressure common-rail injection system. The study, based on the comparison of three different fuels (standard gas-oil, RME and 30% RME/gas-oil mixture), takes into account the main aspects that control Diesel combustion, from the injection rate characteristics to the spray behaviour characterised using an optical pressurised chamber. This global study of the whole injection-combustion process allows identifying some causes of the decrease in pollutant emissions observed when the engine operates with RME.
Technical Paper

Neural Network-Based Diesel Engine Emissions Prediction Using In-Cylinder Combustion Pressure

1999-05-03
1999-01-1532
This paper explores the feasibility of using in-cylinder pressure-based variables to predict gaseous exhaust emissions levels from a Navistar T444 direct injection diesel engine through the use of neural networks. The networks were trained using in-cylinder pressure derived variables generated at steady state conditions over a wide speed and load test matrix. The networks were then validated on previously “unseen” real-time data obtained from the Federal Test Procedure cycle through the use of a high speed digital signal processor data acquisition system. Once fully trained, the DSP-based system developed in this work allows the real-time prediction of NOX and CO2 emissions from this engine on a cycle-by-cycle basis without requiring emissions measurement.
Technical Paper

Fuel Quality Control by Mid Infrared Spectroscopy

1999-05-03
1999-01-1546
Gasolines and diesel fuels of wide source were analyzed with the aim to predict the quality through the mid infrared spectroscopy and the algorithms PCA-PCR and PLS. The results revealed that octane number, cetane number, MTBE, benzene, aromatics and specific gravity could be predicted with good reliability. The other relevant fuel physical-chemical characteristics were beyond the precision of the standard test methods.
Technical Paper

Heating Aircraft Reciprocating Engines

1999-04-20
1999-01-1568
Aircraft engines need preheating to be able to start without damage in cold weather. It is possible to do this efficiently by placing a small amount of heat in the proper places. An installed electric system is very convenient and easy to use. A good design will be light weight and energy efficient. Corrosion in engines that operate in cold weather can be reduced or eliminated by the right preheater design and the proper operation of the engine. Some designs of preheater systems aggravate other problems. A certain amount of caution is needed in selecting the system. The unit should be specifically matched to the aircraft and engine.
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