In order to reduce the volume of waste in general and of shredder waste from the disposal of scrap cars, the German Federal Government has prepared a draft regulation, which will be implemented unless the automotive industry and the distributors of imported cars take action on their own to achieve these objectives. The regulation provides that the car manufacturers are fully responsible for the environmentally controlled disposal of scrap cars. The return of scrap cars to the work industry must be free of change for the last owner. A nation-wide network for the return of scrap cars must be implemented by end of 1993. To reduce the amount of shredder waste the automotive industry is expected to practice recycling on non-metallic materials. Facilities required for thermal treatment of residues, which cannot be recycled, are to be installed on account of the originator, i.e. the automotive industry.
As one of the major materials suppliers to the automotive industry, Du Pont is playing an active role in helping that industry to provide solutions for effectively managing automotive waste. This is both good corporate environmentalism and sound business sense. Rightly, our partners in the industry-the car manufacturers and the components suppliers-expect us to work with them on tackling this issue. We are prepared to provide an active contribution. And, as I shall demonstrate, we are-all of us-making a vigorous effort in this area.
The main use of FRC in automobiles, with the exception of a few specialized low volume vehicles, has been until now in semistructural parts. One of the most promising process in development today, that may play major role in future structural composite fabrication, is based on SRIM technology. The rapid and extensive introduction of this process goes also through the development of deeper theoretical knowledge of the process and the development of computer simulation to aid mold design and choice of proper processing parameters. To contribute SRIM advancement, a preliminary model has been developed for viscosity changes, extent of the reaction and temperature rises, associated with the mold filling stage, as well as a simple software to evaluate the pressure drop through different combinations of reinforcements.
Mold designers and foundrymen spend a lot of time in developing molds without knowing exactly the phenomena which take place inside. Simulor, which has been used in an industrial environment for two years, offers the solution to make foundrymen understand what happens during the filling of the mold and the solidification of the part. Based on navier-stokes and heat transfer equations, simulor provides speed distribution and metal front evolution in the cavity and thermal map in the mold and the part. Some examples with different metals (cast iron, aluminum alloy) cast with various processes (sand or die casting, low pressure or gravity casting) will be given. This new tool will given foundrymen the opportunity to test the mold before having it machined and will also allow reduction in development delays.
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.
Indirect squeeze casting technology is one of the most attractive fabrication techniques of near net shape components constituted by aluminum matrix composite (AMC) materials. AMCs reinforced with both continuous and discontinuous ceramic elements have been mainly produced by infiltration of porous preforms. Nevertheless, a further promising production route offered by this technique is given by the possibility to employ ingots of pre-reinforced aluminum alloys containing ceramic particles (silicon carbide or alumina); ingots are remelted and, under suitable operative conditions, high quality composite castings of simple and complex shape are produced by squeeze casting. The present paper describes the results of an extensive experimental work carried out by Alures-Centro Tecnico Porcessi on a pilot plant scale employing a vertical squeeze casting machine with a clamping force of 315 tons.
In this paper the socio-economic and technical problems of the handling of car wrecks are discussed. The recovery of metals as a goal for shredder operations will increasingly be supplemented with the recovery of other materials such as polymers. In order to deal economically and technically with polymer materials, it is necessary to know in advance which type of wreck handling will be used. Also optimization of shredder operations allow less freedom to incorporate a variety of materials when compared with selective dismantling or disassemble of cars. It is argued that various technical solutions have to be accompanied by increased cooperation along the firms that are connected to the handling of car wrecks. Cooperation between the scrap context and designers is essential, in order to optimize dismantling practices according to criteria of environmentally preferred solutions.
Compression molding of thermoplastic sheets, consolidated or non- consolidated, reinforced with glass fibers (GMT, GRT) is applied as an economic production process in the automotive industry. The aim of this work is to evaluate how the physical and mechanical strength characteristics depend on the presence or absence of ribs and how component performance may be changed by modifying the molding parameters, altering the content and orientation of the reinforcement fibers in the ribbed areas. For this purpose, two statistical designs will be considered, the first carried out on a box type component without ribs, the second on the same component with a set of internal ribs. Two different materials with a PP matrix will be tested, a GMT reinforced with continuous random glass fibers and a 12 mm random glass fibers composite.
The purely theoretical evaluation of critical compression loads seems complex and not very reliable in the case of honeycomb panels, on account of the numerous parameters in play and their complex interrelationships. This report provides the designer with a fast tool for preliminary calculations, consisting of a finite-element mathematical model with elastic-linear code (which can be processed using a PC), which makes it possible to obtain information very closely resembling the real situation.
The pending changes in European law enabling the use of plastic lenses on vehicle headlamps provide an opportunity for further advancement of vehicle styling, lighting performance and aerodynamic efficiency. Plastic lenses can also provide a useful weight saving and contribute to energy savings during the lifetime of the vehicle. This paper discusses the current requirements, technologies and solutions for plastic lenses, and indicates the way this advance can impact on the evolution of lighting products.
Semi-liquid forming process, applied to pressure die-casting, permits to obtain low cost components with high qualitative characteristics and adequate mechanical performances. The technology is based on the employment of material with globular microstructure (flow-cast alloys) obtained subjecting a metal alloy at the time of solidification to an elevated shear rate. Such microstructure permits the accomplishment of conventional forming processes at temperatures in solidification range. The particular fluid-dynamic properties of the semi-liquid slurry and the lower injection temperature allow to obtain casting with improved soundness, without need of impregnation, and to extend die life. The present work describes the Weber (Magneti Marelli) activity of the process industrialization and some applications for the manufacture of automotive components.
The paper review some recent efforts, made by the aluminum industry, towards the development of new advanced alloys for aerospace applications; unconventional production technologies and MMC occupy an outstanding position in this context. Raid solidification processes are currently used for obtaining advanced alloys and, among them, the powder metallurgy route is one of the most commonly applied, since it has reached a considerable level of maturity. Experimental results of PM materials are shown and discussed in order to appreciate the potentialities of this class of materials and some recent further progress is shown: the spray deposition approach (osprey process). After having described the main features of the osprey process, some results obtained at the Department of Aerospace Engineering of Pisa about the development of high strength Al-alloy and MMC obtained by means of the osprey process are shown.
The replacement with plastic of an important component, formerly in steel, in the timing drive of a heavily duty diesel engine has been studied and realized. The substituted part is the toothed coupling connecting the injection pump to the timing drive. Torque that stresses the coupling has been measured with laboratory tests. The tooth stresses have been calculated with FEM analysis. Finally, fatigue tests have been carried out directly on the engine at different loadings. The test results are consistent with the predicted behavior of this component.
This paper discusses the difficulties associated with imposing recycling imperatives upon advanced materials development by examining the case of automotive materials substitution and its impacts upon the recyclability of the automobile. Parallels are drawn between today's issues, which focus upon the recyclability of the increasing polymeric fraction in automobile shredder fluff, and the junked automobile problem of the 1960's, when the problem of abandoned automobiles became a part of the environmental and legislative agenda in the US and overseas. In the 1960's, both the source and the resolution of the junk automobile problem arose through a confluence of technological and economic factors, rather than through any set of regulatory influences. The rise of electric arc furnace steelmaking and the development of the automobile shredder were sufficient to virtually eliminate the problem - so much so that today's problems are incorrectly viewed as novelties.
A data bank developed to give a concrete help to the designer concerned with fatigue-prone structures made of composite materials is described. The data bank not only collects the available results of fatigue tests on these materials, but also makes easy their statistical analysis and comparison for design purposes. It is then believed to constitute also an useful research instrument for the development of design rules for well defined classes of composite materials.
The paper summarizes the results of an experimental and numerical study performed on the rear door of a car of large production. It was carried out with a DMC ("dough molding compound") plastic material with short glass fibers. This technology makes strong the link between the production process and the mechanical properties of the component. Such properties really vary according to the fibers orientation, the distance from the injection points and the geometrical complexity of the different regions of the molded component. In some regions the fibers orientation is well defined, in others the orientation can be expressed only in average tendency terms, with a large scatter band. It is natural to think that the material modifies its behavior from region to region, showing marked orthotropic properties or, on the contrary, a compensation isotropic trend.
A procedure adopted to verify and update the finite elements model of an electric powered car-body manufactured from composite materials is described. Experimental results, obtained from modal testing of the prototype, are used in order to identify and correct discrepancies in the FE model. The availability of a highly reliable FE model allows to simulate structural modifications by computer, optimizing the use of composites and reducing in the same time at minimum prototypes construction. The approach followed suggests a possible remarkable reduction in product development costs and duration. The work has been performed within a larger program for the development of thermoplastic composite materials, with particular attention to transportation market.