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“Spotlight on Design” features video interviews and case study segments, focusing on the latest technology breakthroughs. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. In the episode “Composite Materials: Advanced Materials and Lightweighting” (30:20), Molded Fiber Glass Companies, known for its deep involvement in the creative development of the molded fiberglass process for the Corvette, demonstrates the manufacturing of sheet molded composite for fiberglass parts. Tanom Motors introduces the Tanom Invader, a blend between an automobile and a motorcycle made exclusively with composite materials. Finally, Euro-Composites demonstrates the manufacturing of honeycomb core material made out of aramid paper and phenolic resin used in aircraft structures.

“Spotlight on Design: Insight” features an in-depth look at the latest technology breakthroughs impacting mobility. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. When automotive and aerospace manufacturers look for a material with superior lightweight and strength characteristics, they often look no further than composite materials. In the episode “Composite Materials: New Trends in Automotive Design” (10:20), an engineer from Molded Fiber Glass Research Company demonstrates how they develop and test the properties of composite materials, and an engineer at MirTEQ Incorporated discusses designing molds for an aftermarket composite part.

Since 2006 Oak Ridge National Labs (ORNL) and the Pacific Northwest National Labs (PNNL) have conducted research of injection molded long glass fiber thermoplastic parts funded by U.S. DOE. At DOE's request, ACC's Plastics Division Automotive Team and USCAR formed a steering committee for the National Labs, whose purpose was to provide industry perspective, parts materials and guidance in processing. This ACC affiliation enabled the plastics industry to identify additional key research requirements necessary to the success of long glass fiber injection molded materials and their use in the real world. Through further cooperative agreements with Autodesk Moldflow and University of Illinois, a new process model to predict both fiber orientation distribution and fiber length distribution is now available. Mechanical property predictive tools were developed and Moldflow is integrating these models into their software.

In a variety of industries there is a growing need to manufacture high quality carbon fibre epoxy matrix composite structures at greater production rates and lower costs than has historically been the case. This has developed into a desire for the automation of the manufacture of components, and in particular the lay-up phase, with Automated Tape Laying (ATL) and Fibre Placement (AFP) the most popular choices. When used for large primary structures there are such potential gains to be had that both techniques have seen rapid implementation into manufacturing environments. But significant concerns remain and these have limited their wider adoption into secondary structure manufacturing, where manual forming of woven broadgoods is dominant. As a result the manufacture of secondary structures is generally explored for costs reduction through drape simulation and lower cost materials.

Electroimpact Automatic Fiber Placement (AFP) machines lay-up composite parts by accurately placing carbon fiber tow (strips of impregnated carbon fiber) on a mould. In order to achieve high accuracy at high speeds, the processes of feeding and cutting tows must be tuned. Historically, the tuning has been a time-consuming, manual process. This paper will present a methodology to replace manual measurements with an automated laser, improve measurement speed by an order of magnitude, improve accuracy from +/? 0.020? (manual) to +/? 0.015? (laser), and eliminate human error. Presenter Joshua Cemenska, Electroimpact Inc.

At the end of 2006, two MTorres engineers visited the plant of Airbus UK in Filton receiving a new challenge: Find a more efficient way to manufacture Carbon Fiber Spars for the new A350 program. The range of possibilities were wide: manual infusion methods (RTM, RIM, RFI...), Automatic Taping & hot forming, or the new technology proposed, Fiberplacement or AFP. Two (2) options were considered: hot forming+ATL and AFP (both using prepeg technology.) The usage of a flat lay-up + hot forming technology was used in the only Airbus program that used carbon fiber for the wing manufacturing so far, the A400M. The expected greater complexity of A350 spar created doubts on the feasibility of using the above process, while the AFP technology, consisting of laying up directly on the final shape of the spar, also raised questions of technical feasibility, apart from the economic ?business case?, in case the productivity of the cell was not big enough. A ?Spar team?

USEFUL load-carrying capacity is a measure of the comparative value of two airplanes of the same size, having identical powerplants, speed, rate of climb and other flying characteristics. It seems to be feasible to combine in the same airplane both the greatest ability to carry useful load and the least cost of construction. Blanked and pressed metal work offers substantial advantage to the extent that parts, particularly sub-assemblies, can be made directly by machine in complete units ready to set in the final assembly. The author shows and describes the methods followed by his organization in forming the members, building the frames and assembling the units of metal aircraft. Trusses are blanked and the web members pressed to ¾-circle form. Dies for long members are variable in length by being made in pieces that can be removed or inserted as desired. Flanged-tube sections are employed for truss chords.

EITHER steel or cast iron will provide a good braking surface provided the grain structure is laminated pearlite, according to the author. Such a structure can be secured in pressed steel by alloying or by case-hardening, in high-carbon steel rings welded to a stamped back and in centrifugally cast iron by careful control without alloying. Uniformity of analysis is important and control of the rate of cooling is still more important in castings. The graphite content of iron is not considered important as a lubricant. Methods of centrifugal casting and of testing are illustrated; also the form and microstructure of representative brake-drums. Discussers agree as to the microstructure needed and present additional views as to ways of securing that structure and the desirability of capacity for absorbing and dissipating heat. They believe grain size and strength more important than hardness.

CYLINDER-BLOCKS, with their hollow form and complicated arrangement of water-jackets, valve passages, pockets and bearings, are difficult to cast, and require a large quantity of cores. These have generally been baked or dry-sand cores, but the author's organization has met with success in making the more bulky cores, those for the cylinder-barrels and crankcase, in green sand. Descriptions and copious photographs and drawings are given of two methods of molding one six-cylinder block in green sand, and the possibilities of the system are indicated by illustrations of cylinders and details of cylinders that have been molded or that are suitable for molding in green sand. Cooperation between designer and foundryman is essential in realizing the economy possible with this method of molding, a large part of which results from the great saving in cost of sand.

The Chicago Service Meeting paper relates specifically to the type of garage equipment that is used to handle the motor vehicle in preparation for its repair. The devices illustrated and described are those designed to bring in disabled cars, and include wrecking cranes and supplementary axle trucks; portable cranes and jacks on casters for handling cars in a garage; presses, tire-changing equipment and wheel alignment devices; engine and axle stands; and miscellaneous minor apparatus. The different factors mentioned emphasize the great need of standardization. The thought is not to do away with a car's individuality, but to construct all parts so that cars may have efficient service to the highest degree through the agency of every serviceman.

Coining-press development is outlined and the author tells how such machinery was adapted to speed-up the production of automobile parts, such as forged arms and levers, by a squeezing process that superseded milling or spot-facing methods. The presses used are very rugged in construction and have the appearance of a plain-type punch-press, except for the knuckle that operates the ram. This knuckle is coupled to a crank by a connecting-rod or link. As the crank revolves, it straightens the knuckle. The pressure transmitted to the ram is many times greater than that which could be produced through a single-acting direct-connected crank-operated type of machine. An additional advantage of the knuckle movement is in the application of pressure at the end of the downward stroke. The position of the ram at the end of the stroke is controlled by a screw-actuated wedge.

The author limits his consideration of rear axles to that of the bevel-gear type and takes up the subject under the heads of load-carrying member, gearing, driving-shaft, brakes and materials. Several different forms of cast and pressed axle housings are briefly described. Mention is then made of the axle gearing and data given showing the end thrust for straight-tooth bevel pinions. The methods of supporting pinions and of attaching bevel gears to the differential are discussed. Forms of differentials are considered, several different conventional types being illustrated. The subject of driving shafts is briefly reviewed, as is also that of brakes and brake materials. The author concludes his paper by figures showing the tensile strength, elastic limit and elongation of the metals used in the various parts of the rear axle and also explains some oil-retaining and dust-protecting features of design.

ACTUAL production-equipment for making rubber goods by the anode process has not been installed and studied to yield accurate quantitative data, but laboratory work has been begun in Akron, Ohio, and although some of the facts learned cannot be discussed by the author at this time, enough general indications have been secured to lead to belief that widely varied and valuable applications of the process will be made. Factors that influence the commercial application of any process are enumerated and the properties of rubber that the technologist usually studies to determine its suitability for specific uses are listed. Thorough comparison of anode rubber with the milled product has not been made but confirmatory experimental evidence supports belief that the process must yield stronger and tougher material than do current methods of production. The reasons for this are explained.

AFTER giving a brief description of the nature of rubber latex and a review of investigations made in Europe of its physico-chemical properties, the author tells of experiments made in Rochester to develop a method for the electrodeposition of rubber particles. These proved that the process was possible but the problem of producing a coating containing all the ingredients requisite in a compound suitable for vulcanizing remained to be solved. The nature of the rubber particles and of rubber after coagulation of the particles is described and the method of rubber-plating as developed is explained. It is stated that the deposit can be built up almost indefinitely and at a very rapid rate; that the composition remains substantially unchanged during coating, and that the current efficiency is remarkably high.

TOOTHED and friction-gearing are said by the author to be the two distinct classes of power transmission between two shafts, and the silent chain he describes is in the toothed-gearing class according to his statement, since it has a fixed speed-ratio and causes a bearing pressure that varies almost directly with the power transmitted. It is argued that, because of its elasticity and the peculiar method of contact with the teeth of the sprocket, the silent chain constitutes a medium that absorbs shocks and variations in angular velocity, and has a bearing action similar to that of a belt. The improved silent chain is made of stamped, arch-shaped link-plates assembled in alternate succession and joined by pins that act as bearings. The spacing of the pins forms the “pitch” of the chain. When assembled, the chain can be considered a flexible gear or rack.

THE monocoque type of fuselage construction seems to promise satisfaction of the three requisites of prime importance; namely, high strength-weight ratio, “streamlined” form, and unobstructed interior, according to the author. The conventional method of building a fuselage consists, first, in the construction of a “form” of the required shape, upon which a layer of veneer is fastened. Other layers are applied, and thus a fuselage shell of two or three plies is completed. But the process is expensive and laborious, involving the handling and individual fitting of many small pieces. In the process described by the author, a wooden form of the exact shape of one half of the fuselage body, divided on a vertical plane passing through the center line, is built. This form, or pattern, is next suspended in a large box in which reinforcing bars previously have been woven, and concrete is poured in.

A TABULAR statement in which comparisons are made between acceleration and deceleration is presented by the author as proof of the need of frequent and scientific maintenance practices with regard to brakes. From the viewpoint of service, the author believes that the engineer's findings as to what constitutes the best lining for the particular brake he has designed for his particular car must be adhered to strictly. No one brake-lining will work equally well on all cars. In reconditioning used cars of any make, he has purchased the lining supplied by the manufacturer of the particular make of car when possible. Although water affects brakes equipped with molded linings, the trouble is only momentary, according to the author, because the heat quickly dries off the surface moisture. Squeaks are seldom caused by the molded lining itself, but mostly by protruding rivets, out-of-round brake-bands or brake-shoes, foreign matter on the linings, or eccentric adjustments.

IF brake-lining manufacturers would insist on holding the values of friction coefficients to 0.3 or 0.4, many of their troubles would cease, in the opinion of the author, who asserts that the main objections to high friction-coefficients are rapid wear, greater liability to cause scoring, and instability. The first results of tests on molded brake-lining materials were so superior to tests on woven material that further development of molded materials was carried on. Regardless of the type or make of molded material tested, it was found that the friction-coefficient value remained much more uniform than did that of woven material and that, without exception, the friction value and general characteristics of molded material were not changed by wear conditions. Molded material shows longer life than woven material, according to tests, and the author thinks that possibly this is because of the completeness of the saturation of the molded material.

FIRST reviewing briefly the history of molded brake-lining, the author states that the introduction of molded lining has, until recently, met with considerable opposition. After the first volume-production adoption in 1924, there were no further adoptions of the strictly molded types in production until 1927, when the trend in brake design seemed to change suddenly from the external type to the internal type of brake. The present movement toward the use of molded brake-lining was brought about through the inability of woven lining to meet the exacting demands of some of the newer types of internal brake. In the author's opinion, the molded type of lining has more nearly fulfilled the present requirement of internal brakes than has any other type. He states that at least seven different brands of molded lining are now on the market, and that three of them are in large-volume production.