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Viewing 164461 to 164490 of 190464
1974-02-01
Technical Paper
740337
J. M. Fleming, M. J. Percy
An inexpensive, flexible and convenient finite element analysis system can be implemented with limited capital and resources. A system of this nature can be a functional tool of the designer and stress analyst for the analysis of many types of mechanical components. The finite element models generated by this system can approach a high degree of complexity with a small time investment compared to the time required to do this job without the aid of the system described.
1974-02-01
Technical Paper
740338
D. Radaj, A. Zimmer, H. Geissler
The finite element method as a modern technique for the automobile engineer will become fully effective provided that all its possibilities and requirements are taken into account. As a basic prerequisite for such a development, the importance of computer analysis, experimentation and mechanical design are illustrated and expectations with regard to finite element programming systems are shown, coupled with explanations covering the verification of the finite element method and its qualified use as an absolutely necessary prerequisite for success. Systems used or taken into consideration by Daimler-Benz are critically reviewed and some successful computer projects conducted are presented.
1974-02-01
Technical Paper
740331
Richard N. Karnes, James D. Sebastian, James L. Tocher, David W. Twigg
This paper describes the conversion of a crash analysis program from its original batch program form with awkward input to an efficient, user-oriented interactive tool. The program simulates a vehicle occupant with a two dimensional, seven link mathematical model restrained by a seat belt and shoulder harness. A nonlinear finite element capability was added to enable modeling of a seat which would interact realistically with the occupant. A new differential equation solver was developed which achieved a sixty per cent reduction in the computer time required for the transient response analysis. The modified program incorporates user aids such as free-field data input and an on-line data edit capability. Output was reformatted to provide user-selected time history and occupant configuration plots as well as readable printout.
1974-02-01
Technical Paper
740332
Ali Youssef, Leslie G. Jaeger
A full nonlinear analysis, geometric as well as constitutive, of cracked plates in plane stress and strain is given. The theory is formulated in a Lagrangian frame of reference. The Newton-Rahpson method is used to solve for generalized displacements in the resulting nonlinear equilibrium equations. An elastic-perfectly plastic behavior is assumed. An example of a plate containing a sharp crack and subjected to tensile load is solved using a developed finite element computer program. The analysis reveals the extent to which linear elastic-plastic approximation can be used with confidence. The inclusion of changes of large geometry results in higher and more intense strains directly ahead of the crack tip. Also a limited value of stress is achieved in the near crack tip zone. In general, the full nonlinear analysis presents a better representation of ductile fracture mechanisms than does linear elastic-plastic analysis.
1974-02-01
Technical Paper
740334
T. Belytschko, R. E. Welch, R. W. Bruce
A method is presented for the transient analysis of structures including nonlinearities in material behavior and geometry. A system of rigid convected (or corotational) coordinates that rotate and translate with each element is used to simplify the governing equations so that an efficient computer code could be developed. For purposes of applying the method to problems with moderately large relative rotations within an element, this paper introduces additional terms to account for these variations of the rotation. Results are presented for a variety of elastic and elastic-plastic problems.
1974-02-01
Technical Paper
740333
Sing C. Tang, Robert C. Petrof
This paper is concerned with the development of a finite element method for the elasto-plastic analysis of a gas turbine wheel under severe thermal and mechanical loads. A computer program based upon this development has been written and checked by running sample problems for which the solutions exist in the literature. The output of the computer program gives the transient displacements and stresses for a specified set of discrete points in the structure. As an illustration of an actual application, one power turbine wheel has been analyzed by using the developed method and running the checked computer program. The method developed in this paper should serve as a useful tool in turbine wheel design and should result in improved wheel designs and extended engine durability.
1974-02-01
Technical Paper
740464
Dennis Stein
The purpose of this paper is to present the analytical, developmental, and test efforts used to achieve an integrated system responsive to the U.S. Army's heavy-lift helicopter (HLH) needs. A comprehensive discussion of various approaches which were examined with particular emphasis on elements unique to this aircraft are presented. The methodology used in interfacing various components in determining the final design configuration is also presented.
1974-02-01
Technical Paper
740458
F. Klujber, J. V. O'Keefe
Recent developments in sonic inlet technology are presented with particular emphasis on STOL propulsion systems. Inlet noise reduction requirements are discussed for an augmentor wing and an upper surface blowing type of propulsion system. The current state of the art is discussed with respect to performance and noise potential of different sonic inlet concepts. Acoustic and aerodynamic performance comparison is presented for several inlet configurations based on experimental results.
1974-02-01
Technical Paper
740466
E. A. Green
The secondary power systems on the L-1011, that is, the hydraulic, electrical power, pneumatic systems and their components, were all designed with the total aircraft system operation integrated into each subsystem as a firm design requirement. In some cases where supplier components had a major effect on systems design, the supplier was given responsibility to integrate some or all of a secondary power system. A detailed analysis of aircraft operation, including the required redundancy, was developed as a portion of each system design. Then the interaction of the systems was considered in determining the final design configuration. This paper deals with the design philosophy used in each of these power systems, and their description and operation. It draws conclusions concerning the improvements in system or design approach which may be proposed for future designs.
1974-02-01
Technical Paper
740467
W. L. Jones, L. J. Heidelberg
A summary is presented of an acoustic test program for investigating engine noise suppression and jet/flap interaction noise associated with an EBF STOL powered lift system. A highly suppressed TF-34 engine and EBF wing were used in the investigation. The engine was suppressed 21 PndB to a level of 94 PndB. An UTW powered lift system was tested with conventional, mixer, and decayer-type nozzles. The configuration with velocity decayer nozzle and acoustically treated shroud had the lowest noise (98 PndB). An OTW configuration with non-decayer nozzle was about 10 dB quieter than the corresponding UTW system. UTW and OTW noise data are compared with scale model correlations.
1974-02-01
Technical Paper
740468
Robert G. Dorsch
The Lewis Research Center cold-flow model externally blown flap (EBF) noise research test program is summarized. Both engine under-the-wing and over-the-wing EBF wing section configurations were studied. Ten large scale and nineteen small scale EBF models were tested. A limited number of forward airspeed effect and flap noise suppression tests were also run. The key results and conclusions drawn from the flap noise tests are summarized and discussed.
1974-02-01
Technical Paper
740470
Joseph L. Johnson, Arthur E. Phelps
This paper summarizes the results of recent wind-tunnel investigations conducted to provide fundamental aerodynamic information on the upper-surface blown jet-flap concept incorporating high-bypass-ratio turbofan engines. The results of the investigations have shown the concept to have aerodynamic performance generally comparable to that of other externally blown high-lift systems. This paper will cover some of the more critical problem areas associated with this concept and will discuss solutions which have been found for these problems.
1974-02-01
Technical Paper
740469
Howard Skavdahl, Timothy Wang, William J. Hirt
A discussion of wing-nozzle configuration development for the application of upper surface blowing to a STOL airplane is presented. The technical challenge is to achieve an integrated system which provides the desired performance for the low speed design conditions and also results in efficient operation during cruise. The resulting configuration is a complete integration of the propulsion system and airplane aerodynamics to achieve efficient operation at all regimes. This paper examines the major design parameters to be considered, describes a number of the configurations tested, and presents static and wind tunnel test results for these configurations. Concluding remarks are made relative to USB nozzle development.
1974-02-01
Technical Paper
740472
Martin Lieberman, Alan Beerbower, Ronald H. Kroop
The disposal of waste lubricants and fuels at U.S. Air Force and Navy facilities is discussed in this paper. The waste products covered include: synthetic turbine oil, aviation piston engine oil, hydraulic fluids, and contaminated JP-4 and JP-5. Technical feasibility and the economics of various disposal alternatives, including use as a fuel, rerefining, and recycling, as well as entrepreneurial outlets are presented. Waste lubricants and fuels handling, classification, and storage are also discussed in connection with the disposal problem.
1974-02-01
Technical Paper
740471
M. K. Bowden, J. H. Renshaw, H. S. Sweet
In a discussion of STOL vehicles with conventional high-lift devices, the need for efficient power-augmented lift systems is presented and the implications of quiet operation are noted. The underlying philosophy of a promising hybrid lift system with major interactions between aerodynamic, thermodynamic, acoustic, and configuration design technologies is derived. The technique by which engine and airframe-related characteristics for this application may be matched in an optimum manner is described and illustrated by describing the features of a particular short-haul commercial STOL vehicle.
1974-02-01
Technical Paper
740473
T. E. Russell, R. E. Mattes
An evaluation of the influence of two classes of fuels and four types of lubricants on supersonic military interceptor aircraft performance at the airframe subsystem and engine component level is presented. Engine cycles representative of anticipated technology levels in the 1980 time period are analyzed to determine interceptor performance as a function of fuel and lubricant properties and temperature limitations. The relative allotment of available fuel heat sink between engine and airframe is also investigated to determine the primary factors affected by fuel interface temperature and to provide meaningful design guidance for future system applications. The results indicate that with an integrated systems approach to the management of the aircraft and engine system heat loads, JP type fuels and type 2 (MIL-L-27502) lubricants will meet the minimum requirements for advanced military systems.
1974-02-01
Technical Paper
740477
S. B. PORITZKY
Airport capacity at major airports is less now than it was only a year ago. The prospect of ATC technology improvements providing major capacity increases are much smaller than anticipated. The bigger payoff must come from a truly integrated total airport design, along with enough runways, adequate airport access, and in the long term airplanes which better fit high density airports. The paper outlines problems which are affecting airport capacity, and assesses the problems and prospects in achieving major improvements in airport capacity and reduction of delay. Many elements must work synergistically and must be drawn more closely together if there is to be a cost-effective, high-capacity airport system.
1974-02-01
Technical Paper
740474
Charles L. Blake
In order to formulate policy for the orderly development and use of the nation's navigable air space, federal agencies such as the FAA and the Department of Transportation have launched several programs to determine aviation requirements for the next 10 years. This paper outlines their conclusions concerning airborne activities such as flow control, approach and departure control, wake vortex problems, and operating procedures as well as airport capacity and ground operations. The impact of the FAA's Research and Development Program and the implications of the current fuel shortage and economic situation are also discussed.
1974-02-01
Technical Paper
740475
Armen DerHohannesian
In a comparatively short time, air transportation has established itself as by far the dominant mode of intercity travel by common carrier and it will continue to be in the foreseeable future. However, the ability to continue to provide the safest and most convenient method of intercity transportation is in jeopardy if airport facilities are not available in time to accommodate adequately the levels of traffic which the demands for air service generate. This paper, although recognizing the importance of all airport system components, assesses the airfield capacity problem of today and the future and describes various influences that affect the airport operator's attempts to improve capacity.
1974-02-01
Technical Paper
740480
M.J. Wendl, G.G. Grose, J.L. Porter, V.R. Pruitt
Analytical studies indicate substantial aircraft performance benefits can result from proper application of energy management principles, and that conceptual approaches involving close coupling of aerodynamic, propulsion, and control technical elements are required to achieve these benefits. Analytic tools used in these studies include a modified Rutowski technique for simultaneously optimizing throttle position and flight path. Pilot-in-the-loop simulation results are presented and the use of advanced pilot displays utilizing energy management techniques are described. Factors affecting the implementation of Flight/Propulsion Control Integration (FPCI) techniques for energy management are considered. Elements of fly-by-wire control augmentation systems, electronic engine controls, advanced pilot displays, and automatically controlled inlet and nozzle systems in future aircraft designs are discussed.
1974-02-01
Technical Paper
740478
William G. Schweikhard, Donald T. Berry
Interactions between propulsion systems and flight controls have emerged as a major control problem on supersonic cruise aircraft. This paper describes the nature and causes of these interactions and the approaches to predicting and solving the problem. Integration of propulsion and flight control systems appears to be the most promising solution if the interaction effects can be adequately predicted early in the vehicle design. Significant performance, stability, and control improvements may be realized from a cooperative control system.
1974-02-01
Technical Paper
740440
J. Fructus, C. Eline
The decree of 11 April 1972 has introduced stringent limitation on bystander noise of industrial equipment in France. The maximum permissible level of 80 dB(A) at 7 metres constitutes today's lowest limit imposed by any legislation. The specificity of the decree is analyzed and an attempt has been made to review the situation from a manufacturer's standpoint. Various difficulties encountered by the manufacturers have resulted in extensive development programs and longer lead time to produce the modified equipment. Thus, the effective date of 2 May 1973 initially adopted in the decree could not be met by most manufacturers, and general or individual deviations have been accepted by the Ministry of Protection of Nature and Environment. The general deviation of 21 December 1973 indicates ultimate dates of availability accepted for each machine. The noise reduction on four wheel drive loaders is presented as an actual example of application of the decree.
1974-02-01
Technical Paper
740441
John J. Breslin, Richard J. Anderson
1974-02-01
Technical Paper
740442
Thomas F. Sheehan
This paper discusses the legal responsibilities of business professionals in terms of civil and criminal liabilities. Individuals are now facing lawsuits for violations performed within the corporation, and the paper gives details of several such cases. The paper concludes that liability insurance for directors and officers of corporations is necessary to protect such individuals.
1974-02-01
Technical Paper
740443
Gary A. Roberts
A new concept has been developed for data acquisition from equipment operating in the field. This technique, called statistical monitoring, offers unique potential for improving product reliability and performing system diagnostics. This paper presents the principles underlying the statistical monitoring concept, the techniques for applying the data to reliability and diagnostic problems, and a discussion of the program for incorporating the method in a general reliability improvement program.
1974-02-01
Technical Paper
740444
P. R. Stephens
The Service Department influences product design continually by evaluating product reliability, acceptability, and serviceability from a customer's point of view. Design sections require precise technical information on all three items. This paper describes several Service Department systems utilized to provide this information in a consistent and orderly fashion.
1974-02-01
Technical Paper
740445
Gilbert D. Herr
Engineering design of industrial and construction equipment can heavily influence the saleability of the product and the attitude of the dealer who sells and services it. Engineers should design from initial concept for: ease of operation, maintenance, and repair; safe operation; and esthetic appeal. We take for granted that the machine will incorporate reliability and productivity in its basic design.
1974-02-01
Technical Paper
740447
John C. Tucker
Trade deficits in recent years led the U.S. government to take a hard look at its international trade policy. The result was a dollar devaluation and other government incentives to industry to increase exports. These increased exports mean more problems to corporations already selling overseas and new problems to corporations who have not previously marketed overseas. This paper will examine some of the problems involved in overseas marketing as opposed to domestic marketing.
1974-02-01
Technical Paper
740446
C. C. Cushman, P. T. Quinlan
Dealer development is a composite of policies and procedures blended with guidance and counsel for the express purpose of developing one of the manufacturer's most important assets-his retail dealer organization. By properly utilizing the combination above, a manufacturer-supplier's objective should be to develop the dealer organization to the point where they maximize sales potential and profitability. We will consider the subject of dealer development from a manufacturer's point of view from three aspects: 1. What is a dealer development program? 2. When is the appropriate time for a manufacturer-supplier to consider a dealer development program? 3. Basic ingredients and implementation of a dealer development program.
1974-02-01
Technical Paper
740448
C. E. Sanders
Contractors continue to purchase manufacturers' machines which are designed for an intended operation, although such machines cause operators, mechanics, and owners undue downtime and increased operation and maintenance cost. Some of the recurring problems identified by contractors' personnel are included in this presentation.

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