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Welding for aerospace applications

Welding for aerospace applications November 1968 5 TH E MONTHLY JOURNAL OF AERONAUTICAL ENGINEERING HE use of welding in the aircraft industry has in the past been must be found. Welding might be one solution, but automatic riveting restricted, in general, to secondary structures owing to the lack of would no doubt provide serious competition to welding. The inspection of fully weldable aluminium alloys that had a strength after welding welding had always been difficult to say the least, and this single factor had comparable with that of the normal aluminium alloys used in aircraft detracted from its use. structures. The recent symposium on welding in the aerospace industry The materials we were moving towards in the struggle for a better sponsored by the Society of British Aerospace Companies has been of strength/weight ratio appeared to offer better weldability than at first great importance in showing that with the arrival of new materials and seemed probable. These new materials offering weight advantages had been techniques interest in welding as a major production tool is rapidly very much to the fore in the past four or five years, but the manufacturing growing, and that we are on the threshold of a very significant advance in capabilities had been somewhat secondary. The manipulation of these new this field. metals has however been developed satisfactorily as far as forming and The S.B.A.C., whose Fabricating Processes Panel of the S.B.A.C. machining are concerned. The question of welding had of course been Production Committee had originated the symposium, must have been given attention by the welding research engineers and welding of these new materials may now be able to offer some palliative to the eternal problem gratified by the response and the attendance. Rarely has the lecture of weight to the designer. theatre at the Royal Aeronautical Society been seen with such a high load factor as during the two day conference. The question of distortion and built-in stresses had also in the past been The opening address was given by Mr R. A. Courtman, Executive a major deterrent to the use of welding as an assembly process, but with Director - Manufacturing of Hawker Siddeley Aviation, Kingston. He the application of electron beam and other processes which localised the said that welding had been more readily accepted in the aero engine field heating of the workpiece, some of these problems could be overcome. However, some answers to the high tooling costs involved in these welding than in the airframe field, but he thought that we were on the point of processes still had to be found. obtaining acceptance of welding in the airframe and other fields in aero­ space. Mr Courtman believed that many of the recent advances in the manu­ In the past five years, Mr Courtman continued, the attention of produc­ facturing field had been entirely in the hands of the production engineer, numerical control in the machine shops, automatic pipe-bending, dualform tion engineers had been focused on other perhaps more fashionable pressing etc., but in the case of welding there was a very different climate. processes, in particular on numerically controlled machine tools which had stepped up metal removal to very high rates. Metal removal by mechanical Here the process still had to be sold to the designer, the chief inspector, as means had always been an expensive business and although numerical well as the capital expenditure controller. control had speeded up the process, the fundamental costs were still there. The new techniques in welding, and the very much improved control of A vast amount of expensive raw material, in some cases as much as 90 per the various control processes had stimulated the production and design cent, was reduced to swarf, which was virtually scrap material with a low engineers' interest, he concluded, and welding was now being presented as value. a viable commercial proposition with the reliability and the integrity necessary to warrant its wider use in airframe, hovercraft and similar Mr Courtman thought that the acceptance of numerical control in the manufacture. machine shops had stimulated manufacturing research in other fields in a determined effort to survive and remain competitive. Welding would save A total of twenty-two papers were presented at the symposium, and a a lot of swarf and time consuming metal cutting. selection from them will be found in the following pages. Further papers, He was sure that joining parts in assembly must now be the objective with the emphasis on the latest developments in welding techniques, will of the next manufacturing revolution. Automatic means of making joints be published in our next issue. NEW SHAPE FOR BOEING SST HE Boeing Company have now selected a moderately swept fixed Until recently two other SST designs were being evaluated by the com­ wing design with a conventional tail for their recommendation to the pany. They were the original variable sweep wing configuration designated Federal Aviation Administration and the airlines on January 15, in the 2707-200 which had been chosen in preference to the Lockheed delta place of the variable sweep configuration for the U.S. supersonic transport design, and the National Aeronautics and Space Administration SCAT 15 which was their original U.S. design competition winning proposal. fixed wing design. Because of the fine supersonic aerodynamic efficiency of the SCAT 15, a limited study of the design will be continued until the The company have said that detailed design and analysis work will end of 1968 aimed at developing advanced technology which may prove to continue until the end of the year in preparation for the formal submission be of use to the U.S. SST prototypes or the following production versions. of the new configuration. Following airline and government review and The Boeing engineer said that although the variable sweep concept still approval of the design, the construction of two prototype aircraft will had great potential for providing excellent supersonic and subsonic per­ begin at their Seattle facility. formance, certain configuration characteristics associated with the design The selection marks the final phase of a programme nearly a year long had resulted in high structural weights, with the result that the payload to improve the design performance of the U.S. SST before initiating the potential was reduced. As a result, work on the variable geometry wing build of two prototype aircraft. Boeing had asked the FAA early this year design for commercial application had been discontinued. for a year's extension to make sure that the prototypes would provide a The new design is smaller than the v.g. concept and its empty weight is sound foundation for the development of a commercially viable supersonic about 15 per cent less. With their choice of a wide span wing and conven­ aircraft. tional tail unit, Boeing are sacrificing some supersonic cruise efficiency for A Boeing engineer said that analysis of 4,800 hours of wind tunnel better low speed handling and control. The wing will have variable droop testing and other data developed during the year showed that a large span, flaps on the leading edge and on the trailing edge flaps will extend across fixed wing aircraft with a conventional tail and advanced high lift devices the full span. They argue that the wing planform selected has a light would be more efficient and economically profitable in commercial service structure in relation to its loading and that the weight efficiency easily off­ than the other configurations which had been studied. sets the higher drag. Another factor is that with this type of construction The new Boeing project, designated the 2707-300, will be primarily the use of advanced structural techniques and of composite materials will built of titanium. It will be about 280 ft. long, some 50 ft. high at the tail be facilitated. The take-off field length required is estimated to be between 8,000 and 9,000 ft., rather more than the earlier project, but the approach and will have a wing span of 141 ft. 8 in. with a leading edge sweep of speed of about 120 kts. is of the same order. The desired range is 4,000 50 deg. The prototype will have an a.u.w. of 635,000 lb. and will be miles, and reports indicate a payload of 234 tourist class passengers with powered by four General Electric of America GE 4 jet engines mounted in this requirement, but airlines might prefer to be offered a higher payload separate pods under the wing each with a design rating of 67,000 lb. t.o. thrust with burner and 50,500 lb. dry. The design cruise speed will be in exchange for a relatively small reduction in range, and the payload/ Mach 2·7 at altitudes of 60,000 ft. and above. range definition is still under discussion. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aircraft Engineering and Aerospace Technology Emerald Publishing

Welding for aerospace applications

Aircraft Engineering and Aerospace Technology , Volume 40 (11): 1 – Nov 1, 1968

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Publisher
Emerald Publishing
Copyright
Copyright © Emerald Group Publishing Limited
ISSN
0002-2667
DOI
10.1108/eb034434
Publisher site
See Article on Publisher Site

Abstract

November 1968 5 TH E MONTHLY JOURNAL OF AERONAUTICAL ENGINEERING HE use of welding in the aircraft industry has in the past been must be found. Welding might be one solution, but automatic riveting restricted, in general, to secondary structures owing to the lack of would no doubt provide serious competition to welding. The inspection of fully weldable aluminium alloys that had a strength after welding welding had always been difficult to say the least, and this single factor had comparable with that of the normal aluminium alloys used in aircraft detracted from its use. structures. The recent symposium on welding in the aerospace industry The materials we were moving towards in the struggle for a better sponsored by the Society of British Aerospace Companies has been of strength/weight ratio appeared to offer better weldability than at first great importance in showing that with the arrival of new materials and seemed probable. These new materials offering weight advantages had been techniques interest in welding as a major production tool is rapidly very much to the fore in the past four or five years, but the manufacturing growing, and that we are on the threshold of a very significant advance in capabilities had been somewhat secondary. The manipulation of these new this field. metals has however been developed satisfactorily as far as forming and The S.B.A.C., whose Fabricating Processes Panel of the S.B.A.C. machining are concerned. The question of welding had of course been Production Committee had originated the symposium, must have been given attention by the welding research engineers and welding of these new materials may now be able to offer some palliative to the eternal problem gratified by the response and the attendance. Rarely has the lecture of weight to the designer. theatre at the Royal Aeronautical Society been seen with such a high load factor as during the two day conference. The question of distortion and built-in stresses had also in the past been The opening address was given by Mr R. A. Courtman, Executive a major deterrent to the use of welding as an assembly process, but with Director - Manufacturing of Hawker Siddeley Aviation, Kingston. He the application of electron beam and other processes which localised the said that welding had been more readily accepted in the aero engine field heating of the workpiece, some of these problems could be overcome. However, some answers to the high tooling costs involved in these welding than in the airframe field, but he thought that we were on the point of processes still had to be found. obtaining acceptance of welding in the airframe and other fields in aero­ space. Mr Courtman believed that many of the recent advances in the manu­ In the past five years, Mr Courtman continued, the attention of produc­ facturing field had been entirely in the hands of the production engineer, numerical control in the machine shops, automatic pipe-bending, dualform tion engineers had been focused on other perhaps more fashionable pressing etc., but in the case of welding there was a very different climate. processes, in particular on numerically controlled machine tools which had stepped up metal removal to very high rates. Metal removal by mechanical Here the process still had to be sold to the designer, the chief inspector, as means had always been an expensive business and although numerical well as the capital expenditure controller. control had speeded up the process, the fundamental costs were still there. The new techniques in welding, and the very much improved control of A vast amount of expensive raw material, in some cases as much as 90 per the various control processes had stimulated the production and design cent, was reduced to swarf, which was virtually scrap material with a low engineers' interest, he concluded, and welding was now being presented as value. a viable commercial proposition with the reliability and the integrity necessary to warrant its wider use in airframe, hovercraft and similar Mr Courtman thought that the acceptance of numerical control in the manufacture. machine shops had stimulated manufacturing research in other fields in a determined effort to survive and remain competitive. Welding would save A total of twenty-two papers were presented at the symposium, and a a lot of swarf and time consuming metal cutting. selection from them will be found in the following pages. Further papers, He was sure that joining parts in assembly must now be the objective with the emphasis on the latest developments in welding techniques, will of the next manufacturing revolution. Automatic means of making joints be published in our next issue. NEW SHAPE FOR BOEING SST HE Boeing Company have now selected a moderately swept fixed Until recently two other SST designs were being evaluated by the com­ wing design with a conventional tail for their recommendation to the pany. They were the original variable sweep wing configuration designated Federal Aviation Administration and the airlines on January 15, in the 2707-200 which had been chosen in preference to the Lockheed delta place of the variable sweep configuration for the U.S. supersonic transport design, and the National Aeronautics and Space Administration SCAT 15 which was their original U.S. design competition winning proposal. fixed wing design. Because of the fine supersonic aerodynamic efficiency of the SCAT 15, a limited study of the design will be continued until the The company have said that detailed design and analysis work will end of 1968 aimed at developing advanced technology which may prove to continue until the end of the year in preparation for the formal submission be of use to the U.S. SST prototypes or the following production versions. of the new configuration. Following airline and government review and The Boeing engineer said that although the variable sweep concept still approval of the design, the construction of two prototype aircraft will had great potential for providing excellent supersonic and subsonic per­ begin at their Seattle facility. formance, certain configuration characteristics associated with the design The selection marks the final phase of a programme nearly a year long had resulted in high structural weights, with the result that the payload to improve the design performance of the U.S. SST before initiating the potential was reduced. As a result, work on the variable geometry wing build of two prototype aircraft. Boeing had asked the FAA early this year design for commercial application had been discontinued. for a year's extension to make sure that the prototypes would provide a The new design is smaller than the v.g. concept and its empty weight is sound foundation for the development of a commercially viable supersonic about 15 per cent less. With their choice of a wide span wing and conven­ aircraft. tional tail unit, Boeing are sacrificing some supersonic cruise efficiency for A Boeing engineer said that analysis of 4,800 hours of wind tunnel better low speed handling and control. The wing will have variable droop testing and other data developed during the year showed that a large span, flaps on the leading edge and on the trailing edge flaps will extend across fixed wing aircraft with a conventional tail and advanced high lift devices the full span. They argue that the wing planform selected has a light would be more efficient and economically profitable in commercial service structure in relation to its loading and that the weight efficiency easily off­ than the other configurations which had been studied. sets the higher drag. Another factor is that with this type of construction The new Boeing project, designated the 2707-300, will be primarily the use of advanced structural techniques and of composite materials will built of titanium. It will be about 280 ft. long, some 50 ft. high at the tail be facilitated. The take-off field length required is estimated to be between 8,000 and 9,000 ft., rather more than the earlier project, but the approach and will have a wing span of 141 ft. 8 in. with a leading edge sweep of speed of about 120 kts. is of the same order. The desired range is 4,000 50 deg. The prototype will have an a.u.w. of 635,000 lb. and will be miles, and reports indicate a payload of 234 tourist class passengers with powered by four General Electric of America GE 4 jet engines mounted in this requirement, but airlines might prefer to be offered a higher payload separate pods under the wing each with a design rating of 67,000 lb. t.o. thrust with burner and 50,500 lb. dry. The design cruise speed will be in exchange for a relatively small reduction in range, and the payload/ Mach 2·7 at altitudes of 60,000 ft. and above. range definition is still under discussion.

Journal

Aircraft Engineering and Aerospace TechnologyEmerald Publishing

Published: Nov 1, 1968

There are no references for this article.