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Method of production of aircraft fuselage station
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Method of production of aircraft fuselage station Evgeny Galkin Moscow Aviation Institute (National Research University), Volokolamskoe Highway, 4, Moscow 125993, Russian Federation
a r t i c l e
i n f o
Article history: Received 14 May 2019 Received in revised form 18 July 2019 Accepted 30 July 2019 Available online xxxx Keywords: Mathematical modeling Isothermal forging Aluminum 7075 Finite element analysis (FEA) QForm Fuselage station
a b s t r a c t The article represents the methodology of fuselage station volume pressing of AL 7075. Using mathematics modelling facilities there were determined characteristics of blank deformation considering its initial form and size. Due to the application of modelling there was developed the most rational method of fuselage station production that allows to receive a defectless piece considering the stress-strain behavior requirements and acceptable thermic and speed regimes for AL 7075 handling. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
1. Introduction A fuselage station (Fig. 1) represents a thin-walled article of deflected position, which provides a load dispatch all over the perimeter of the fuselage. At the current time the basic method of its production is the technology of metal-cutting of hot rolled and thermostrengthened aluminum plate (e.g. of aluminum 7075) using large duty CNC manufacturing machines [1,2]. In spite of process advantages, it also has a series of inconveniences [3]. Due to this fact an alternative process of deflected semi-finished item production for further of fuselage station production may serve the methods based on metal working process. Isothermal forging is one of perspective processes of production of fuselage stations which are made of high-strength difficult-to-form aluminum compositions like 7075. Nevertheless the final element analysis showed that the appliance of bars of rectangular or round section as blank parts leads to intolerable deformation degree for this group of alloys [4–6]. That is the reason for suggested appliance of extruded products with their size and form similar to those of the final product’s section.
2. Analysis of modelling of isothermal forging of extruded fuselage station blank part During the pressing stage it is suggested to make a blank part with its lateral dimensions different from those of fuselage station forging blank. (Fig. 2). The deformation degree which the blank part is supposed to receive during its isothermal forging in the curve die and the material mechanical hardening value which will fix the forging blank in workable arcuate state depend on the magnitude of the underpressing. Two variants are modeled for the analysis. The first (Fig. 3a) with decreased length of vertical tables by 3 mm on each side and the second one (Fig. 3b) by 6 mm on each side. During the first variant modelling in the conditions of isothermal forging the basic heating temperature for the aluminum 7075 reached 515 °C. The analysis of deformation modelling results shows the die fill rate and absence of defects. The maximum deformation degree accounted for 1,6 (Fig. 4). The analysis of maximum deformation degrees on Lagrangian lines shows the value of 60% at the T-shape table and 43% on the opposite edge of the forging part. The mechanical hardening of these zones will define the ability of conserving of the arcued form by the forging part.
E-mail address: [email protected] https://doi.org/10.1016/j.matpr.2019.07.725 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725
2
E. Galkin / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 1. Fuselage station cross section.
Fig. 3. Draft of blank part received by pressing. a – underpressing of tables by 3 mm on each side; b – underpressing of tables by 6 mm on each side.
Fig. 2. Draft of fuselage station forging blank.
During modelling it was defined that the metal temperature during the stamping increased from 515 °C up to 550 °C. Consequently, the results show that the alloy is in the state of its maximum moldability, however during the heating while stamping its temperature does not reach the level of possible material burning. Rated force for aluminum 7075 deformation is 130 MPag (Fig. 5). From this perspective, basing on the modelling results it can be assumed that the suggested technological process of fuselage station production using the scheme of punching with vertical tables underpressing and further isothermal stamping in the curve die impression showed its validity. The vertical tables underpressing value should be 3 mm on each side due to the fact that the maximum deformation degree in such case is 60. That is why the variant of 6 mm underpressing will not be considered otherwise it will lead to the increase of the deformation degree. The method of production during which the flat surface of the superior tool is located at a small angle of about 1% to the horizontal plane of the received forging part can be suggested as the measure of enhance of this variant of technological process. The necessity of providing an angle is imposed by the conditions in which will be conducted the deformation of the forging part in the curve die impression. While the curving, the external layers of the item will be exposed to tension stress and tension deformations, so the item gage will decrease. On the internal layers of the
Fig. 4. Effective deformation degree of extruded blank part stamping.
curved forging blank there will be an opposite result due to compressing deformations. The proposed angle in the stamp to the horizontal plane should compensate mentioned inequalities and to re-allocate metal among the zones of its deficit and excess. The scheme of die tooling with an inclination of 1° is represented in Fig. 6. The results of modelling between stamping of items with tables of 3 mm or 6 mm without inclination in the die tooling do not have substantial differences. During the process of deformation the die impression is filled completely, without any defects in the forging.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725
E. Galkin / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 5. Calculation of process power parameters.
The usability of isothermal volume punching firstly depends on the form and size of the initial blank part. The deformation of the blank part leads to high deformation degree (over 60%) and considerable metal heating. The most rational is the scheme of isothermal punching during which the initial straight blank part is made by pressing method and on the second transition the blank part is punched and curved during isothermal stamping. The appliance of this scheme allows to conduct punching with deformation degrees not over 60% with acceptable deformation heating which does not lead to burning of aluminum alloy 7075.
References
Fig. 6. Scheme of die tooling with an inclination of 1° to the horizontal plane of the forging part.
3. Conclusions According to the modelling results of the production of fuselage station of aluminum alloy 7075 using the method of isothermal volume punching the following inferences are made.
[1] Darrell A. Wade, in: Accurate FEA Prediction of Extrusion Forming To Improve Aircraft Design and Manufacturing, Boeing Publication, 2001, pp. 3–6. [2] Andrew Parris, in: Precision Stretch Forming of Metal for Precision Assembly, MIT, 1996, pp. 230–233. [3] I.A. Burchitz, Improvement of Springback Prediction in Sheet Metal Forming, 2008, pp. 149–150. ISBN 978-90-365-2656-2. [4] Handbook of Aluminum, Vol. 1. Physical Metallurgy and Processes. //George E. Totten., 2003, pp. 513–521. ISBN: 0-8247-0494-0. [5] S.I. Kishkina, I.N. Fridlyander, Aviation materials. Manual in 9 volumes, vol. 1, Moscow, 1982, pp. 173–176. [6] V.I. Elagin, V.A. Livanov, Structure and characteristics of semi-finished items of aluminum alloys. Manual, «Metallurgy», Moscow, 1984, pp. 97–103.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Method of production of aircraft fuselage station Evgeny Galkin Moscow Aviation Institute (National Research University), Volokolamskoe Highway, 4, Moscow 125993, Russian Federation
a r t i c l e
i n f o
Article history: Received 14 May 2019 Received in revised form 18 July 2019 Accepted 30 July 2019 Available online xxxx Keywords: Mathematical modeling Isothermal forging Aluminum 7075 Finite element analysis (FEA) QForm Fuselage station
a b s t r a c t The article represents the methodology of fuselage station volume pressing of AL 7075. Using mathematics modelling facilities there were determined characteristics of blank deformation considering its initial form and size. Due to the application of modelling there was developed the most rational method of fuselage station production that allows to receive a defectless piece considering the stress-strain behavior requirements and acceptable thermic and speed regimes for AL 7075 handling. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
1. Introduction A fuselage station (Fig. 1) represents a thin-walled article of deflected position, which provides a load dispatch all over the perimeter of the fuselage. At the current time the basic method of its production is the technology of metal-cutting of hot rolled and thermostrengthened aluminum plate (e.g. of aluminum 7075) using large duty CNC manufacturing machines [1,2]. In spite of process advantages, it also has a series of inconveniences [3]. Due to this fact an alternative process of deflected semi-finished item production for further of fuselage station production may serve the methods based on metal working process. Isothermal forging is one of perspective processes of production of fuselage stations which are made of high-strength difficult-to-form aluminum compositions like 7075. Nevertheless the final element analysis showed that the appliance of bars of rectangular or round section as blank parts leads to intolerable deformation degree for this group of alloys [4–6]. That is the reason for suggested appliance of extruded products with their size and form similar to those of the final product’s section.
2. Analysis of modelling of isothermal forging of extruded fuselage station blank part During the pressing stage it is suggested to make a blank part with its lateral dimensions different from those of fuselage station forging blank. (Fig. 2). The deformation degree which the blank part is supposed to receive during its isothermal forging in the curve die and the material mechanical hardening value which will fix the forging blank in workable arcuate state depend on the magnitude of the underpressing. Two variants are modeled for the analysis. The first (Fig. 3a) with decreased length of vertical tables by 3 mm on each side and the second one (Fig. 3b) by 6 mm on each side. During the first variant modelling in the conditions of isothermal forging the basic heating temperature for the aluminum 7075 reached 515 °C. The analysis of deformation modelling results shows the die fill rate and absence of defects. The maximum deformation degree accounted for 1,6 (Fig. 4). The analysis of maximum deformation degrees on Lagrangian lines shows the value of 60% at the T-shape table and 43% on the opposite edge of the forging part. The mechanical hardening of these zones will define the ability of conserving of the arcued form by the forging part.
E-mail address: [email protected] https://doi.org/10.1016/j.matpr.2019.07.725 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725
2
E. Galkin / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 1. Fuselage station cross section.
Fig. 3. Draft of blank part received by pressing. a – underpressing of tables by 3 mm on each side; b – underpressing of tables by 6 mm on each side.
Fig. 2. Draft of fuselage station forging blank.
During modelling it was defined that the metal temperature during the stamping increased from 515 °C up to 550 °C. Consequently, the results show that the alloy is in the state of its maximum moldability, however during the heating while stamping its temperature does not reach the level of possible material burning. Rated force for aluminum 7075 deformation is 130 MPag (Fig. 5). From this perspective, basing on the modelling results it can be assumed that the suggested technological process of fuselage station production using the scheme of punching with vertical tables underpressing and further isothermal stamping in the curve die impression showed its validity. The vertical tables underpressing value should be 3 mm on each side due to the fact that the maximum deformation degree in such case is 60. That is why the variant of 6 mm underpressing will not be considered otherwise it will lead to the increase of the deformation degree. The method of production during which the flat surface of the superior tool is located at a small angle of about 1% to the horizontal plane of the received forging part can be suggested as the measure of enhance of this variant of technological process. The necessity of providing an angle is imposed by the conditions in which will be conducted the deformation of the forging part in the curve die impression. While the curving, the external layers of the item will be exposed to tension stress and tension deformations, so the item gage will decrease. On the internal layers of the
Fig. 4. Effective deformation degree of extruded blank part stamping.
curved forging blank there will be an opposite result due to compressing deformations. The proposed angle in the stamp to the horizontal plane should compensate mentioned inequalities and to re-allocate metal among the zones of its deficit and excess. The scheme of die tooling with an inclination of 1° is represented in Fig. 6. The results of modelling between stamping of items with tables of 3 mm or 6 mm without inclination in the die tooling do not have substantial differences. During the process of deformation the die impression is filled completely, without any defects in the forging.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725
E. Galkin / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 5. Calculation of process power parameters.
The usability of isothermal volume punching firstly depends on the form and size of the initial blank part. The deformation of the blank part leads to high deformation degree (over 60%) and considerable metal heating. The most rational is the scheme of isothermal punching during which the initial straight blank part is made by pressing method and on the second transition the blank part is punched and curved during isothermal stamping. The appliance of this scheme allows to conduct punching with deformation degrees not over 60% with acceptable deformation heating which does not lead to burning of aluminum alloy 7075.
References
Fig. 6. Scheme of die tooling with an inclination of 1° to the horizontal plane of the forging part.
3. Conclusions According to the modelling results of the production of fuselage station of aluminum alloy 7075 using the method of isothermal volume punching the following inferences are made.
[1] Darrell A. Wade, in: Accurate FEA Prediction of Extrusion Forming To Improve Aircraft Design and Manufacturing, Boeing Publication, 2001, pp. 3–6. [2] Andrew Parris, in: Precision Stretch Forming of Metal for Precision Assembly, MIT, 1996, pp. 230–233. [3] I.A. Burchitz, Improvement of Springback Prediction in Sheet Metal Forming, 2008, pp. 149–150. ISBN 978-90-365-2656-2. [4] Handbook of Aluminum, Vol. 1. Physical Metallurgy and Processes. //George E. Totten., 2003, pp. 513–521. ISBN: 0-8247-0494-0. [5] S.I. Kishkina, I.N. Fridlyander, Aviation materials. Manual in 9 volumes, vol. 1, Moscow, 1982, pp. 173–176. [6] V.I. Elagin, V.A. Livanov, Structure and characteristics of semi-finished items of aluminum alloys. Manual, «Metallurgy», Moscow, 1984, pp. 97–103.
Please cite this article as: E. Galkin, Method of production of aircraft fuselage station, Materials Today: Proceedings, https://doi.org/10.1016/j. matpr.2019.07.725