870 T.Dursun,C.Soutis/Materials and Design 56(2014)862-871 The infrastructure and knowledge base has become mature.How- It is believed that developments of advanced hybrid materials. ever,with the introduction of high performance polymer compos- like fibre metal laminates could provide additional opportunities ites in the application of airframe designs reduced the role of for aluminium alloys and new material options for the airframe aluminium alloys up to some extent due composites'high specific industry. properties,reduced weight,fatigue performance and corrosion resistance(Boeing 787.Airbus A350).In order for aluminium alloys References to remain attractive in the airframe construction and compete with and/or be compatible with currently used polymer composites,re- [1]Campbell FC.Manufacturing technology for aerospace structural search activities on the improvement of structural performance, materials.Elsevier:2006. weight and cost reductions are needed.Recent developments in [2]Warren AS.Developments and challanges for aluminium -A Boeing perspective.Mater Forum 2004:28:24-31. high strength Al-Zn and Al-Li alloys,damage tolerant Al-Cu and [3]Hombergsmeier E Development of advanced laminates for aircraft structures. Al-Li alloys,have been successful in improving the static strength, In:25th International congress of the aeronautical sciences,Hamburg. fracture toughness,fatigue and corrosion resistance through the Germany:2006. [4]Vlot A.Vogelesang LB.De Vries TJ.Towards application of fibre metal design and control of chemical composition,and/or through the laminates in large aircraft.Aircr Eng Aerosp Technol 1999:7:558-70. development of more effective heat treatments.It has been seen [5]Gunnink JW.Vlot A.De Vries TJ.Van Der Hoeven W.GLARE technology from this review that major improvements of aerospace alumin- development 1997-2000.Appl Compos Mater 2002:9:201-19. [6]Vogelesang LB.Vlot A.Development of fibre metal laminates for advanced ium alloys are due to optimised solute content and solute ratios aerospace structures.J Mater Process Technol 2000:103:1-5. in order to achieve better property balance.The use of new disper- 17]Vermeeren CAJR.An historic overview of the development of fibre metal soid-processing combinations results in desired grain structures laminates.Appl Compos Mater 2003:10:189-205. that provide better damage tolerance.Improvements in under- [8]Wu G.Yang JM.The mechanical behavior of GLARE laminates for aircraft structures.JOM 2005:57:72-9. standing and modelling of the hardening system and especially [9]Alderliesten RC.Homan J.Fatigue and damage tolerance issues of Glare in the effect of minor element addition will help improvements in aircraft structures.Int J Fatigue 2006:28:1116-23. mechanical properties. [10]Alderliesten RC,Benedictus R.Fiber/metal composite technology for future Current research activities for both composites and aluminium include:improvement on mechanical properties,reduction of 2007. manufacturing,maintenance and repair costs,prevention of corro- [11]Vermeeren CAJR,Beumler T.De Kanter JLCG.Van Der Jagt OC.Out BCL Glare design aspects and philosophies.Appl Compos Mater 2003:10:257-76. sion and fatigue and ability to perform reliably throughout its ser- [12]Soltani P.Keikhosravy M,Oskouei RH.Soutis C Studying the tensile behaviour vice life. of GLARE laminates:a finite element modelling approach.Appl Compos Mater In order to use the advantage of improvements in mechanical 2011·18271-82. [13]Flower HM,Soutis C.Materials for airframes.Aeronat J 2003:331-41 properties of advanced aluminium alloys and sustain the structural [14]Soutis C.Recent advances in building with composites.Plast Rubber Compos: integrity in mechanically fastened aircraft structures a special Macromol Eng 2009:38:359-66. attention should be paid on the fretting fatigue.There is need to [15]Diamanti K.Soutis C.Structural health monitoring techniques for aircraft composite structures.Prog Aerosp Sci 2010:46:343-52. understand the fretting behaviour of recently developed Al-Li al- [16]Giurgiutiu V,Soutis C.Enhanced composites integrity through structural loys such as 2050 and 2099 and fibre metal laminates in mechan- health monitoring.Appl Compos Mater 2012:1-17. ically fastened aircraft joints. [17]Soutis C.Mohamed G.Hodzic A Performance of GLARE panels subjected to In addition to weight reduction and improvement on the struc- intense pressure pulse loading.Aeronaut J 2012:116:667-79. [18]Mohamed G.Soutis C.Hodzic A.Multi-material arbitrary-lagrangian eulerian tural performance the materials,cost reduction through the devel- formulation for blast-induced fluid-structure interaction in fibre metal opment on the manufacturing techniques is also a key issue. laminates.AlAA 2012:50:1826-33. Manufacturing constitutes the biggest portion of the cost of the air- [19]Cassada W.Liu J.Staley J.Aluminium alloys for aircraft structures.Adv Mater Processes 2002:27-9. frame.Therefore great effort is being spent to reduce the produc- [20]Starke EA.Staley JT.Application of modern aluminium alloys to aircraft.Prog tion costs and part count via introducing high-speed machining. Aerosp Sci1996:32:131-72. novel assembly techniques such as laser beam welding and fric- [21]Williams JC,Starke EA.Progress in structural materials for aerospace systems. Acta Mater2003:51:5775-99. tion-stir welding.For example,unlike most conventional aerospace [22]Merati A.Materials replacement for aging aircraft.RTO-AG-AVT-140 [Chapter alloys,the fusion weldability of Al-Cu-Li alloys could introduce 241. new opportunities in the fabrication of fuselage.Therefore,in addi- [23]Verma BB.Atkinson JD.Kumar M.Study of fatigue behaviour of 7475 aluminium alloy.Bull Mater Sci 2001:24:231-6. tion to metallurgical developments with the combination of other [24]Smith B.The Boeing 777.Adv Mater Processes 2003:41-4. manufacturing techniques than the riveting will help reach opti- [25]Chen YQ,Pan SP,Zhou MZ,Yi DQ,Xu DZ.Xu Y.Effects of inclusions,grain mised damage tolerant designs. boundaries and grain orientations on the fatigue crack initiation and High strain-rate superplastic forming and casting are also draw- propagation behavior of 2524-T3 Al alloy.Mater Sci Eng A 2013:580:150-8. [26]Zheng ZQ.Cai B.Zhai T.Li SC.The behavior of fatigue crack initiation and ing attention as cost effective solutions.Advanced joining tech- propagation in AA2524-T34 alloy.Mater Sci Eng A 2011:528:2017-22. niques will also make aluminium structures more affordable. [27]Necsulescu DA.The effects of corrosion on the mechanical properties of The airframes and other structural parts will continue to be aluminum alloy 7075-T6.UPB Sci Bull 2011:73. [28]Lam FD,Menzemer CC,Srivatsan TS.A study to evaluate and understand the composed of different materials including aluminium,titanium response of aluminum alloy 2026 subjected to tensile deformation.Mater Des steel,polymer composites and fibre metal laminates depending 2010:31:166-75. on the balance of structural and economical factors.Weight sav- [29]Li IX,Zhai T.Garratt MD.Bray GH.Four point bend fatigue of AA2026 aluminum alloy.Metull Mater Trans A 2005:36A:2529-39 ing through increased specific strength and/or stiffness and (30]Pantelakis SG.Chamos AN,Kermanidis A.A critical consideration of use of Al- affordability (procurement,maintenance and repair costs)are cladding for protecting aircraft aluminum alloy 2024 against corrosion.Theor the major drivers for the development and selection of materials Appl Fract Mec 2012:57:36-42 [31]Ziemian CW,Sharma MM,Bouffard BD.Nissley T,Eden TI.Effect of substrate for civil airframes.In selecting new materials for aircraft applica- surface roughening and cold spray coating on the fatigue life of AA2024 tions,there should be no reduction on the levels of safety that is specimens.Mater Des 2014:54:212-21. already reached with conventional alloys.Fatigue resistance,cor- [32]Shi H.Han EH,Liu F.Kallip S.Protection of 2024-T3 aluminium alloy by corosIon resistant phytic acid conversion coating.Appl Surf Sci rosion resistance and damage tolerance are all very important 2013280325-31. mechanical properties of airframe materials that affect the [33]Kim ST.Tadjiev D.Yang HT.Fatigue life prediction under random loading inspection,maintenance and repair costs and this is where mod- conditions in 7475-T7351 aluminum alloy using the RMS model.Int J Damage Mech2006:15:89-102. ern aluminium alloys could compete effectively with polymer [34]Warner T.Recently-developed aluminium solutions for aerospace composites. applications.Mater Sci Forum 2006:519-521:1271-8.The infrastructure and knowledge base has become mature. How￾ever, with the introduction of high performance polymer compos￾ites in the application of airframe designs reduced the role of aluminium alloys up to some extent due composites’ high specific properties, reduced weight, fatigue performance and corrosion resistance (Boeing 787, Airbus A350). In order for aluminium alloys to remain attractive in the airframe construction and compete with and/or be compatible with currently used polymer composites, re￾search activities on the improvement of structural performance, weight and cost reductions are needed. Recent developments in high strength Al–Zn and Al–Li alloys, damage tolerant Al–Cu and Al–Li alloys, have been successful in improving the static strength, fracture toughness, fatigue and corrosion resistance through the design and control of chemical composition, and/or through the development of more effective heat treatments. It has been seen from this review that major improvements of aerospace alumin￾ium alloys are due to optimised solute content and solute ratios in order to achieve better property balance. The use of new disper￾soid-processing combinations results in desired grain structures that provide better damage tolerance. Improvements in under￾standing and modelling of the hardening system and especially the effect of minor element addition will help improvements in mechanical properties. Current research activities for both composites and aluminium include: improvement on mechanical properties, reduction of manufacturing, maintenance and repair costs, prevention of corro￾sion and fatigue and ability to perform reliably throughout its ser￾vice life. In order to use the advantage of improvements in mechanical properties of advanced aluminium alloys and sustain the structural integrity in mechanically fastened aircraft structures a special attention should be paid on the fretting fatigue. There is need to understand the fretting behaviour of recently developed Al–Li al￾loys such as 2050 and 2099 and fibre metal laminates in mechan￾ically fastened aircraft joints. In addition to weight reduction and improvement on the struc￾tural performance the materials, cost reduction through the devel￾opment on the manufacturing techniques is also a key issue. Manufacturing constitutes the biggest portion of the cost of the air￾frame. Therefore great effort is being spent to reduce the produc￾tion costs and part count via introducing high-speed machining, novel assembly techniques such as laser beam welding and fric￾tion-stir welding. For example, unlike most conventional aerospace alloys, the fusion weldability of Al–Cu–Li alloys could introduce new opportunities in the fabrication of fuselage. Therefore, in addi￾tion to metallurgical developments with the combination of other manufacturing techniques than the riveting will help reach opti￾mised damage tolerant designs. High strain-rate superplastic forming and casting are also draw￾ing attention as cost effective solutions. Advanced joining tech￾niques will also make aluminium structures more affordable. The airframes and other structural parts will continue to be composed of different materials including aluminium, titanium, steel, polymer composites and fibre metal laminates depending on the balance of structural and economical factors. Weight sav￾ing through increased specific strength and/or stiffness and affordability (procurement, maintenance and repair costs) are the major drivers for the development and selection of materials for civil airframes. In selecting new materials for aircraft applica￾tions, there should be no reduction on the levels of safety that is already reached with conventional alloys. Fatigue resistance, cor￾rosion resistance and damage tolerance are all very important mechanical properties of airframe materials that affect the inspection, maintenance and repair costs and this is where mod￾ern aluminium alloys could compete effectively with polymer composites. It is believed that developments of advanced hybrid materials, like fibre metal laminates could provide additional opportunities for aluminium alloys and new material options for the airframe industry. References [1] Campbell FC. Manufacturing technology for aerospace structural materials. Elsevier; 2006. [2] Warren AS. Developments and challanges for aluminium – A Boeing perspective. Mater Forum 2004;28:24–31. [3] Hombergsmeier E. Development of advanced laminates for aircraft structures. In: 25th International congress of the aeronautical sciences, Hamburg, Germany; 2006. [4] Vlot A, Vogelesang LB, De Vries TJ. Towards application of fibre metal laminates in large aircraft. Aircr Eng Aerosp Technol 1999;7:558–70. [5] Gunnink JW, Vlot A, De Vries TJ, Van Der Hoeven W. GLARE technology development 1997–2000. Appl Compos Mater 2002;9:201–19. [6] Vogelesang LB, Vlot A. Development of fibre metal laminates for advanced aerospace structures. J Mater Process Technol 2000;103:1–5. [7] Vermeeren CAJR. An historic overview of the development of fibre metal laminates. Appl Compos Mater 2003;10:189–205. [8] Wu G, Yang JM. The mechanical behavior of GLARE laminates for aircraft structures. JOM 2005;57:72–9. [9] Alderliesten RC, Homan JJ. Fatigue and damage tolerance issues of Glare in aircraft structures. Int J Fatigue 2006;28:1116–23. [10] Alderliesten RC, Benedictus R. Fiber/metal composite technology for future primary aircraft structures. In: 48th AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference. Honolulu, Hawaii, 23–26 April 2007. [11] Vermeeren CAJR, Beumler T, De Kanter JLCG, Van Der Jagt OC, Out BCL. Glare design aspects and philosophies. Appl Compos Mater 2003;10:257–76. [12] Soltani P, Keikhosravy M, Oskouei RH, Soutis C. Studying the tensile behaviour of GLARE laminates: a finite element modelling approach. Appl Compos Mater 2011;18:271–82. [13] Flower HM, Soutis C. Materials for airframes. Aeronat J 2003:331–41. [14] Soutis C. Recent advances in building with composites. Plast Rubber Compos: Macromol Eng 2009;38:359–66. [15] Diamanti K, Soutis C. Structural health monitoring techniques for aircraft composite structures. Prog Aerosp Sci 2010;46:343–52. [16] Giurgiutiu V, Soutis C. Enhanced composites integrity through structural health monitoring. Appl Compos Mater 2012:1–17. [17] Soutis C, Mohamed G, Hodzic A. Performance of GLARE panels subjected to intense pressure pulse loading. Aeronaut J 2012;116:667–79. [18] Mohamed G, Soutis C, Hodzic A. Multi-material arbitrary-lagrangian eulerian formulation for blast-induced fluid-structure interaction in fibre metal laminates. AIAA J 2012;50:1826–33. [19] Cassada W, Liu J, Staley J. Aluminium alloys for aircraft structures. Adv Mater Processes 2002:27–9. [20] Starke EA, Staley JT. Application of modern aluminium alloys to aircraft. Prog Aerosp Sci 1996;32:131–72. [21] Williams JC, Starke EA. Progress in structural materials for aerospace systems. Acta Mater 2003;51:5775–99. [22] Merati A. Materials replacement for aging aircraft. RTO-AG-AVT-140 [Chapter 24]. [23] Verma BB, Atkinson JD, Kumar M. Study of fatigue behaviour of 7475 aluminium alloy. Bull Mater Sci 2001;24:231–6. [24] Smith B. The Boeing 777. Adv Mater Processes 2003:41–4. [25] Chen YQ, Pan SP, Zhou MZ, Yi DQ, Xu DZ, Xu Y. Effects of inclusions, grain boundaries and grain orientations on the fatigue crack initiation and propagation behavior of 2524-T3 Al alloy. Mater Sci Eng A 2013;580:150–8. [26] Zheng ZQ, Cai B, Zhai T, Li SC. The behavior of fatigue crack initiation and propagation in AA2524-T34 alloy. Mater Sci Eng A 2011;528:2017–22. [27] Necsulescu DA. The effects of corrosion on the mechanical properties of aluminum alloy 7075–T6. UPB Sci Bull 2011:73. [28] Lam FD, Menzemer CC, Srivatsan TS. A study to evaluate and understand the response of aluminum alloy 2026 subjected to tensile deformation. Mater Des 2010;31:166–75. [29] Li JX, Zhai T, Garratt MD, Bray GH. Four point bend fatigue of AA2026 aluminum alloy. Metull Mater Trans A 2005;36A:2529–39. [30] Pantelakis SG, Chamos AN, Kermanidis A. A critical consideration of use of Al￾cladding for protecting aircraft aluminum alloy 2024 against corrosion. Theor Appl Fract Mec 2012;57:36–42. [31] Ziemian CW, Sharma MM, Bouffard BD, Nissley T, Eden TJ. Effect of substrate surface roughening and cold spray coating on the fatigue life of AA2024 specimens. Mater Des 2014;54:212–21. [32] Shi H, Han EH, Liu F, Kallip S. Protection of 2024-T3 aluminium alloy by corrosion resistant phytic acid conversion coating. Appl Surf Sci 2013;280:325–31. [33] Kim ST, Tadjiev D, Yang HT. Fatigue life prediction under random loading conditions in 7475–T7351 aluminum alloy using the RMS model. Int J Damage Mech 2006;15:89–102. [34] Warner T. Recently-developed aluminium solutions for aerospace applications. Mater Sci Forum 2006;519–521:1271–8. 870 T. Dursun, C. Soutis / Materials and Design 56 (2014) 862–871