Aluminium Design and Construction John Dwight

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2.4.3 Welded tube This is the cheapest way of making thin tube. Cold-reduced strip is roll-formed to a circular shape and then fed past a welding head to produce the final product. Such tube is produced in long lengths from non-heat-treatable coiled strip (3xxx or 5xxx-series alloy). A major market is for irrigation pipe. Copyright 1999 by Taylor & Francis Group. All Rights Reserved.
CHAPTER 3 Fabrication 3.1 PREPARATION OF MATERIAL 3.1.1 Storage Aluminium materials waiting to be fabricated are obviously best stored in the dry. But if they do get wet, at least they will not rust. One possible problem during storage is water staining, which appears as ugly blotches varying from white to dark grey [8]. This occurs when water is trapped between flat aluminium surfaces, and sometimes happens as a result of condensation when metal is brought in from the cold. Water stains have no effect on structural performance, but must be avoided when good appearance is needed. 3.1.2 Cutting Most of the techniques used for cutting steel are suitable for aluminium, including shearing, sawing, notching, nibbling and routing. Sawing, in particular, is quicker and easier than for steel, provided the appropriate tooth size and cutting speed are used. Circular saws and band saws are both employed. Flame cutting is, unfortunately, no good for aluminium because of the ragged edge produced. For profiled cuts, it is necessary to use band sawing or plasma cutting. 3.1.3 Holing Drilling of aluminium is faster than with steel, and is the normal method of making holes. When punching is used, it is desirable to punch to 75% of the final hole size and drill out. This applies especially when the diameter is less than the thickness, leading to enlargement of the hole on the tearout side. The practice of predrilling holes for fasteners to a smaller diameter, and reaming after assembly, is commoner in aluminium than in steel. Hole spacing and edge distances must not be made too small, so as to avoid premature tearing in joints loaded in shear. British Standard Copyright 1999 by Taylor & Francis Group. All Rights Reserved.
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Aluminium Design and Construction C
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First published 1999 by E & FN Spon
Page 5 and 6: 2.2.1 Rolling mill practice 2.2.2 P
Page 7 and 8: 5 Limit state design and limiting s
Page 9 and 10: 8.2.6 Use of interpolation for semi
Page 11 and 12: 10.3.2 Inertias for a section with
Page 13 and 14: Preface Aluminium is easily the sec
Page 15 and 16: List of symbols The following symbo
Page 17 and 18: uu, vv principal axes w effective s
Page 19 and 20: 1.1.3 The industrial metal It is on
Page 21 and 22: where A is the section area (mm 2 )
Page 23 and 24: 1.3.1. The good points about alumin
Page 25 and 26: Deflection Because of the lower mod
Page 27 and 28: 1.4.4 Establishment of the alloys I
Page 29 and 30: 1.5.2 New technology Most of alumin
Page 31 and 32: large span, where self-weight is a
Page 33 and 34: These tend to be in all-aluminium c
Page 35 and 36: Close-up of the M-dec system, which
Page 37 and 38: Aluminium glazing system for commer
Page 39 and 40: Nat West Media Centre, Lords Cricke
Page 41 and 42: The main requirements for the produ
Page 43 and 44: in which t and w are in mm. These a
Page 45 and 46: Figure 2.1 Extrusion process (direc
Page 47 and 48: Figure 2.2 Typical extrusion die. t
Page 49 and 50: Figure 2.6 ‘Semi-hollow’ profil
Page 51 and 52: especially the stronger alloys in t
Page 53 and 54: Figure 2.9 Conventional profiles. 2
Page 55: 2.4 TUBES By tubes we mean hollow s
Page 59 and 60: Figure 3.1 Alternative designs for
Page 61 and 62: Figure 3.2 Thread insert. a coil-sp
Page 63 and 64: 3.3 ARC WELDING 3.3.1 Use of arc we
Page 65 and 66: adjusted. The technique is claimed
Page 67 and 68: For welds of minimum or fatigue qua
Page 69 and 70: Figure 3.5 Friction-stir welding: s
Page 71 and 72: are, and the designer/fabricator mu
Page 73 and 74: cartridge, and mixing takes place a
Page 75 and 76: 3.7.4 Painting Alloys having durabi
Page 77 and 78: Where a range is given, as for the
Page 79 and 80: will be only slightly above that fo
Page 81 and 82: heating the metal to a temperature
Page 83 and 84: Table 4.4 Characteristics of differ
Page 85 and 86: softening in the heat-affected zone
Page 87 and 88: 60 alloys, are: BSEN.485 plate and
Page 89 and 90: Firure 4.3 Nominal composition and
Page 91 and 92: popular alloys in the series are: 6
Page 93 and 94: Figure 4.6 Variation of tensile str
Page 95 and 96: undercarriages of aircraft. They ar
Page 97 and 98: Figure 4.11 Minimum stress-strain c
Page 99 and 100: AC.51400 This is another non-heat-t
Page 101 and 102: times that of the actual pits) prod
Page 103 and 104: The severity of bimetallic corrosio
Page 105 and 106: Nominal loading. Nominal loads are
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2. Material factor (� m ). In the
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design does not, because stress at
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Table 5.2 Summary of limiting stres
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Figure 5.4 Plastic strain at workin
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example, a reduced value might be t
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The parameter � depends purely on
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CHAPTER 6 Heat-affected zone soften
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area of softening. With 7xxx-type m
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Figure 6.3 Typical hardness plots a
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6.4 SEVERITY OF HAZ SOFTENING 6.4.1
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Figure 6.6 Categories of welded joi
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Figure 6.10 One-inch rule, extent o
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e allowed for in design by replacin
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Figure 6.13 Predicted area (A z ) o
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Figure 6.15 Overlapping HAZs. nomin
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In determining A zp , an appropriat
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failure plane in the HAZ, close to
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With MIG welding, an electrode-posi
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CHAPTER 7 Plate elements in compres
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(a) Compression member elements The
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Table 7.1 Classification of element
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Figure 7.4 Slender internal element
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Figure 7.7 shows curves of � ° p
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(7.9a) (7.9b) The strain gradient c
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(through the centroid) for ß S . F
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Figure 7.13 Outstands under strain-
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Figure 7.15 Reinforced elements. Th
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Figure 7.18 Stiffener location for
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Figure 7.20 Slender reinforced inte
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CHAPTER 8 Beams 8.1 GENERAL APPROAC
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8.2.2 Section classification The di
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that for the gross section. It woul
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the usual manner. Line 1 in the fig
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1. Fully compact sections. The limi
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Figure 8.8 Transverse and longitudi
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8.3.4 Shear resistance of bars and
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Figure 8.12 Tension-field action. i
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Figure 8.14 Moment/shear interactio
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depending on the estimated degree o
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where a is the stiffener spacing an
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plates (if fitted), p v =limiting m
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ending moment diagram. Two cases ar
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Figure 8.23 Sections covered in Tab
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where: I yy , I vv =inertia about m
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post (Section 8.6.4) or by some oth
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Figure 8.26 Components of deflectio
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9.1.2 Classification of the cross-s
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hole. Alternatively, it might fail
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Figure 9.2 Limiting stress p b for
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The determination of l involves a c
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Figure 9.6 Monosymmetric section. I
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Figure 9.9 Limiting stress p b for
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where s=� s /� t s =slenderness
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Figure 9.11 Type-R sections covered
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Figure 9.14 Four standardized profi
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9.7.2 Secondary bending in trusses
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Table 9.5 Necessary checks for memb
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Figure 9.18 Axial load with biaxial
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1. Tension members. The localized f
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Figure 10.1 Symmetric plastic bendi
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We now turn to monosymmetric sectio
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distance of its centroid from the n
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Figure 10.6 Elements of sections. I
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10.3.3 Product of inertia The produ
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Usually the conditions are such as
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Table 10.2 Torsion constant. Factor
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Figure 10.12 Warping. Conventional
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where b, t=element width and thickn
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10.5.3 Evaluation of warping When t
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For sections where the position of
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(10.31) where: e=distance that S li
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10.5.9 Asymmetric sections Before s
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CHAPTER 11 Joints This chapter cons
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the use of limiting stresses taken
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and the summation is made for all t
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Figure 11.3 Interaction diagram for
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k in order to give a fair compariso
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3. The design is satisfactory if fo
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When the method of surface preparat
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11.3.3 Weld force arising In many c
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Table 11.6 Limiting stress p w (N/m
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where p a =limiting stress for unwe
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Figure 11.11 Interaction diagram fo
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Manufacturers of structural adhesiv
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11.4.6 Creep Shear strength figures
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Figure 11.15 Effect of glue-line th
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Table 11.7 and Figure 11.17 provide
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11.4.11 Resistance calculations for
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high value reflects the various unc
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therefore usually presented in term
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For example: The loading spectrum i
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act on the structure. However, BS.8
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Figure 12.4 Crack propagation: (a)
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12.5 CLASSIFICATION OF DETAILS 12.5
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i.e. a joint extending in the same
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when the design life is low or when
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Methods (2) and (3) are difficult t
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it reverts to line 1. The slope s o
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Aluminium Design and Construction John Dwight

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