# Aluminium Design and Construction

**By John Dwight (1999)**

Get the fundamentals on Aluminium Design from John Dwight. Learn about alloys, castings, fire risks and more in his comprehensive study!

**BRIEF CONTENTS **

### About aluminium

- General description
- The element
- The name
- The industrial metal
- Alloys
- Castings
- Supposed health risk
- Supposed fire risk

- Physical properties
- Comparison with steel
- The good points about aluminium
- The bad points

- History
- The precious metal stage
- The big breakthrough
- Early applications
- Establishment of the alloys
- The first major market

- Aluminium since 1945
- Growth in output
- New technology
- Structural engineering
- Architecture
- Land transport
- Marine usage

### Manufacture

- Production of aluminium metal
- Primary production
- Secondary metal

- Flat products
- Rolling mill practice
- Plate
- Sheet
- Tolerance on thickness
- Special forms of flat product

- Extruded sections
- Extrusion process
- Heat-treatment of extrusions
- Correction
- Dies
- Hollow sections
- Extrudability of different alloys
- Size and thickness limits
- Tolerances
- Design possibilities with extrusions

- Tubes
- Extruded tube
- Drawn tube
- Welded tube

### Fabrication

- Preparation of material
- Storage
- Cutting
- Holing
- Forming
- Machining

- Mechanical joints
- Bolting and screwing
- Friction-grip bolting
- Riveting

- Arc welding
- Use of arc welding
- MIG welding
- TIG welding
- Filler metal
- Weld inspection

- Friction-stir welding
- The process
- Features of FS welding
- Limitations
- Applications

- Other welding processes
- Adhesive bonding
- Use of bonding
- Surface preparation
- Two-component adhesives
- One-component adhesives
- Applying the adhesive
- Clamping
- Curing

- Protection and finishing
- General description
- Pretreatment
- Anodizing
- Painting
- Contact with other materials

### Aluminium alloys and their properties

- Numbering system for wrought alloys
- Basic system
- Standardization of alloys
- Work hardening
- The O and F conditions
- Relation between temper and tensile strength
- Availability of different tempers
- Heat-treated material

- Characteristics of the different alloy types
- Non-heat-treatable alloys
- Heat-treatable alloys

- Data on selected wrought alloys
- How mechanical properties are specified
- Specific alloys and their properties
- Comments on certain alloys
- Minimum bend radius
- Strength variation with temperature
- Properties of forgings

- Stress-strain curves
- Empirical stress-strain relation
- Stress-strain curve for minimum strength material

- Casting alloys
- Numbering system
- Three useful casting alloys

- Alloys used in joints
- Fastener materials
- Weld filler wire

- Corrosion
- Corrosion of exposed surfaces
- When to protect against corrosion
- Bimetallic corrosion

### Limit state design and limiting stresses

- Limit state design
- General description
- Definitions
- Limit state of static strength
- Serviceability limit state
- Limit state of fatigue

- The use of limiting stresses
- Limiting stresses based on material properties
- Derivation
- Procedure in absence of specified properties
- Listed values

- Limiting stresses based on buckling
- General form of buckling curves
- Construction of the design curves
- The design curves

### Heat-affected zone softening at welds

- General description
- Thermal control
- Patterns of softening
- Heat-treated material
- Work-hardened material
- Stress-strain curve of HAZ material
- Multi-pass welds
- Recovery time

- Severity of HAZ softening
- Softening factor
- Heat-treated material
- Work-hardened material

- Extent of the softened zone
- General considerations
- Nominal HAZ
- One-inch rule
- RD method
- Weld geometry
- Single straight MIG weld
- Variation of HAZ extent with weld size
- Overlapping HAZs
- Attachment welds
- Definition of an isolated weld (10A-rule)
- RD method, summary

- Application of HAZ data to design
- Design of members
- Design of joints

- Comparison with one-inch rule
- HAZ at TIG welds
- Difference between TIG and MIG welding
- Severity of softening with TIG welding
- Extent of softened zone for TIG welding

- HAZ at friction-stir welds

### Plate elements in compression

- General description
- Local buckling
- Types of plate element
- Plate slenderness parameter
- Element classification (compact or slender)
- Treatment of slender elements

- Plain flat elements in uniform compression
- Local buckling behaviour
- Limiting values of plate slenderness
- Slender internal elements
- Slender outstands
- Very slender outstands

- Plain flat elements under strain gradient
- Internal elements under strain gradient, general description
- Internal elements under strain gradient, classification
- Slender internal elements under strain gradient
- Outstands under strain gradient, general description
- Outstands under strain gradient, case T
- Outstands under strain gradient, case R

- Reinforced elements
- General description
- Limitations on stiffener geometry
- ‘Standard’ reinforcement
- Location of the stiffener
- Modified slenderness parameter
- Classification
- Slender reinforced elements

### Beams

- General approach
- Moment resistance of the cross-section
- Moment-curvature relation
- Section classification
- Uniaxial moment, basic formulae
- Effective section
- Hybrid sections
- Use of interpolation for semi-compact sections
- Semi-compact section with tongue plates
- Local buckling in an under-stressed compression flange
- Biaxial moment

- Shear force resistance
- Necessary checks
- Shear yielding of webs, method 1
- Shear yielding of webs, method 2
- Shear resistance of bars and outstands
- Web buckling, simple method
- Web buckling, tension-field action
- Inclined webs

- Combined moment and shear
- Low shear
- High shear, method A
- High shear, method B

- Web crushing
- Webs with bearing stiffeners
- Crushing of unstiffened webs

- Web reinforcement
- Types of reinforcement
- Tongue plates
- Transverse stiffeners
- End-posts

- Lateral-torsional buckling
- General description
- Basic check
- Equivalent uniform moment
- Limiting stress for LT buckling
- Slenderness parameter
- Beams with very slender compression flanges
- Effective length for LT buckling
- Beams of varying cross-section
- Effect of simultaneous side moment

- Beam deflection
- Basic calculation
- Beam of slender section

### Tension and compression members

- General approach
- Modes of failure
- Classification of the cross-section (compression members)

- Effective section
- General idea
- Allowance for HAZ softening
- Allowance for local buckling
- Allowance for holes

- Localized failure of the cross-section
- General yielding along the length
- Column buckling
- Basic calculation
- Column buckling stress
- Column buckling slenderness
- Column buckling of struts containing very slender outstands

- Torsional buckling
- General description
- Interaction with flexure
- ‘Type-R’ sections
- Sections exempt from torsional buckling
- Basic calculation
- Torsional buckling stress
- Torsional buckling slenderness
- Interaction factor
- Torsional buckling of struts containing very slender outstands
- Empirical slenderness formulae
- Torsional buckling of certain standardized sections

- Combined axial force and moment
- The problem
- Secondary bending in trusses
- Section classification
- Interaction formulae (P+uniaxial M)
- Alternative treatment (P+uniaxial M)
- Interaction formulae (P+biaxial M)
- Alternative treatment (P+biaxial M)
- Treatment of local buckling
- Eccentrically connected angles, channels and tees

### Calculation of section properties

- Summary of section properties used
- Plastic section modulus
- Symmetrical bending
- Unsymmetrical bending
- Bending with axial force
- Plastic modulus of the effective section

- Elastic flexural properties
- Inertia of a section having an axis of symmetry
- Inertias for a section with no axis of symmetry
- Product of inertia
- Inertia of the effective section
- Elastic section modulus
- Radius of gyration

- Torsional section properties
- The torque-twist relation
- Torsion constant, basic calculation
- Torsion constant for section containing ‘lumps’
- Polar inertia
- Warping factor
- Special LT buckling factor

- Warping calculations
- Coverage
- Numbering the elements
- Evaluation of warping
- Formula for the warping factor
- Bisymmetric and radial-symmetric sections
- Skew-symmetric sections
- Monosymmetric sections, type 1
- Monosymmetric sections, type 2
- Asymmetric sections

### Joints

- Mechanical joints (non-torqued)
- Types of fastener
- Basic checking procedure
- Joints in shear, fastener force arising
- Joints in shear, fastener resistance
- Joints in shear, member failure
- Joints in tension, fastener force arising
- Joints in tension, fastener resistance
- Interaction of shear and tension
- Comparisons
- Joints made with proprietary fasteners

- Mechanical joints (friction-grip)
- General description
- Bolt material
- Ultimate limit state (shear loading)
- Serviceability limit state (shear loading)
- Bolt tension and reaction force
- Slip factor
- Serviceability factor

- Welded joints
- General description
- Basic checking procedure
- Weld force arising
- Calculated resistance, weld-metal failure
- Calculated resistance, fusion-boundary failure
- Welded joints carrying axial moment
- Welds under combined loading
- Friction-stir welds

- Bonded joints
- General description
- Specification of the adhesive
- Surface preparation
- Effect of moisture
- Factors affecting choice of adhesive
- Creep
- Peeling
- Mechanical testing of adhesives
- Glue-line thickness
- Properties of some selected adhesives
- Resistance calculations for bonded joints
- Testing of prototype joints

### Fatigue

- General description
- Possible ways of handling fatigue
- Checking procedure (safe life)
- Constant amplitude loading
- Variable amplitude loading
- Design life
- Stress range
- Stress-range spectrum

- Representative stress
- Method A
- Method B

- Classification of details
- The BS.8118 classification
- Friction-stir welds
- Bonded joints

- Endurance curves
- Instructions to fabricator
- Improvement measures
- Fatigue of bolts
- Basic approach
- Endurance curves for steel
- Variation of bolt tension