Aluminium Design and Construction John Dwight

where A is the section area (mm 2 ) and t the plate thickness (mm). Table
1.1 compares aluminium with other metals.
(b) Elastic constants
Aluminium is a springy metal with a relatively low modulus of elasticity
(E). For the pure metal at room temperature it compares with steel as
follows:
Pure aluminium E=69 kN/mm 2
Structural steel E=205 kN/mm 2
while the value for wrought alloys lies in the range 69–72 kN/mm. For
design purposes British Standard BS.8118 adopts a standard figure of
E=70 kN/mm 2 , which is similar to that for glass. For aluminium E
decreases steadily with temperature, dropping to 67 kN/mm 2 at 100°C
and 59 kN/mm 2 at 200°C
Poisson’s ratio (v) is higher than the accepted figure of 0.30 used for
steel and should be taken equal to 0.33, based on the work of Baker and
Roderick at Cambridge in 1948 [2].
The corresponding figure for the shear modulus (G), based on the
above values of E and v, is:
(c) Thermal expansion
The coefficient of linear � expansion for pure aluminium at room
temperature compares with steel as follows:
Table 1.1 Density of metallic elements
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