A structural steel beam dynamics?

anonymous

A structural steel beam is 15m long when it is installed at 20oC. How much does the length change over the temperature extremes: –30oC to 50oC? Take for copper = 11 10–6

devarat

Answer :-

Change of Length = 15.6 mm;

Procedure : -

The law of thermal expansion is

dL/L = a*dT --- --- --- --- --- --- --- (1);

Where,

dL = Change of Length;

L = Original Length;

a = Thermal Expansion Coefficient;

dT = Change of Temperature;

Here, dT = 50+30 = 80 C;

You have given that a = 11e-6 per C;

For Steel, however,

a = 13e-6 per C;

Taking my value of 'a' and applying Formula-(1),

we get,

dL = 15.6 mm;

Taking your value of 'a' and applying Formula-(1),

we get,

dL = 13.2 mm;