Calculating Compression of Bored Out Steel Column - Stress & Strain

[JRYD]

I have been given a question to recap by my tutor as i find this topic fairly difficult.

A steel column is 90cm long and 150mm diameter. If a hole 100mm diameter and 60cm long is bored out, calculate the total compression of the column when carrying a load of 1MN. Take the modulus of elasticity for steel, E = 200 GN/m squared.

I have done similar questions to this before but have never learned how to calculate the compression of a bored out steel column!

Any help on how to start this off will be very much appreciated!

 

[radou]

Well, if you bore a hole, you change the cross section, right? How does stress relate to cross section?