Question About Beams and EI Values

[christian Bendis]

Hello all

I wanted to ask about beams.

I have the following structure:-

P1.png

My question is that given this structure is composed of 2 x different EI values (the first 4m being EI and the last 8m being 2EI) then what would the purpose of using 2 different EI materials on a beam?

I can only think of the fact that over the 2EI length the deflections and moments need to be reduced but are there any other reasons?

Secondly how can this type of beam be constructed? off the top of my head I would assume that 2 members of EI are either welded or bolted together?

Any ideas or web sites you can direct me to?

Thank you.

[Kelly_Bramble]

My question is that given this structure is composed of 2 x different EI values (the first 4m being EI and the last 8m being 2EI) then what would the purpose of using 2 different EI materials on a beam?

Academic.... this is homework created by somebody that wanted to pose a math challenge to students.