kingbeam-check design 1

[bplech]

A beam is constructed of a 12 inch deepx6.5 inch flange tapered flange beam and on top of it is a 9"x13" wood hem fir beam. Simple span 10'-6". The loads are three concentrated joist loads and a uniform load, from two 25,000 pound storage tanks for a liquid soap product. Individually the wood beam or the steel beam would be overloaded, but togeather the structure integrity is fine without any sign of distress. I know that because the tanks have been there for years, except now an insurance company wants the verification calculations from a registered engineer. I would like to model the problem using a RISA 3d if possible to check the structural strength of this beam. Any suggestions?

 

[jec67]

Risa will get you the answer you are looking for. The problem you have stated comes down to the proportions of Young's modulus x Moment of inertia for the two sections. For the arrangement you have described, the two sections will go through an equal amount of deflection. The load will be distributed to the two sections based on the stiffnesses of the two sections. Since the lengths (I am assuming) of the steel and timber are the same, the variables are E and I for each section.

You can also perform this analysis by hand.

I estimate about 75% of the load will go to the steel beam, based on some assumed values for the steel cross section and young's modulus for the timber. Please let us know what you come up with in your analysis.

Good luck.

 

[bplech]

jec67
Eventually I set up this problem on RISA 3d usnig Links. The stress in the steel beam is 17.7 ksi and the stress in the timber beam is .85 ksi. the moment to the steel beam is 49.1 k-ft and the moment to the wood beam is 15.7 k-ft. After the initial beams are laid out on the computer program I solved for five othe beam laoding and beam lengths variations very easily. thankyou for helping.