simple question

huangyhg

simple question
hi all,
i hope i am in the right place to ask this question,i have a simply suppoted beam which has got a inclined load acting on it,i have trying to calculate the bending stress and shear stress acting on the beam,the problem comes comes here
the bending stress is way above the allowbale and the shear stress seems to be less than the allowable stress.
i know its one of the basic question,but still i am not sure is this correct
regards
badri07.


i am not sure if i understand?  what exactly is your question?  why is your beam failing in bending and not shear?
long beams with 'lighter' loads will tend to be governed by bending.  short beams with 'high' loads will tend to be governed by shear.
however, you haven't actually provided any information about your actual situation so it is impossible to say.
and don't forget to check deflection as it also can control in longer spans.  
if this is a wide-flange, this is quite common. wide flanges are typically way over-designed for shear. so much so, that engineers don't even really check it for shear for regularly-loaded beams.
if the bending stress is way above the limit then size it higher.  and check deflection!
never, but never question engineer's judgement
base your design on bending capacity and then check for deflection and adjust size accordingly.
shear rarely governs for steel beams unless it is short with very high loads.
i say bending capacity not stress as you need to check your flexural torsional buckling also.
you will also have an axial load from the component of the inclined load which will need to be checked in combination with the bending.
hi all,
thank you for all your time and  post,yes when you have the beam as simply supported i would like to know what is the effect the horizontal component (along the beam) is going to have on the stablity of the beam.infact the beam is 1.8m in length.
the cross section of the beam i am using is 356x268x129.
thanks
regards
badri07

badri,
you need to design it to the steel code or get a structural engineer to do it for you.
good luck.