The maximum deflection of a 20.5ft C3x5 steel channel with a point load of 921.86lbs at the center can be calculated using the formula PL^3/192EI, resulting in approximately 1.5 inches of deflection. The moment of inertia is 1.86 in^4, and the modulus of elasticity (E) is 30,000,000 psi. If the beam is simply supported, the deflection increases fourfold, and the stresses double, raising concerns about the beam's suitability for the load without proper lateral support to prevent flange buckling.
PREREQUISITESCivil engineers, structural designers, and anyone involved in the analysis and design of steel beam structures will benefit from this discussion.
if the beam is truly fixed against rotation at both ends, max deflection occurs at midpoint and is equal to PL^3/192EI , or near an inch and a half for your load and beam length and size. But, you have to be careful using long channels because stresses may be excessive if the beam is not laterally supported against local flange buckling, and loading not at the shear center causes additional torsional and warping stresses. If the beam is simply supported, stresses double and deflection increases fourfold. Seems like a very flimsy channel to use for this loading. Allowable stress is a great concern.blake92 said:i have a 20.5ft c3x5 steel channel with a point load at the exact center and i wanted to determine its maximum deflection.
the point load is 921.86lbs, and moment of inertia is 1.86in^4.
modulus of E= 30,000,000psi