Thermal behavior of hollow and solid steel beamswith different boundary conditions

The thermal behavior of hollow steel structural members due to the temperature increasehas not been investigated and discussed in many design codes. This work presents a studyof the hollow and solid steel beams’ carrying capacity under elevated temperatures. Thematerial properties of such beams decline under the temperature expected to increasethe moments on the beams. The finite difference technique is selected first to analyze theproblem. The solved problems cover beams under concentrated point load levels with dif-ferent end conditions such as cantilever, pin roller, and both ends fixed. The beam response(deflection, bending moment, and normal force) is examined. The finite element analysiswas conducted using the DIANA FEA software to study the same problem incorporatingmaterial and geometric nonlinearities. It was found that both finite difference and finiteelement analysis solved the problem accurately when the temperature was under 500C.It was also found that when the temperature was applied to the beam bottom face thedeflection was smaller than when the temperature was applied to the side faces only andthe whole section.