The effect of load misalignment on beams with a height constraint

摘要

Load misalignment is known to reduce the efficiency of structural sections. The study shows that the rate of reduction in efficiency of a section due to misalignment differs depending on the section shape. Sections that are most efficient when loading is perfectly aligned may not be the best choice when there is a load misalignment. When the misalignment is small, i.e. <2°, designers often assume loads are perfectly aligned in order to simplify and minimise design calculations. Safety factors are then used to cope with the effect of misaligned loads. This method is however crude and can lead to over design or under design depending on the section chosen. Therefore, it is necessary to have a simple but an effective methodology to assess the effect of misaligned loads. This paper extends the methodology of shape factors by developing shape factors for geometrically constrained beams with misaligned loads. The paper also shows that a very small misalignment (<2°) can cause significant reduction in efficiency of sections.