Strength and Deformability of Steel Beams with a Step-by-Step Change in Wall Thickness

Statement of the problem. The objective of this work is to study the increase in the efficiency of material use in welded steel I-beams by means of a stepwise change in wall thickness. Results. The stress-strain of two test steel beams with a span of 12 m with a constant and stepped wall thickness was determined numerically and analytically, the strength and deformability of steel beams in three characteristic sections were assessed. A comparison of the results of analytical and numerical calculations of the test steel beams shows that a stepwise decrease in the thickness in the middle section of the wall has virtually no effect on the strength and rigidity of the beam element in the middle of the span, but significantly reduces the shear strength in the support sections and increases the length of the area of tangential stress concentration in the wall of the support nodes. Conclusions. The obtained results indicate the constructive efficiency of using a step change in wall thickness in solid steel beams. Reducing the thickness in the middle section of the wall in welded beams allows for steel savings with an increase in labor intensity in manufacturing.