Fatigue Assessment of Steel Structures Under Dynamic Loading

This paper on "Fatigue Assessment of Steel Structures Under Dynamic Loading" was presented at the NAFEMS World Congress on The Evolution of Product Simulation From Established Methods to Virtual Testing & Prototyping - 24-28 April 2001, The Grand Hotel, Lake Como, Italy.

Abstract

The starting point for the work carried out was the damage analysis of a screening machine in operation. This machine is designed for splitting the coal into different grain sizes by shaking them over perforated plates with graded hole diameters. It is supplied upon largely dimensioned rubber blocks. On the top of the steel structure the motor, gearbox and the eccentricity-shaker is located. The rest is constructed as a welded and bolted steel construction. By observation some defects were monitored by perpetual inspection of the carrying girders and profiles. In summary three weaknesses were discovered where the origin of these were not quite clear to the user nor the constructors. For this purpose an eigenvalue analysis was performed on the steel structure of the screening machine. At least 16 different eigenvalues were found which might have caused the problems mentioned above but not all of them could be considered in the subsequent fatigue assessment.