Fatigue failure analysis of steel crane beams with variable-section supports

The service safety problem of steel crane beams in metallurgical industrial buildings has been attracting increasing attention recently. The fatigue failure problem of the steel crane beam with variable-section supports becomes particularly severe. Therefore, the present study focuses on exploring the reason for such fatigue failure in terms of the design method, actual service load, and reliability of existing structural components of the steel crane beams. First, the study clarifies the "Z class" of various variable-section supports based on fracture mechanics theory to design fatigue strength parameters for steel crane beams. Then, it explores the indeterminant design parameters of fatigue load through numerous load tests and analyses, discussing the applicability of current approaches on selecting appropriate parameters. At last, this paper carries out a statistical analysis of fatigue reliability of existing steel crane beams with variable-section supports. This study concludes the main reasons for frequent fatigue failures of steel crane beams with variable-section supports, which provides a basis for solving such fatigue failure problems in practice.