Scientific paper ID 2169 : 2021/4

The load-bearing structures of the lifting and transporting machines are subjected to different loads and sizes of loads, which can be grouped as follows: weight, dynamic, meteorological and special.

When inspecting metal structures, it should be borne in mind that fatigue cracks occur mainly in the areas of local stress concentrators, namely: mounting points for brackets, racks, elements with a sharp difference in cross sections, places for termination of overlaps, ribs, areas of holes with untreated, burnt or welded edges, welding intersections, places of repeated welding of cracks in welded seams, etc.

If mechanical damage to a metal structure is found (dents, bends, fractures, etc.), their dimensions (length, width, height or depth) are measured. The damage dimensions must then be compared with the limit dimensions of a similar defect for the metal structure of a crane of this type and, if the standard values are exceeded, the damage must be recorded in the defect list and appropriate remedial action taken them.

The article analyzes the possibilities for safe operation of metal crane structures.