Setting up excavators with growing cracks in their metal structures for repairs

[摘要] When determining the loads that arise on the working bodies of excavators, it is assumed that the developed soils and blown rock are homogeneous and are cut by a bucket in the form of shavings of a certain thickness. At the same time, it is considered that in metal structures of excavators there are no stress jumps from the bucket collision with individual pieces of rock, and cyclic loads are related only to the loading and unloading cycle of the bucket. Studies have shown that in cyclic loading of metal structures, the bucket collides with each piece of rock. The magnitude of voltage jump depends on the size of rock piece. Presently, theoretical calculation of stresses in metal structures of excavators is carried out without taking into account the concentration of stresses in zones of welding defects and this gives underestimated stresses. Studies have also shown that in zones with defects, the stresses can differ several times from nominal stresses.

[发布机构] Saint-Petersburg Mining University, 21 Line, No.2, Saint-Petersburg; 199106, Russia^1

[效力级别] 电工学

[关键词] Growing cracks;Loading and unloading;Metal structures;Nominal stress;Stress jumps;Theoretical calculations;Welding defects;Working body