Defects of steel crane beams and methods of their strengthening

Abstract

Crane structures are the most vulnerable in buildings and structures because of their early wear in comparison with other building structures. The wear of crane structures is because of the appearance and the development of fatigue damage nature. The article presents the constructive solutions developed by the authors for strengthening the structures of steel crane beams with conventional and corrugated walls which allow to reduce the influence of the negative influence of installation, operation and technological processes on their operational durability. The most dangerous installation defect is the displacement of the crane rail axis relative to the axis of the crane beams wall. Value of this shift is exceeded several times in the cases considered below. It is proposed to use crane beams with corrugated walls to solve this problem. The authors have developed and implemented a project to restore the performance of steel crane beams by strengthening the walls of damaged beams without stopping production. Strengthening was performed on the outside of the eccentricities of the application of loads from crane rails by creating a truss structure parallel to the I-beam with chords of I-beams, which made it possible to significantly reduce the magnitude of local stresses from moments, the magnitude of transverse forces and consequently shear stresses, which are the main factors in the appearance and development of fatigue cracks in their walls.

Non-disruptive method to decrease stresses in the web of the crane beam

“…A large number of studies are devoted to the issue of reinforcement of the crane beams [7][8][9], as well as the analysis of the residual life of existing crane beams with cracks [10,11] in order to predict the remaining service life of such beams.…”

Вплив Легування Металевої Матриці На Антифрикційні Властивості Евтектичних Покриттів

“…Перспективним шляхом покращення антифрикційних властивостей сплавів може бути легування їх металевої матриці. У литих евтектичних сплавах на основі перехідних металів з тугоплавкими фазами втілення, унаслідок малої взаємної розчинності, практично, поєднуються вихідні властивості фаз, що утворюють її [2]. Фази втілення мають високу температуру плавлення, твердість, міцність, пружність, хімічну та термодинамічну стійкість і зносостійкість.…”