The Study On The Investigating And Strengthening Of Crack Of The Upper Part Of Welded Steel Crane-girder

Steel crane-girder is one of important members in industrial workshop, but in recent years, it finds that the damage of steel crane-girder in the high-frequency is very popular by the investigation of the use of workshop, and especially the phenomenon of the upper part emerging fatigue crack is more serious.Contra-posing the problem which upper part of steel crane-girder emerges the crack of accurate packing up workshop of the primary mill plant of BaoTou Iron and Steel Company, this paper firstly summarizes the internal and external fatigue crack studying condition of the upper part of welded steel crane-girder at present. And it investigates the appearance condition (including joint, crack, eroding, corrosion, braking pole device rupture, crane-girder's gnawing railway and so on) of the whole crane-girder system on the spot, at the same time, it also actually examines the stress of the beam, chemical ingredient, distortion and railway excursion, etc. through sampling, and based on the actually examined results, it checks and calculates the carrying capacity of crane-girder system. Then, based on the investigating on the spot and the calculated result, it discusses the mechanism of fatigue failure of the upper part of welded steel crane-girder, analyses the reason of steel crane-girder in thehigh-frequency emerging the fatigue crack, institutes the strengthened method of damaged steel crane-girder of accurate packing up workshop of the primary mill plant. Finally, it presents some advice and suggestions for the repairing and strengthening method of fatigue crack of upper part of steel crane-girder in the high-frequency.