Crane manufacturers analyze: What are the reasons for cracks at the welding joints of cranes?

Crane joints at the connection of the beam and main girder, as well as between the upper beam and the support legs, and at the welds, may develop cracks. Some load-bearing areas not only endure bending and shearing forces from the weight of the load and the structure itself, but also lateral forces due to inertia or wind. This results in a significant composite force and varying force directions, leading to fatigue failure and the formation of cracks.

To reduce cracking during the operation of electric hoist gantry cranes, a rational reinforcement device can be designed in the main beam. A transverse plate consistent with the main beam can be added at the connection point between the web and the main beam, and it can be welded to the main beam of the electric hoist gantry crane using the flanges of the I-beam. Additionally, a longitudinal horizontal plate can be added at the welding points between the upper and lower covers of the beam and the main beam of the electric hoist gantry crane.

3. By setting the horizontal plates, the overall rigidity at the connection between the beam and the main girder can be significantly improved, as well as the local stability of that section. This effectively resolves stress concentration issues, thus preventing localized fatigue failure and the formation of cracks. In addition to adding stiffeners, reasonable transition angles can be set for gradual transitions and a rational overhead girder structure can be established. Selecting the appropriate model based on the actual project conditions is also an effective method to reduce the number of cracks in electric hoist gantry cranes.