Failure analysis of frame crack on a wide-body mining dump truck

• The failure and subsequent analysis and modification of a WMDT frame is discussed.
• The interaction between the frame and leaf spring plays an important role in frame cracking.
• FEA and static-dynamic tests are used to find the reasons for crack and design improvements.
• The service life is extended from 5 months to more than 12 months.

The wide-body mining dump truck is a type of heavy-duty, off-highway truck that is mainly used for transporting rock and ore in open-pit mines. Because of various potholes, obstacles, slopes and curves on the bumpy road, the frame of the truck is impacted by the multiform large loads from ground. After five to six months in service, cracks tend to appear in the frame of the truck, near the rear seating of the front leaf springs. To identify the cause of these failures and propose an approach for improving the design, a practical method combined with finite element analysis (FEA), as well as static and dynamic testing, was applied. FEA was used to analyze the cause of the cracking, after which the design of the frame was improved. Static and dynamic tests were conducted to verify the FEA results of the improved frame. Analysis results indicated that the stresses are concentrated in the frame near the rear seating of the front leaf springs, which results in the premature appearance of fatigue cracks. A solution for preventing the appearance of these cracks was proposed. The improved frame has been in service for more than twelve months in the mine and no cracks have appeared to date.