We performed a site review of the car body and obtained key measurements to inform the analysis model. Based on the information available, we devised a nominal loading regime, assessed the fatigue life, and identified regions of lowest fatigue life.

Our final report included modifications proposed to the car body to improve fatigue life and protect the car body structure following the repair of the cracks

Scope Of Work

• Site visit to inspect the cracking and obtain dimensional data not available. Establish the loading regime of the shovel.
• Determine loading from the masses and load data provided.
• Prepare a finite element analysis model to assess the stresses. The FEA included the already removed welded attachments and determined the stress that resulted in the failures. Revised FEA included the modifications required to restore the structural integrity of the undercarriage.
• Prepare a repair scope

Project Challenges

Inspection limited to parts of the car body that were accessible. Review of the internal structure and condition of the car body was not possible.

How We Managed This

• CAD model of the car body based on photos and published data for the CAT 6060 shovel.
• Although the car body is geometrically symmetric, a full model was developed due to asymmetry in the applied loads.
• Some regions of the model needed greater detail than normally required, and were modelled using solid models. This included the problem attachments to the car body.
• Calculated fatigue life contours corresponded with the known crack initiation location, validating the fatigue analysis methodology and representative load cycle selected.

Value Engineering

We designed the repairs based on our analysis and then detailed them for the Client.