Case Study 2 - Weld Analysis and Testing

Analysis and Test Verification of Lifting Lugs and Welded Joints

A structural unit is lifted via four standard deck plates. In doing so, the load path passes through a series of welded joints and structural members.

Verification of the mechanical integrity of the deck plates and welded joints was required for customer sign off.

Classical weld analysis and finite element analysis was carried out to evaluate the stress distributions under a gross “in-service” load of 6.5 tons.

A physical test was also conducted to verify analytical results.

Analytical results for weld stresses were compared to FE simulations for the strip welds and deck plate welds. FEA results were within 10% of classic analytical results and as such deemed satisfactory.

Proposed corner fillet welds were deemed insufficient to withstand loading conditions. Extended fillet welds (and additional weld material in key areas) reduced weld stress below acceptable material limits.

To verify the analytical and FE results a dummy load test structure was designed, fabricated and tested to the proof load. Results were satisfactory and certification was given for the structural integrity of the weld configuration and deck plate arrangement studied.