In my previous blog, I discussed the benefits of FEA in validating designs. When a failure has occurred in the field, manufacturers want to understand why the part failed before replacing a machine that may likely just fail again. That’s where FEA can be used to aid in failure analysis. We can use FEA to re-create the conditions that caused the break and help design a fix to the machine.
In this example, a piece of construction equipment has snapped a structural member. Metallurgical reports state that the failed part’s material is within specifications and a physical inspection of the part shows fatigue was the cause of the break. The manufacturer then contacts STS Technical Services to perform an analysis of the failure mode.
The first thing we’ll request is as much information about the failure mode as possible; things like position of the machine, load rating for the machine and pictures of the failed machine. With an idea of the failure mode, we can start re-creating the situation in CAD. This can often require numerous iterations of FEA, like checking different loading, grounding, and position options. Our goal is to find scenario that proves the physical failure.
Once we have an accurate FEA, we start designing a solution to the failure state. Working with the manufacturer, we determine what kind of fix they want produced. Depending on the number of machines in the field and how the parts are made, it can make more sense to send replacement parts (perhaps with a beefier cross-section or a stronger material) or create a retrofit kit for the existing machine (a bolt-on or weld-on stiffener to the original parts). With our failure FEA, we are able to check any modifications quickly to see if they solve the issue that caused the failure.
After we have solved the initial failure, we will study the remainder of the machine and determine that no other components are impacted by the proposed fix. We can also perform other studies to help confirm the fixed machine will survive its projected lifetime; tests like studies on bearings and motors, performing bolted joint studies and fatigue analysis.
To learn more, please give our team a call right now at 1-800-447-0515. Alternatively, more information can be found online at: www.sts-ts.com