We all know that using physical testing to validate products is a risky maneuver. This sample project highlights exactly why that is!
Problem Statement
Fidelis was contacted over a year ago by a defense contractor wanting to validate the design of an electronics bay exposed to significant shock loading prior to physical testing. After the quoting phase was complete, the customer decided to take the physical testing route instead of utilizing simulation, which involved developing a finalized design, purchasing molds, creating prototypes and enlisting a physical testing company to carry out the work…
Fast forward one year and the customer came back to Fidelis – the testing had failed, the part was damaged during the process and now they were back to square one with the design.
Methodology
Since Fidelis already understood the problem, we were able to get to work immediately, developing a high-fidelity mesh and taking advantage of a shock response spectrum (SRS) type linear dynamic analysis to assess the baseline part. As expected, the results of the analysis correlated extremely well with the failing physical testing already carried out, and this provided confidence in the model and analysis type selected.
Next it was time to improve the design based on the customer’s stringent guidelines of what was allowable. A number of design parameters, including the filet sizes at the key stress concentrators and the thickness of the overall chassis, were investigated by way of formal design of experiment (DOE). Results of all options were presented to the customer over the course of around one week.
Results and Conclusions – Our Value
I think it’s safe to say that the customer would’ve benefited from taking advantage of simulation in the first place. In the end, we were able to provide three options for passing designs that allowed them to select the preferred manufacturing changes for their product. Essentially, we took the pain and stress of one year of work and likely tens of thousands of dollars in prototyping costs and presented passing designs within a week. If this doesn’t convince you that virtual product development is the way forward, I’m not sure what would!
TL;DR
Fidelis was able to take a failing design and, with the use of linear dynamic shock analysis, present the customer with a number of options to fix it. This was after a significant outlay in physical prototyping that could’ve been completely avoided had virtual product testing been completed during the design phase of the program.
