Finite element analysis (FEA) gives engineers an incredibly powerful way to predict how a component, structure or machine will perform before it ever reaches the field. Engineers can evaluate stresses, identify potential failure points and compare design alternatives virtually, often saving considerable development time and expense.
But even the most sophisticated simulation has a fundamental limitation: It can only analyze the conditions it has been given. If the loads, boundary conditions and operating assumptions going into the model don’t accurately represent what a product experiences in the real world, the results may not accurately represent its performance either. At 6D Testing & Analysis, that’s why we often approach physical testing and simulation as complementary tools rather than separate disciplines.
The Challenge of Knowing the Real Load
One of the most important questions in structural analysis is also one of the most difficult to answer: What loads is the product actually experiencing? Consider a piece of mobile equipment operating on a construction site. Engineers may know its weight, rated capacity and intended operating conditions. What’s harder to predict are the dynamic loads generated when the machine travels over uneven terrain, encounters an obstacle, handles an unbalanced load or is operated differently than anticipated. Those real-world events can create forces and stresses that aren’t obvious from specifications or design assumptions alone.
This is where field testing becomes particularly valuable. By instrumenting equipment with strain gauges, accelerometers, load cells, pressure sensors and other measurement technologies, engineers can capture what a machine or component experiences during actual operation.
Instead of asking, “What do we think the load is?” the engineering team can begin with a much better question: “What did we actually measure?”
Connecting Testing and Simulation
Physical testing and simulation are sometimes viewed as alternative ways to answer the same engineering question. In our experience, they’re often most powerful when used together. FEA can help identify where stresses are likely to occur, which load cases deserve additional attention and where instrumentation should be placed during testing. Physical testing can then determine whether those analytical predictions correspond with actual behavior.
And when the two don’t agree, that’s not necessarily a bad result. A discrepancy can tell engineers something important. Perhaps the actual loads are different than expected. A boundary condition may not accurately represent the physical structure. Material properties may need refinement. Or the machine may be experiencing an operating condition that wasn’t considered in the original analysis.
Measured data allows engineers to refine those assumptions and rerun the analysis. This process of correlating physical results with simulation helps build confidence that the analytical model represents what’s really happening.
Finding the Cause of Real-World Failures
This combination becomes especially valuable when troubleshooting equipment that isn’t performing as expected. Suppose an FEA model indicates that a component should withstand its design loads, yet cracks continue to appear in service. Simply rerunning the same analysis may not reveal the answer because the problem could be an operating condition that wasn’t included in the original model.
That’s when it may be necessary to go to the machine. By instrumenting the equipment and measuring loads, strain, vibration and other parameters during actual operation, engineers can identify events that weren’t previously understood. Those conditions can then be recreated in the analytical model to investigate why the failure is occurring and evaluate potential solutions. Rather than relying on trial and error, the engineering team can use measured evidence to guide the investigation.
Turning Today’s Field Data Into Tomorrow’s Better Design
The value of field data doesn’t end when a particular problem has been solved. Measurements collected from existing equipment can help engineers establish more realistic design requirements and load cases for future products. Over time, this creates a valuable body of engineering knowledge about how machines actually behave, not just how they were expected to behave.
Simulation provides tremendous insight into product performance, but its value depends heavily on the quality of the information behind it. By combining real-world measurement with analytical modeling, engineers can close the gap between assumptions and actual operating conditions. And that can lead to better models, better troubleshooting and, ultimately, better products.
Put Real-World Data Behind Your Engineering Decisions
Whether you’re validating a new design, investigating an unexpected failure or trying to better understand the loads your equipment experiences in service, 6D Testing & Analysis can help connect what happens in the field with what happens in the model.
Talk with the 6D team about how field testing, data acquisition and FEA can help you understand your equipment and make your next engineering decision with greater confidence.