Virtual testing is what those that perform simulation do every day. Through the use of computer aided engineering (CAE) tools, engineers create virtual experiments that complement physical tests. The advantage of virtual tests is that they can often be performed more quickly and cost effectively than physical lab testing to provide information that guides design decisions. This is especially valuable in the early stages of product development.
The physical test process is an almost perfect analogy for the virtual testing process. The terminology may be different, but the inputs, outputs, and overall concepts are nearly identical.
Figure 1 – The Test Process
Whether one is performing a physical or virtual test, the Plan Phase starts the process to define the scope of the work to be done, items to be tested, performance requirements to be achieved, test methods to be used, and resources needed. These form the major elements of the test plan.
Items to be tested are prepared in the Build Phase. In physical testing, items may need to be purchased or fabricated. The analogous activity in virtual testing is known as modeling. In this step, the virtual items to be tested are constructed according to the needs of the test to be performed. These items may include spreadsheets, finite element models, boundary element models, computational fluid dynamics grids, and mechanical systems models. These simulation models can be derived from CAD models, previous CAE models, or made “from scratch”.
Once the items are fabricated or models are ready, they need to be placed into the environment that represents their “real-world” use for testing. Instrumentation that gives precise measurements of quantities of interest at specific places on the part or assembly may need to be added. The Instrument Phase may add displacement probes, strain gauges, accelerometers, and cameras to physically or virtually measure product performance.
After being built, placed in the test environment, and instrumented for data collection – we’re ready to run the test in the Execute Phase. Items are ready for physical testing or we have a “run ready” virtual model that can be sent to a computational solver.
The Execute Phase is the stage where the experiment is run and data is gathered. In the virtual world this may also be known as “running the job”. The result of running the virtual or physical test can be volumes of output data that will need further processing to convert the numbers into engineering information used to make design decisions.
The Analyze Data Phase is the activity in which data reduction and visualization is used to comprehend product behavior. Sophisticated algorithms might be used convert raw physical test measurements into useful engineering data. The same algorithms may be used on the virtual test results so that physical and virtual models can be correlated. Plots, graphs, movies, and other visualizations created in this phase give meaning to the data so that it can be used for decision making. Key results that map to target requirements can get fed back to into a requirements management system, providing the answers the questions.
The Report Phase documents the relevant facts and conclusions for communicating what was done for others and for future reference.
The project Close Phase is similar between physical and virtual testing with one major difference. The test items of a physical test are likely to be discarded since the test items may get destroyed or otherwise rendered useless. However, virtual test models are reusable. They can be modified and adapted to perform additional experiments.
Figure 2 – Physical and Virtual Test Processes
One can see that the physical test process and the virtual test process are nearly identical. However, they also share common challenges.
- How does one find completed test reports?
- What was the product configuration tested?
- What test methods and procedures were used?
- How can one locate a model for re-use?
- Which tests have parts with a specific material of interest?
- Which designs met target requirements?
- Which tests are in a particular stage of the testing process?
In order to effectively answer these and hundreds more questions that arise, the processes and related data needs to be managed.
Virtual Build & Test Management is the discipline of getting simulation activities completed efficiently and effectively, gaining the best return on all resources. It differs from product lifecycle management (PLM) solutions that claim to be all things to all people, Virtual Build & Test Management is focused on managing all aspects of doing simulation – not just controlling simulation work products and their approval.
I’d like to know what you think about this. What are the barriers you face in implementing a managed simulation environment? What do you need to get out of it?
You can poke around our website to learn more about SimManager or drop me an email at firstname.lastname@example.org. I’d be happy to learn about what you’re doing today and figure out if there’s a way for MSC to help.