Virtual Testing: Use of Computer Simulation for Better Products By Christopher J. Brand, P.E.

Physical testing can be costly and time consuming in the product development process. Physical prototypes need to be created, then the test hardware needs to be procured, data logging needs to be setup, etc. Furthermore, the tests may not yield expected or desirable results thus necessitating the proverbial “back to the drawing board.” This holds true whether one is testing a product like an entire automobile or just a component of that vehicle’s suspension. Therefore, reducing the number of testing iterations is obviously desirable.

One way to reduce the number of steps in this iterative process is “Virtual Testing” or engineering simulation. Computer simulation software, such as Finite Element Analysis (FEA) or Computational Fluid Dynamics (CFD), is widely used in the industry to perform virtual mechanical tests. Using a 3D CAD model of a particular component or assembly, mechanical loads (e.g., forces, heat, wind) are applied and results are computed. These results give you deeper insight into the performance of your products than physical testing alone. Furthermore, test parameters can be changed and run easily, thus reducing the expensive investment of time and money for additional prototypes and testing. 

A leak from a propane cylinder is modeled using computational fluid dynamics.

A leak from a propane cylinder is modeled using computational fluid dynamics.

Due to performance improvements in computer software and hardware, performing simulations are as valuable as ever. Simulations are no longer restrained to single components with limited mesh resolution that need to be run on UNIX stations. These simulations can include full assemblies with complex interactions.

The types of simulations have also become broader. For example, impact tests from falling objects can be simulated and do not necessarily require explicit-dynamic analyses. Evaluation of bolted connections is another example. Two bolted connection designs may seem comparable but further analysis can reveal a critical difference that would be difficult to test. Thermal and fluid dynamics tests have particularly gotten more valuable in recent years. For example, a fire test which involves temperatures exceeding 1,000°C (1,830°F) can be simulated to evaluate the temperature and thus strength of a structural component.

Another example is ventilation in an air conditioning system. The fluid mechanics and heat transfer can be simulated to evaluate the comfort level of the occupant. These results and information can help the product engineer make physical tests smarter and more efficient.

On January 24, 2018, Crane Engineering will be presenting this topic in greater detail at the Crane Engineering Smart Sessions.  Please RSVP for this free continuing education and networking event.

 A fractured patio chair is modeled using finite element analysis

 A fractured patio chair is modeled using finite element analysis