Move test data up front in design

Real-world component test data can be used to calibrate dynamic simulation early in product development, says Tom Curry of LMS.

Design News: Why would an engineer want to use real-world test data to calibrate dynamic simulation?

Curry: Calibrating the computer analysis model using the known behavior of mechanical parts eliminates unnecessary simulation, guesswork, and the risk of overlooking important performance parameters that could affect the accuracy of the analysis.

Q: How is test data combined and coordinated in the simulation?

A: Test data and dynamic analysis are coupled through embedded data management capabilities that correlate the two types of data into a single virtual prototype, in an approach we call hybrid simulation. Software supporting the approach was specifically developed to store, access, and reuse test data for this process. Also available for use in facilitating hybrid simulation are web-based information-sharing tools that enable engineers, managers, technicians, and others to share test and simulation data on an enterprise-wide basis between distributed groups, global facilities, and subcontractors throughout the supply chain and extended enterprise.

Q: How does hybrid simulation differ from what's done in traditional virtual prototyping?

A: Hybrid simulation represents a step beyond conventional virtual prototyping systems that attempt to simulate the entire mechanical system using analysis only. The problem with such simulate-everything systems is that engineers have to speculate on how complex variables will play out in the actual product. Often, unexpected problems go undetected until physical prototypes are built and parts break, or worse yet, when a product fails after it's manufactured and sold. By then, the cost of changing designs and fixing problems becomes astronomical. In contrast, hybrid simulation leads to fewer but better hardware prototypes by ensuring that quality is designed into the product. This shifts the balance of engineering activity from troubleshooting during prototype testing to analysis early in the conceptual stages of design.

Q: What types of variables does physical testing provide?

A: There are a wide range of physical tests available for mechanical systems. Most fall into the broad categories of structural integrity, vibration, noise, and durability. These are the variables used extensively in automotive, aerospace, defense, and other advanced manufacturing industries. In the automotive industry, for example, durability analysis predicts the fatigue life of parts such as shock absorbers.

Q: How does this work in practice?

A: Using hybrid simulation, an automotive engineer can modify the shape or stiffness of an engine mount, for example, obtain the new force inputs, and from there listen to the sounds that would be heard by a driver as the engine accelerates. The modeling process makes no distinction whether the data is generated from test, from finite-element analysis or synthesized from a multibody dynamics simulation.

Q: What's on the horizon?

A: We are rolling out tools for engine development teams that integrate test and virtual prototyping processes. The CAE tools include multibody dynamics, noise and vibration, durability and optimization. These tools provide a multi-disciplinary approach to the engineering process that in the past would have required the use of disparate tools from a variety of vendors. We are developing an integrated suite of multi-physics software that will allow results from a multibody dynamic simulation to be used as inputs for acoustic and durability prediction.

Tom Curry Vice President, Board Member LMS International Leuven, Belgium

Tom Curry has been in mechanical design automation for over 25 years, first in automating a major petrochemical company design department (1975-80, Air Products & Chemicals), as a marketing director for CAD pioneer Autotrol, as vice president of marketing for McDonnell Douglas Unigraphics, as president of PDA, and as president and CEO of MacNeal Schwendler (now MSC Software). He is a licensed professional engineer and holds a bachelor's degree, cum laude, in civil engineering from Rutgers University in New Jersey.