Advancements in engineering software development have played a major role in the redefinition of engineering processes and organizational structures. For many companies, the acquisition of new software technology often stimulates a rethinking of their overall design process, with the reward being an increased competitive advantage. As a result, implementing new software technology can impact the role and effectiveness of the engineer.

This impact has been evidenced by the incorporation of the finite element analysis (FEA) method into the product design and analysis process and the even more recent trend to promote its use earlier in the design cycle. The potential benefits of this process change, such as increased quality and design cycle reduction, have been obvious to many since the introduction of FEA on personal computers. 

The proper implementation of FEA as a tool typically results in a marginal shift in how designers, engineers, analysts, prototype testers and others spend time on a project. However, due to some inherent limitations of linear static stress analysis, arguably the most prevalent form of FEA currently utilized by engineers, not all classes of problems can be addressed with certainty and therefore, not all roles can be fully optimized. There still remains enormous potential to compress design time even further.

A New Tool

Enter the latest addition to the engineer’s arsenal of software tools, Mechanical Event Simulation (MES), another important technology milestone towards the ultimate goal of accurate, up-front analysis. MES is the culmination of a collaborative research and development venture with a leading university, with the first product release occurring three years ago. This dedicated research effort resulted in a unique combination of the capabilities of kinematics and FEA, where both solid mechanics and Newtonian dynamics are incorporated during the simulation of a mechanical “event.” MES is a complete replacement for conventional FEA, encompassing all aspects of that discipline and extending it into one seamless package with built-in capabilities such as large-scale displacements (e.g., motion), time-dependent loading, surface-to-surface contact and nonlinear material behavior. After all, with the widespread use of plastic and composite materials and the high performance levels (e.g., impact resistance) that customers demand from products, very few analysis situations are either “linear” or “static” in reality.

What all of this means to engineers tasked with stress analysis or failure prediction is that MES can make complex scenarios, previously thought of as too difficult or time-consuming, both practical and more intuitive. The virtual simulation of dynamic events such as impacts, drop tests, crash tests, and reciprocating mechanism assemblies all become possible. Because MES also provides enhanced visualization, such as animations, of these types of real-world behavior, the engineer can more effectively communicate the product’s performance in the actual environment to others in the design process, thereby promoting the practice of concurrent engineering. The use of MES allows the engineer to focus on the fundamental “physics” of the problem, rather than non-intuitive procedures or complicated loads and boundary conditions as is required by traditional FEA.

Streamlined Simulation

Through the constant monitoring of the “physics” of an event, MES computes the loads and dynamic responses resulting from changes in motion using a “state-of-the-art” implicit solver. Alternate event simulators are based on explicit solvers, which are generally impractical when modeling large-scale motion. Thus, these simulators may be impractical when attempting to further compress the design cycle. The computational efficiency of MES is further improved by its use of an automatic time-stepping method. This method ensures that the ongoing “physics” of the event are captured: small steps are taken during critical times, otherwise, larger, more computationally efficient, time steps are taken.

Dynamic loads, which are vital inputs to many analyses, previously required separate software packages, specialists, or actual lab testing. The use of separate software packages, which may contain inherent inaccuracies, typically requires transfer of data and knowledge of different interfaces. In the case of mechanisms, pure kinematic analysis applications may generate results based on the assumption of rigid body motion. In reality, these bodies are not infinitely rigid, but rather have a finite amount of elasticity based on geometry and material properties, which MES can take into account. Specialists employing complex calculations are usually forced to make some assumptions, which may lead to undesirable deviations in accuracy. The accuracy of laboratory or field-testing, performed properly, is unquestionable. However, this testing tends to be cost prohibitive both in terms of setup time and how late it occurs in the typical design process. For example, in the case of plastic parts or metal castings, it is a major project setback when an expensive mold is CNC-machined to create a prototype only to determine that the product fails to meet established design criteria during the initial testing phase.

Mechanical Event Simulation (MES) may compress the typical design cycle shown above by not only minimizing downstream prototyping and testing associated with standard linear static stress analysis, but also by promoting the practice of concurrent engineering.

In summary, the power of MES is that with a single model, complex simulations can be performed using an intuitive approach within a virtual environment on the engineer’s desktop, while maintaining the same level of accuracy as physical testing. The future of computer-aided engineering lies in this ability to accurately portray a product’s intended behavior through the integration of motion simulation, stress analysis and multiphysics analysis. 

Organizational Impact

As a result of the benefits of this emerging software technology, the expectation is that there is even greater potential than standard FEA for not only reducing the design cycle, but also improving product quality since “what-if?” scenarios can be handled more efficiently. The implementation of MES can be another opportunity for companies to reevaluate and further streamline their product development process. Everyone from individual consulting firms to global organizations can benefit to varying degrees from this new technology. For the independent consultant who has to be self-sufficient, less time is spent on estimating loads, so turnaround time can be reduced and more competitive bids can be submitted to clients. Small firms may be able to reduce their dependency on specialized contractors. Mid-size companies may realize unprecedented levels of collaboration and reductions in prototype testing. Larger organizations may find that dedicated specialists or established departments may no longer serve a primary function in their critical development path. Even universities may need to consider the emphasis placed on physics-related courses in their curriculum to prepare engineers for these advances in software technology. 

The above chart demonstrates that in comparison to a typical FEA process, MES may slightly increase upfront analysis time and yet still reduce the overall design process by minimizing the need for downstream prototyping, advanced analysis and testing.

In today’s marketplace, where first-to-market, collaboration and concurrent engineering are key themes, it is no longer sufficient to passively accept new technology. It will be those companies who seek to understand the full potential of their software investment and adapt their organizations accordingly who will gain the distinct competitive advantage.