By Bruce Jenkins, President, Ora Research
Simulation apps are the latest development in making advanced CAE capabilities safely and easily available to engineers and designers. As we explored last month (New frontiers in simulation process automation), simulation apps provide sophisticated functionality packaged as easy-to-use, tightly focused apps that automate the design, analysis and verification of a specific type of product, often tailored to the needs and best practices of a specific user company. First the company’s engineering knowledge is captured as rules in a set of templates that automate the design of the targeted class of product. Then, in use, the templates call on general-purpose simulation and analysis software to drive automated CAE model preparation, physics calculations in the various disciplines involved, and presentation of results in the form of an optimized, validated design.
One company putting this new approach into practice is BWAY Corporation, one of the largest manufacturers of rigid metal and plastic packaging containers for industrial, commercial and retail markets in North America. In a recent webcast hosted by the CAE professional association NAFEMS, BWAY’s Engineering Manager for Plastics, Forrest Burney, described how the company is using simulation apps to save project costs and shrink time-to-market for new products, as well as to gain more control over the design process by no longer needing to rely on outside CAE service providers. Furthermore, Burney says, “Because we can analyze more design iterations faster, we can do a better job optimizing the design up front and have a higher confidence level in the performance of the finished package.”
Describing BWAY’s product requirements, Burney notes that packaging should provide the lowest possible cost, maximum performance throughout the distribution chain, and market differentiation by means of container shape, aesthetics and value-add features. In particular, two packaging performance expectations are critical. One is top load strength: the packaging must withstand heavy top loads while stacked in warehouses and distribution centers. The other is impact resistance: packaging must not dent, crack or buckle under normal handling and transportation conditions.
“Cut-and-try” product development process (pre-2005)
Before 2005, BWAY’s product development process was based on engineering “rules of thumb” and what Burney calls “tribal knowledge.” New designs were evaluated by fabricating injection-mold tooling for the design, using the mold to produce sample molded parts, performing physical testing of the molded parts to validate their performance, and evaluating the test data to decide whether the design was ready to go to market, or instead needed to go “back to the drawing board” for refinement. In the latter case, another round of physical prototyping and testing was then required.
The one upside of this approach was that it utilized designers’ available skill sets. But a big downside was cost. Changes to injection mold tooling are expensive, Burney says, noting that each iteration can cost between $5,000 and $40,000. Another downside was long time-to-market. Each tooling iteration takes weeks to complete, sample and test, and multiple iterations are often required to meet performance objectives.
Vended CAE process (2005-2015)
In 2005, to bring simulation and analysis into its product development process, BWAY began working with a third-party CAE service provider. The benefits gained from this approach were the ability to predict structural performance before cutting steel on mold, and a reduction in the number of tooling revisions required as well as in overall project costs.
But this approach still had limitations. The service provider faced a learning curve to understand and develop expertise in BWAY’s products and its particular analysis needs. Time-to-market remained long, because each design iteration or set of iterations had to be communicated to the service provider and received back again; one set of design iterations could take two to three weeks to complete and review. Also, analysis run times were limited by the service provider’s hardware.
Sim-App process (2015+)
In 2015, BWAY moved to address these issues by introducing product-specific, cloud-based simulation apps (Sim-Apps) into its product development process.
This new approach has yielded multiple benefits over the older methods, Burney reports. It lets BWAY engineers predict structural performance before cutting steel on mold. It reduces the number of tooling revisions required. Engineers can now run multiple design iterations quickly — within days, Burney says — and make design decisions in near-real-time. It reduces both overall project cost and time-to-market. Simulation set-up expertise is built into the app. And cloud-based apps can utilize additional computer nodes as needed to speed up analysis times.
Top load analysis Sim-App process
Burney describes the process of using a Sim-App to carry out a top load analysis of a container design. Accessing the cloud-based simulation app over the Web, the user submits a SolidWorks file of the product geometry and inputs the following information about the design: material, compression distance (mm), duration (ms) and mesh size (mm). Then the simulation runs in six to 15 hours, and delivers results in the form of a 3D view of deformation to the container (image and video), maximum reaction force, percentage error, and a force-versus-deflection graph.
Current error in results produced from the simulation app is approximately 15% compared with physical test results, Burney says, and the company is working to improve this to within 10%.
Payback: Lower costs, faster time-to-market, higher confidence in product performance
The figure below shows the reduction in typical product development cost that resulted from adoption of Sim-Apps. Burney explains that pre-2005 costs assume three tooling revisions at $15,000 each, 2005-2015 costs assume two tooling revisions at $10,000 each, and 2015+ costs assume one tooling revision at $5000.
The figure below shows the reduction in time-to-market that resulted from adoption of Sim-Apps. Burney notes that pre-2005 timing assumes three tooling revisions at three weeks each, 2005-2015 timing assumes two tooling revisions at two weeks each and five weeks for multiple CAE iterations, and 2015+ timing assumes one tooling revision at two weeks.
Burney sums up the benefits of Sim-Apps for BWAY: “Simulation apps allow us to submit multiple designs with varied inputs and return to acceptable results the following day. By investing in simulation apps, we can save overall project costs and decrease our time-to-market for new products. We have more control of the design process because we do not need to rely on outside vendors to obtain test results. Because we can analyze more design iterations faster, we can do a better job optimizing the design up front and have a higher confidence level in the performance of the finished package.”