Michael L. Bussler
President
Algor, Inc.
Pittsburgh, PA

Today’s mechanical engineers have been made to recognize that the life cycle of a product is not over when it is shipped from the manufacturing floor to distribution or retail centers. With the operational life of the product just beginning at this point, manufacturers find themselves shouldering the responsibility of servicing the product after its sale. Those concerned with the bottom line have placed renewed pressure on mechanical engineers to initially design better, safer parts in order to minimize the resources needed for after-market servicing. At the same time, demands remain for shorter times-to-market at decreased costs.

Fortunately, engineers have a variety of Virtual Product Development (VPD) software tools, including CAD, finite element analysis (FEA) and kinematic and simulation software, to aid them in developing product designs from conception to production. Engineers spend less time and resources building fewer physical prototypes because these tools enable engineering by virtual trial and error. Engineers can learn about product design behavior using a computer. However, only the integration of VPD tools into a single What-You-See-Is-What-You-Get environment will enable an engineer to fully understand dynamic mechanical systems within shorter time frames and eliminate the need for physical prototyping.

Engineering within the Product Life Cycle

The life cycle of a product from an engineering standpoint consists of the following major stages:

• Conception of the product idea. 
• Creation of a mechanical design.
• Verification of the design through analysis and prototype testing.
• Manufacturing of the product.
• Servicing of the product after its sale.

Existing VPD software tools each offer different advantages within the individual stages of the product life cycle. CAD software helps with mechanical design by representing components and assemblies visually. During the verification stage, FEA software is useful for calculating stresses, usually at a single instant in time, provided that the engineer can make good assumptions about forces and boundary conditions and knows how to interpret the results. Kinematic software represents motion in mechanisms, and when coupled with kinetic software, yields forces at each instant in time, assuming product components are rigid. Kinematic software often is used in conjunction with FEA software to verify a mechanical design.

In the last few years, interfacing between these software packages has enabled engineers to use two or more packages together, a CAD system with FEA software, for instance. However, only the increased integration of VPD tools-- the harnessing of functions from multiple packages into a single package-- will enable engineers to conceive, create and verify a product design with one seamless process. The development of increased integration will reduce the need to interface multiple software packages, eliminating the inefficiency inherent in transferring data during the creation and verification stages of the product life cycle. The engineer will be spared the effort now spent on repeatedly feeding back results between different packages.

Integrating VPD Tools for Shorter Design Cycles

Algor’s Mechanical Event Simulation software takes a large step toward the integration of VPD software tools by expanding upon traditional stand-alone kinematic and FEA software for solid models and assemblies that originate from CAD systems. Mechanical Event Simulation combines the capabilities to replicate motion (kinematics), dynamic loading (kinetics) and flexing (stresses) of parts of an assembly of interconnected components (mechanisms) during a virtual "event." By combining stress analysis with dynamics (kinematics and kinetics), the integration of VPD tools eliminates the difficulty of manipulating stand-alone solutions and errors that can result when transferring data between packages.

Within the product life cycle, an integrated software tool, such as Mechanical Event Simulation, can be used to transition between each of the first three stages. During the conception phase, an engineer first can construct an entirely kinematic model using Algor’s unique kinematic elements to assess the kinematic functionality of the design without investing an excessive amount of processing time. Kinematic elements can drastically reduce run times because they behave dynamically like regular, flexible elements, but do not produce stresses. Therefore, these elements enable engineers to quickly modify initial designs to ensure a solid design concept before constructing the mechanical design.

During the mechanical design stage, the engineer can create a detailed FEA model based on the initial kinematic model using Algor’s software or build a CAD solid model using a popular CAD system. With one universal product, Algor software plugs directly into the CAD system interface, providing toolbars that complement those available with the host CAD system. Unlike many CAD-to-FEA plug-in interfaces, Algor’s entire line of modeling, mesh enhancement and FEA software tools are available through this plug-in connection.

Finally, the engineer can verify the design by expanding the initial kinematic event into a full Mechanical Event Simulation to replicate simultaneously motion, dynamic loading and flexing of the event on a computer as it may occur in the real world. This single What-You-See-Is-What-You-Get environment lets engineers examine the behavior of the entire mechanical system-- bending, twisting, stretching, squashing and buckling-- without physically building a prototype. Mechanical Event Simulation enables engineers to create only one model and work in only one analysis package to develop a product concept, create a mechanical design and verify the design for manufacture.

Expanding VPD Capabilities to Replace Physical Prototyping

In the future, VPD software tools will offer a wider range of physical phenomena. Stress caused by motion is not the only way that failure can occur. Pressures, significant temperature gradients of the flow of fluids, such as water or air, against an object also can induce forces, which can result in motion and stress. VPD products also will replicate the behavior of materials more accurately as additional information on material properties becomes available.

The complete integration of VPD tools into a single process, which Algor is working toward through its Mechanical Event Simulation software, will ultimately replace physical prototyping for design verification altogether, enabling companies to develop products faster without compromising safety. In addition, a shorter design cycle for the first three stages of the product life cycle provides progressive, agile companies with the ability to fulfill consumer needs through better quality products and reduced after-market servicing in a more competitive and profitable business environment.