By Vince Adams
A design engineer shopping for a finite element analysis (FEA) solution these days might be overwhelmed by the available choices. In most cases, one would have to trade off functionality for cost. A common misconception, or rationalization, is that new users only need a linear static solution that analyzes parts. Another misconception is that an FEA solution embedded in one’s CAD system will yield the highest level of productivity due to the integration of features, UI (user interface), and file formats.
Drop test simulation is easy with NEi Fusion’s Automated Impact Analysis.
The reality of FEA in a product design environment is that the solution you need is the one that solves your problems. NEi Fusion from NEi Software (Westminster, CA) has been doing that for designers with powerful, scalable FEA and an interface that rivals the more limited CAD-embedded solutions for ease-of-use. More importantly, in these tough economic times, NEi Fusion is value priced, and, with a Nastran-based core solver, you can have confidence that the results you provide to your customers, be they internal, external, or even yourself, are accurate.
This is the NEi Fusion Feature Tree.
A CAD-Enabled Interface
One of the most striking features of NEi Fusion is that the user interface is powered by SolidWorks. All the geometry creation, modification, and import tools that have made SolidWorks an industry leader are available to NEi Fusion users. Even the Feature Tree motif is maintained in NEi Fusion to provide a natural progression through a project and a convenient way to visualize FE model components. Users are offered a choice between drop-down menus, icon-based toolbars, or Feature Tree interaction.
NEi Fusion benefits from the rich visualization tools that SolidWorks is known for. While users may discount the value of real-time rendering when evaluating FEA tools, this will quickly become one of those features you can’t live without. No one says that powerful simulation can’t be coupled with stunning graphics.
NEi Fusion has integrated solid (volumes), shell (surfaces), and beam (wireframe) elements. This flexibility is important in many engineering environments for growth and scalability. The automated meshing tool is reliable and fast. The beam-element modeling tool is advanced enough to recognize cross-sections of solid geometry while providing a manual property input mode for more experienced users.
NEi Fusion Version 2.0 also includes concentrated mass, spring, bushing, damper, rod, pipe, and cable elements.
NEi Fusion provides a basic set of engineering material data sufficient for determining initial design direction. It also allows you to add or customize any material so that it more directly applies to a specific engineering challenge where more precise results are important.
NEi Fusion also provides composites modeling and failure analysis tools—another high-end capability one wouldn’t expect in a value-priced solution. Furthermore, the ability to perform progressive ply failure analysis (PPFA) is in NEi Fusion V2.0.
Since all NEi Fusion configurations support assemblies, users are encouraged to explore more natural responses as components interact with each other as opposed to guessing at restraints that rarely offer realistic deformations. While experienced analysts may know how to choose and interpret appropriate restraints, part-time and design users should appreciate and take advantage of these assembly-modeling tools.
One of the more unique tools is automatic contact generation. Faces between parts that you indicate as touching, in the assembly mating tools, will be understood as contacting by the Nastran solver. This can save countless hours of modeling time on large assemblies. The effects of friction can be included.
Additionally, NEi Fusion provides a variety of contact types not typically found in value-priced tools, such as welded, sliding, and rough contact. And the expected toolset of standard loads and restraints is still available. These can be coordinate-system based or use geometric references.
In addition to solids and shells, NEi Fusion can model complex beam element structures.
NEi Fusion is packaged two ways. The NEi Fusion Designer product offers Linear Static, Modal, Buckling, Linear Steady-State Heat Transfer, Assembly Modeling with Contact, Optimization, and Composites capabilities. Additionally, the Buckling and Modal, or natural frequency, solvers allow users to include pre-stress effects where tension or compression from operation impacts these responses.
The NEi Fusion Advanced product includes the capabilities of Designer along with Nonlinear Statics, Transient and Frequency Response, Nonlinear Transient Heat Transfer, and Automated Impact Analysis (AIA). This greatly extends a user’s ability to model more realistic structural and thermal conditions, still benefiting from the easy-to-use CAD-enabled UI.
In NEi Fusion V2.0, both the Designer and Advanced products will be coupled with a Nastran Input File editor that opens up an even deeper set of functionality offered by the NEi Nastran product. This is a more traditional analyst interface outside of the NEi Fusion CAD-like environment.
Impact Analysis Wizard
Some of the most difficult types of problems to simulate involve impact between moving parts. A common application is a drop test. Since a meaningful physical drop test isn’t typically possible until production-quality prototypes are available, advance simulation in the design phase can be invaluable. The cost to change a problem found in conceptual design is minimal compared to the cost of changing production tooling.
NEi Fusion has provided AIA to guide engineers through the traditionally complex setup of drop test or impact problems. Simple wizard screens request information on initial velocities or accelerations. NEi Fusion then automatically determines contacting surfaces and solver time-stepping to ensure meaningful results. This feature alone can justify an investment in conceptual analysis.
NEi Fusion hasn’t skimped on results viewing and interpretation tools either. The standard set of stress, strain, displacement, and x,y plot visualization tools are available. Results can be animated and saved to AVI files for project documentation.
A customizable automatic report generation tool is provided with a step-by-step wizard interface. The HTML report created is professional looking and complete.
Another exceptional capability typically offered only in more advanced products is optimization. Once an engineer had determined that performance is acceptable, the optimization tools in NEi Fusion can help to quickly evaluate numerous parameters and geometric configurations. The output from these studies can guide engineers to a minimal cost or weight design while keeping stress or displacement, even natural frequencies, within desired parameters.
When the Solution is Complete…
NEi Fusion has managed to fill the void between complete yet expensive simulation systems and inexpensive yet limited tools. It is a CAD-enabled simulation workhorse with a legacy stretching back to the toughest automotive and aerospace analysts in the market—traditional Nastran users.
Any design engineer or analyst struggling with the limitations of complex interfaces or limited capabilities should give NEi Fusion a hard look. While the product is based on established technologies, NEi Nastran and SolidWorks, the combination is still new enough to show exciting improvement with every release. Couple this with a knowledgeable and willing support team and you have a solution for design analysis with the ability to scale with your growing needs.
Vince Adams is DE’s expert in simulation, having worked and taught in the field for 20 years. He is the co-author of three books and numerous articles on FEA and design analysis. Comments should be sent to DE-Editors@deskeng.com.