Shortening the Design Process through FEA (Pt 1)
Finite Element Analysis (FEA) software is used to create computer-generated models of materials or design components.
These are then subjected virtually to mechanical, thermal or other stresses so that engineers can predict material and product performance. The models can be based on profiles or drawings of real-world products. Once all conditions affecting the product, whether it be installation forces, thermal effects, etc., are known, the basis of the model can begin to take shape.
The output of the model can be shown as an animation, synthesizing the real-world application. This analysis is key to eliminating non-functional possibilities and establishing the best material or design without the cost and time of full-scale production testing.
Trelleborg Sealing Solutions has developed innovative ways of creating and using models for FEA to test an ever-expanding range of materials in ever-increasing ways. Trelleborg’s quest for performance has led to improvements in the virtual testing process as well. This results in a more accurate finding and a recommendation in which end users can feel confident investing in.
Means of Visualization
Trelleborg Sealing Solutions has the ability to create simple 2-D models or complex 3-D models. Each has specific applications: 2-D models are typically used for axi-symmetric analysis. Engineers can learn how a product will install, grow from thermal expansion and react to forces applied.
Creating a 3-D model enables a complete visualization of a product. This is important when a product, such as a seal, is not a completely uniform profile or has voids. For example, a gasket can have holes stamped in it for bolts to pass through. A simple 2-D analysis would not capture both the cross-section with the hole through it and the cross-section without the hole. Therefore, a 3-D analysis is needed to visualize increasingly complex profiles.
Elements of a Successful Model
There are several well-established elements involved in creating a successful model for Finite Element Analysis:
- A clear plan of accurate, comprehensive boundary conditions such as hardware interaction with the product or seal. How will the product or seal fit into the surrounding hardware? Does it need to be stretched or contorted for installation? Making sure the product or seal is accurately modeled before other parameters are applied is extremely important.
- A clear and concise understanding of what forces or stresses the product or seal will be subjected to. Will the product or seal be exposed to temperature fluctuations? Will the product or seal be exposed to pressure? What about dynamic movement of the hardware surrounding the product or seal? All conditions the seal will experience must be identified and accounted for in the model.
- A library of accurately modeled materials, (both metallic and non-metallic). Trelleborg Sealing Solutions performs almost all of its analysis on non-metallic materials, which require the need for non-linear modeling. This non-linear modeling is dependent upon the quality of the material properties used in the model. Therefore, all materials must be tested in the real world to determine stress-strain curves, Poissons ratios and all physical material properties. It is critical to test the materials at various temperatures as well since non-metallic materials have non-linear properties. Having accurately tested material properties will greatly increase the quality of the output data.
- A robust FEA program. It is crucial to select a testing partner who offers the latest in modern technology and understands how to use it. Flexibility is also crucial to allow for adaptation or a new direction in analysis.
- A team of analysts representing a range of specialties. No FEA analysis is routine, and a team of experienced people can provide valuable input and ideas to circumvent potential pitfalls. Criteria include a high level of experience in FEA among the team leaders and engineers involved in the design of the product or seal. An FEA analyst may not fully understand the complexity of an application, and product engineers can fill that void. At Trelleborg Sealing Solutions, our FEA analysts work closely with design and product engineers to form the required team of experienced people.