Southborough, MA – December 12, 2013 – With today’s CFEA technology, we can model and evaluate a design in hours or even minutes, thereby minimizing critical lead times and overall production costs. DTI invested in systems and technology that support this design cycle requirement. This past year, DTI leveraged its FEA capabilities to help develop not one, but two new rail sealing solution requirements, for two different OEM’s.
Device Technologies develops open Collaborative Finite Element Analysis (CFEA™) to solve sealing designs utilizing its specialty High Performance Silicone material expertise and design techniques to meet market demand for next generation applications.
The CFEA process is very important and should be considered when there are many variables that may affect sealing performance. During the collaborative review process customer data is collected and a CFEA is completed.
DTi capitalized on the similarities of the two applications. In each application, one for a rail coach window and the other for a locomotive power supply cabinet door, both required Flame, Smoke and Toxicity (FST) material standards and to specifically meet ambient requirements for high heat, harsh outdoor UV exposure and resist corrosion.
In order to satisfy these requirements, DTI’s Seal-Fast™ Silicone Series was evaluated and DTI’s technical team developed an extrusion grade door seal that met the rail industry FST material requirements. Further, when applied to a stainless steel substrate, corrosion resistance and outdoor performance for heat and UV exposure was maximized. (Note: DTI”s Seal-Fast “off- the- shelf” materials are typically with CRS or Aluminum metal core substrates in EPDM and PVC while FDA Approved grade design solutions are also available to meet Pharmaceutical, Food Service and Laboratory needs.)
Once compliance elements were resolved it was time to design the best solution to optimize the specific sealing requirements and also address the installation assembly onto the chassis to conform to the various radii for each application.
Below are two FEA summaries that showcase the Compression Load Deflections (CLD’s) that were necessary to meet all of the above and move from initial inquiry and discussion to FAI production and upon review, test and approval, subsequent volume production. All within a 7-10 week window!
CFEA Summary #1: Locomotive Door Seal
From the collaborative review data collected a numerical technique was used to analyze specific results and verifies that the edge seal will perform to specifications.
In conjunction with the FST and corrosion resistance application requirements, it was important to analyze the seal function. Compression Load Deflections (CLD’s) were analyzed using material data and environment conditions, to verify the design before progressing into the initial FAI production test and approval, and subsequent volume production.
The CFEA process verified that the edge seal maintained elastic properties throughout prolonged compressive stress. Selecting and analyzing the correct material and profile design for the application improved the resistance to permanent deformation when exposed to compressive stress for an extended period of time (in a constant or changing pressure/release state). The solution increased longevity from the previous seal used, maintaining a tight seal under low and high compressive forces created from opening and closing exterior access doors in changing environmental conditions.
CFEA Summary #2: Coach Car Body/ Window Seal
This window seal was critically challenging as the glass was also convex in shape and the corner radii were designed prior to the seal solution and that dictated certain design attributes for material wall thickness, as well as wing seal thickness and length that were a departure from our standard off the shelf seal profiles. While not an intentional design attribute at the beginning, the wing seal style was selected over a typical bulb seal approach and in so doing this gave the customer further application flexibility to make the design more universal across other rail coach window designs with very modest in- situ metal bracket changes.
Device Technologies offers a variety of standard silicone profiles that meet these and other industry requirements such as FMVSS, FDA (Pharma and food service) and a variety of ASTM standards. Technical application engineers are available to discuss your requirements and determine if we can model up an FEA to meet your requirements.
DTi continues to invest in R & D to enhance opportunities for its product and process technologies, in compliance with ISO 9001 and AS 9100 standards. More information is available by calling (508)-229-2000.