Anybody have experience with NASTRAN's glue element approach of connecting surfaces with dissimilar meshes? They seem to be working out well in static stress models, but for dynamic models, I am having a lot of trouble getting 6 rigid body modes. I am working with shell elements, and some of my frequencies that should be zero are on the order of 0.1. Sanity checks show that even if the surfaces are right on top of each other and nodes are coincident, this still happens. All I've been able to do to produce thee sought near-zero rigid body frequencies is drop the penalty factor to a point at which the glue effect is not accurately captured in the non-rigid body modes. Any advice?
Literature states that the internally generated glue elements are essentially very stiff springs, but does not explain further.
Red Flag Submitted
Thank you for helping keep Eng-Tips Forums free from inappropriate posts. The Eng-Tips staff will check this out and take appropriate action.
Reply To This Thread
Posting in the Eng-Tips forums is a member-only feature.
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each personâ€™s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now
This whitepaper describes the role of thermal transient measurement to characterize semiconductor thermal behavior. It focuses on the value measurement derived structure functions provide through interpretation of the heat flow path inside a package for use in thermal characterization, failure diagnosis, and improving simulation thermal model accuracy. Download Now
By leveraging comprehensive digital twins of both product and production, manufacturers can design and validate assembly processes and entire facilities virtually, improving quality and accelerating the ramp-up to volume production. Download Now
Itâ€™s easy to fall in love with your own CAD design on the computer screen, but itâ€™s how everything fits together off the screen that really matters. Beyond the design, products need to solve real-life problems or provide huge benefits that genuinely merit separating money from wallets. Download Now