Modeling a contact with a plane can be handled in SAP2000 using gap elements and time history analysis with large displacements. Please refer to the below description for developing a model of a sphere A contact surface may be modeled using gap (compression-only) link objects and large-displacement time-history analysis. To demonstrate, the sequence of a sphere dropping onto a flexible deck .
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is modeled as follows:
- Use traditional modeling techniques to create a sphere and a deck.
- Use a gap (compression-only) link to connect the sphere and the deck. The gap joints on each object, which will create the contact point upon impact, must align exactly. By using a gap object, the resultant deck displacement may be modeled.
- Run a nonlinear large-displacement direct-integration analysis that suddenly ramps up gravity load. Large-displacements is required. Include some stiffness- and mass-proportional damping. time-history analysis which amplifies gravity load, causing the sphere to impact the deck. Mass- and stiffness-proportional damping should be included, along with small time steps and a Hilber-Hughes-Taylor alpha < 0. Use fairly small time-steps.When displaying the value of less than zero.
- When reviewing model results, do not show display the links .
Screenshots
- such that visuals appear as follows:
See Also
- Pendulum test problem
Attachments
- Dropping ball video (Zipped zipped AVI file, 3 MB)