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 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 link, the resultant deck displacement may be modeled.
- Run a nonlinear large-displacement direct-integration 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 value of less than zero.
- When reviewing model results, do not display the links such that visuals appear as follows:
- Pendulum test problem
- Dropping ball video (zipped AVI file)