Within SAP2000, CSiBridge, and ETABS, a link object may be used to manually input a known 12x12 stiffness matrix which represents the connection between two joints.
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A one-joint link provides a 6x6 stiffness between a single joint j and the ground. This is the same is the same as using a two-joint link and fully restraining joint i. The stiffness for the one-joint link is thus given by [Kj j ]. This means that the same link property can be used for a one-joint link or a two-joint link that has its first joint fully restrained. The same consideration for the sign of the 5th row and 5th column applies due to V2 = -F2.
See Also
CSI Analysis Reference Manual (The Link/Support Element - Basic) – further information on the general use of links
- Derivation of link equations article