Linear Spring 01
(If you want to skip this intro, just click here)
The Usfos Linear Spring element is 1 node element (Spring to Ground), which gets it's properties in the 6 degrees of freedom by the stiffness matrix referred to (material). Both full 6x6 matrix with coupling terms and simple diagonal matrix input are available. The properties defined in the stiffness matrix are referred to the global coordinate system, but local (skew) syetems may be defined (3x3 transformation matrix).
The spring has following properties, only one (bold) is mandatroty, the rest are optional:
Spring behaviour and typical use:
Just "linear". (If non linear behaviour is required, try the 1
node non linear spring). The linear spring is typically used as a simple
foundation. To define a pure dashpot damper, just define all 6 degrees of
freedom equal to zero.
Single Beam with Spring Support
A linear spring to ground is attached to both end 1 and 2 of the beam. The spring at end 1 is a "diagonal" spring (defined through the SpriDiag "material"), while the spring in end 2 is defined by a full 6x6 stiffness matrix (SpriFull in ufo format, or MGSPRING in SESAM format). It is possible to combine the spring with "normal" node boundary as demonstrated for Node 1 (has 4 dof's fixed).