3 docs tagged with "springs"

In most analysis no material curve needs to be defined, but for LS-DYNA analysis and for nonlinear springs material curves must be defined.

A spring matrix allows the user to define the stiffness terms explicitly for a nodal spring. The matrix option cannot be used with internal springs.

Springs are a general type of element which can be used to model both simple springs and more sophisticated types of behaviour. For springs connected to ground these are specified directly on a node rather than as an element. The two simplest and most robust types of spring are the axial and rotational springs which have only and axial or rotational stiffness respectively. The more general spring types can violate equilibrium conditions so use be used with care. General non linear springs require material curves to define the load deflection characteristics. A completely general linear spring connected to ground uses a material matrix to define the stiffness, but this matrix must be positive definite. Springs follow the same local axis definition as beam, but the exceptions are zero length springs and nodal springs. For zero length springs the local axis is the constraint axis or the first node and for nodal springs it is the constraint axis of the node.