Applying Constraints and Forces

Once the flexible body has been created in Adams View, constraints and forces can be applied to it. Just like for other types of bodies in Adams this is done though markers. Adding markers to flexible bodies requires specifying both the location of the marker, as well as the nodes to which it is attached. The position of a marker on a flexible body is treated independently from the nodes to which it is attached. For example, the position of the marker does not need to be coincident with a node.

Joint forces and applied loads are applied at the marker position and then distributed onto the flexible body at the attachment points you specify. How the loads are distributed depends on the marker configuration. For example, the offset behaves like rigid lever on a marker which is not coincident with its attachment node. That is, a force applied to the marker is transferred to the node as a force-moment pair.

Similar to linear flexible bodies modeled for the default Adams Solver executable choice (C++), there are three possible configurations for creating markers on nonlinear flexible bodies. See "Adding Markers to Flexible Bodies" for details and note that the workarounds defined for Adams Solver (FORTRAN) do not apply to nonlinear flexible bodies since they are supported only in Adams Solver (C++).

Also note that the nonlinear flexible body does not support load bearing/applying objects located on solid element nodes. So, only markers which are used, for example, for output requests can placed on such nodes. Markers used for constraint or force definitions cannot be placed at solid element nodes. No such limitation exists for shell-elements. The use of master nodes connected to the load bearing surfaces of the structure through rigid-body elements (RBE) is recommended as the means to connect nonlinear solid-element nonlinear flexible bodies to the rest of the Adams model.