Membrane definition

@MEMBRANE_DEFINITION {
@MEMBRANE_NAME {MbnName} {
@FACE_NAME {FaceName}
@MEMBRANE_PROPERTY_NAME {MbnPropName}
@GRAPHICAL_PARAMETERS_NAME {GrfParamName}
@COMMENTS {CommentText}
}
}

Introduction

A membrane is a flexible body that is associated with a face, FaceName, used for the representation of multibody systems.

The geometry of the membrane is inherited from the face, FaceName, which must have an associated surface, SurfaceName. The bounding curves of the surface, must match the curves associated with the edges of the face. The finite element discretization of the membrane is controlled by the curve mesh parameters that must be associated with each curve. The curve mesh parameter defined for opposite curves of the face must match.

NOTES

  1. The structural mass and stiffness properties of the membrane are specified by the membrane properties, MbnPropName.
  2. It is possible to attach comments to the definition of the object; these comments have no effect on its definition.

Graphical parameters

The appearance of the membrane during the visualization phase of the analysis can be controlled by associating graphical parameters, GrfParamName to the element.

The following representations are valid for membrane: RprType = MESH or SURFACE. The MESH representation depicts the surface of the membrane as mesh of individual elements, whereas the SURFACE representation shows its surface as an area. Default value: MESH.

Sensors

  1. Sensors can be defined to extract information about modal super-elements. The following SensorType and associated FrameName specifications are allowed for modal super-elements: ACCELERATIONS, DISPLACEMENTS, FORCES, POSITIONS, STRAINS, VELOCITIES. (Default value: DISPLACEMENTS).
  2. The location of the sensor within the membrane element is determined by a u value (0 ≤ u ≤ 1) and a v value (0 ≤ v ≤ 1) that correspond to the η and ζ values over the surface defining the membrane element.