ZeroLengthSection

# ZeroLengthSection

#include <element/zeroLength/ZeroLengthSection.h>

class ZeroLengthSection : public Element

TaggedObject
MovableObject
DomainComponent
Element

The ZeroLengthSection class represents an element defined by two nodes at the same geometric location, hence it has zero length. The nodes are connected by a SectionForceDeformation object which represents the force-deformation relationship for the element.

ZeroLengthSection elements are constructed with a tag in a domain of dimension 2 or 3, connected by nodes Nd1 and Nd2. The vector x defines the local x-axis for the element and the vector yprime lies in the local x-y plane for the element. The local z-axis is the cross product between x and yprime, and the local y-axis is the cross product between the local z-axis and x.

// Constructors

// Destructor

// public methods to obtain information about dof & connectivity

// public methods to set the state of the element

// public methods to obtain stiffness, mass, damping and residual information

// public methods for element output

Construct a ZeroLengthSection element with tag . The force-deformation relationship for the element is obtained by invoking getCopy() on the SectionForceDeformation pointer theSection. The section model acts in the local space defined by the x and yprime vectors. The section axial force-deformation acts along the element local x-axis and the section y-z axes directly corresponsd to the local element y-z axes.

This is the constructor invoked by an FEM_ObjectBroker object. It constructs an empty ZeroLengthSection element with two nodes. The recvSelf() method is invoked on the object for it to set the internal data.

Element destructor deletes memory for storing the section model pointer.

Returns 2.

Return ID of size \(2\) with the node tags defining the element.

Return the number of DOF for the element, which depends on the dimension of the problem and the number of DOF associated with each node.

Initialize element and define data structures. Sets up the element transformation matrix, \(A\), which defines the kinematic relationship between nodal displacements and section deformations.

Commit state of element by committing state of the section. Return 0 if successful, !0 otherwise.

Revert state of element to last commit by reverting to last committed state of the section. Return 0 if successful, !0 otherwise.

Revert state of element to initial state by reverting to initial state of the section. Return 0 if successful, !0 otherwise.

Return tangent stiffness matrix for element. The element tangent is computed from the section tangent matrix, \(k_b\), as \(K_e = A^T k_b A\). The section tangent is obtained by calling getSectionTangent().

Returns the tangent stiffness matrix for the element as the secant stiffness is not defined for SectionForceDeformation objects.

Return a zero damping matrix.

Return a zero mass matrix.

The element has no loads, so this operation has no effect.

The element has no loads, so this operation has no effect and returns 0.

The element has no mass, so this operation has no effect and returns 0.

Return resisting force vector for element. The element resisting force is computed from the section stress resultants, \(s\), as \(P_e = A^T s\). The section stress resulant is obtained by calling getStressResultant().

Returns the result of getResistingForce() as there is no element mass.

Send information about element and the section over a channel.

Receive information about element and section from a channel.

Display element.

Prints the element node tags and section model to the stream em s.

Currently returns -1.

Currently returns -1.