Explicit
3-D Spar (or Truss)
LINK160 Element Description
LINK160 has three degrees of freedom at each node and carries an axial force.
This element is used in explicit dynamic analyses only. Refer to the LS-DYNA Theoretical Manual for more information.
LINK160 Input Data
The geometry and node locations are shown in Figure 160.1: LINK160 Geometry. Node K determines the initial orientation of the cross section. For this element, you can choose three materials: isotropic elastic, plastic kinematic, and bilinear kinematic.
The element is defined by nodes I and J in the global coordinate system. Node K defines a plane (with I and J) containing the element s-axis. The element r-axis runs parallel to the length of the element and through nodes I and J. Node K is always required to define the element axis system and it must not be colinear with nodes I and J. The location of node K is used only to initially orient the element.
Use the EDLOAD command to apply nodal loads (displacements, forces, etc.). Also use EDLOAD to apply loads on rigid bodies. For more information on how to apply loads in an explicit dynamic analysis, see Loading in the ANSYS LS-DYNA User's Guide.
A summary of the element input is given in "LINK160 Input Summary". A general description of element input is given in Element Input.
LINK160 Input Summary
- Nodes
I, J, K (K is the orientation node)
- Degrees of Freedom
UX, UY, UZ, VX, VY, VZ, AX, AY, AZ
For explicit dynamics analyses, V (X, Y, Z) refers to nodal velocity, and A (X, Y, Z) refers to nodal acceleration. Although V (X, Y, Z) and A (X, Y, Z) appear as degrees of freedom, they are not actually physical degrees of freedom; however, these quantities are computed as degree-of-freedom solutions and stored for postprocessing.
- Real Constants
Area - Cross-sectional area
- Material Properties
TB command: See Element Support for Material Models for this element. MP command: EX, NUXY, DENS, ALPD, BETD, DMPR EDMP command: RIGID - Surface Loads
None
- Body Loads
None
- Special Features
All nonlinear features allowed for an explicit dynamic analysis.
- KEYOPTS
None
LINK160 Output Data
Output data for LINK160 consists of the following: Axial force
To output the data, you must use the ETABLE command. For the ITEM label, specify SMISC. For the COMP label, specify 1 for axial force. Then, you can use the PRETAB command to print the output data.
LINK160 Assumptions and Restrictions
The spar element assumes a straight bar, axially loaded at its ends with uniform properties from end to end.
The length of the spar must be greater than zero, so nodes I and J must not be coincident.
The cross-sectional area must be greater than zero.
The displacement shape function implies a uniform stress in the spar.