ZeroLengthImpact3D: Difference between revisions

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This command constructs a node-to-node zero-length contact element in 3D space.  
This command constructs a node-to-node zero-length contact element in 3D space to simulate the impact/pounding and friction phenomena.  


{|  
{|  
| style="background:yellow; color:black; width:800px" | '''element zeroLengthImpact3D $tag $slaveNode $masterNode $direction $initGap $frictionRatio $Kt $Kn $Kn2 $Delta_y $cohesion'''
| style="background:yellow; color:black; width:800px" | '''element zeroLengthImpact3D $tag $cNode $rNode $direction $initGap $frictionRatio $Kt $Kn $Kn2 $Delta_y $cohesion'''
|}
|}


----
----


{|
{|
|  style="width:150px" | '''$eleTag''' || unique element object tag
|  style="width:150px" | '''$tag''' || Unique element object tag
|-
| '''$cNode''' || Constrained node tag
|-
| '''$rNode''' || Retained node tag
|-
|-
| '''$sNode''' || Slave Node tag
| '''$direction''' ||  
 
1 if out-normal vector of master plane points to +X direction
 
2 if out-normal vector of master plane points to +Y direction
 
3 if out-normal vector of master plane points to +Z direction
 
|-
|-
| '''$mNode''' || Master node tag
| '''$initGap''' || Initial gap between retained plane and constrained plane
|-
|-
| '''$Nodes ...''' || Slave and master node tags respectively
| '''$frictionRatio''' || Friction ratio in two tangential directions (parallel to retained and constrained planes)
|-
|-
| '''$Kn''' || Penalty in normal direction
| '''$Kt''' || Penalty in two tangential directions
|-
|-
| '''$Kt''' || Penalty in tangential direction
| '''$Kn''' || Penalty in normal direction (normal to retained and constrained planes)
|-
|-
| '''$mu''' || friction coefficient
| '''$Kn2''' || Penalty in normal direction after yielding based on Hertz impact model
|-
|-
| '''$c''' || cohesion (not available in 2D)
| '''$Delta_y''' || Yield deformation based on Hertz impact model
|-
|-
| '''$dir''' || Direction flag of the contact plane (3D), it can be:
| '''$cohesion''' || Cohesion, if no cohesion, it is zero
|}
 
----


1 Out normal of the master plane pointing to +X direction
NOTES:
# This element has been developed on top of the “zeroLengthContact3D”. All the notes available in [[ ZeroLengthContact_Element | “zeroLengthContact3D” wiki page ]] would apply to this element as well. It includes the definition of retained and constrained nodes, the number of degrees of freedom in the domain, etc.
# Regarding the number of degrees of freedom (DOF), the end nodes of this element should be defined in 3DOF domain. For getting information on how to use 3DOF and 6DOF domain together, please refer to OpenSees documentation and forums or see the zip file provided in the EXAMPLES section below.
# This element adds the capabilities of [[ Impact_Material | “ImpactMaterial” ]] to [[ ZeroLengthContact_Element | “zeroLengthContact3D.” ]]
# For simulating a surface-to-surface contact, the element can be defined for connecting the nodes on constrained surface to the nodes on retained surface.
# The element was found to be fast-converging and eliminating the need for extra elements and nodes in the modeling process.


2 Out normal of the master plane pointing to +Y direction
----


3 Out normal of the master plane pointing to +Z direction
EXAMPLES:
|}


[[Image:ZeroLengthContact.png]]
#The following zip file contains an example script and the corresponding input cyclic displacement: [[File:Example script 2.zip]]
#The following zip file contains an example script on how to use 6DOF domain and 3DOF domain together: [[File:Example script 6DOF 3DOF.zip]]


NOTES:
<!--
----


# The contact element is node-to-node contact. Contact occurs between two contact nodes when they come close. The relation follows Mohr-coulomb law: T = $mu * N + $c, where T is tangential force and N is normal force across the interface. $mu is friction coefficient and $c is total cohesion (summed over the effective area of contact nodes)
SAMPLE COMMAND (example scripts are available at bottom of this page):
# The contact node pair in node-to-node contact element is termed "master node" and "slave node", respectively. Master/slave plane is the contact plane which the master/slave node belongs to. The discrimination is made solely for contact detection purpose. User need to specify the corresponding out normal of the master plane, and this direction is assumed to be unchanged during analysis. For simplicity, 3D contact only allows 3 options to specify the directions of the contact plane. The convention is: out normal of master plane always points to positive axial direction (+X or +Y, or +Z)
# For 2D contact, slave nodes and master nodes must be 2 DOF. For 3D contact, slave nodes and master nodes must be 3 DOF.
# The resulted tangent from the contact element is '''NON-SYMMETRIC'''. Switch to non-symmetric matrix solver.


<source lang="Tcl">


</source>
-->
----
----


EXAMPLES:
REFERENCES:  


Gang Wang to provide a smart example!
[[ ZeroLengthContact_Element | zeroLengthContact3D ]] , [[ Impact_Material | ImpactMaterial ]]


----
----


CODE DEVELOPED BY:
:<span style="color:blue"> Dr. Arash E. Zaghi and Majid Cashany at University of Connecticut (UConn) </span>


REFERENCES:
----


APPLICATIONS:
# This element has been employed to simulate the bridge hinges including superstructure-abutment interaction at the University of Connecticut (UConn) and University of Nevada, Reno (UNR).
# It has been implemented in non-structural systems like suspended ceilings, simulating the impact/pounding and friction phenomena.




----
<!--
After running the example script, the following hysteresis loop is resulted in normal direction under cyclic excitation:


Code Developed by: <span style="color:blue"> Arash E. Zaghi, Majid Cashany, University of Connecticut (UConn) </span>
[[File: HysteresisLoop.png]]
-->

Latest revision as of 16:19, 13 June 2020




This command constructs a node-to-node zero-length contact element in 3D space to simulate the impact/pounding and friction phenomena.

element zeroLengthImpact3D $tag $cNode $rNode $direction $initGap $frictionRatio $Kt $Kn $Kn2 $Delta_y $cohesion

$tag Unique element object tag
$cNode Constrained node tag
$rNode Retained node tag
$direction

1 if out-normal vector of master plane points to +X direction

2 if out-normal vector of master plane points to +Y direction

3 if out-normal vector of master plane points to +Z direction

$initGap Initial gap between retained plane and constrained plane
$frictionRatio Friction ratio in two tangential directions (parallel to retained and constrained planes)
$Kt Penalty in two tangential directions
$Kn Penalty in normal direction (normal to retained and constrained planes)
$Kn2 Penalty in normal direction after yielding based on Hertz impact model
$Delta_y Yield deformation based on Hertz impact model
$cohesion Cohesion, if no cohesion, it is zero

NOTES:

  1. This element has been developed on top of the “zeroLengthContact3D”. All the notes available in “zeroLengthContact3D” wiki page would apply to this element as well. It includes the definition of retained and constrained nodes, the number of degrees of freedom in the domain, etc.
  2. Regarding the number of degrees of freedom (DOF), the end nodes of this element should be defined in 3DOF domain. For getting information on how to use 3DOF and 6DOF domain together, please refer to OpenSees documentation and forums or see the zip file provided in the EXAMPLES section below.
  3. This element adds the capabilities of “ImpactMaterial” to “zeroLengthContact3D.”
  4. For simulating a surface-to-surface contact, the element can be defined for connecting the nodes on constrained surface to the nodes on retained surface.
  5. The element was found to be fast-converging and eliminating the need for extra elements and nodes in the modeling process.

EXAMPLES:

  1. The following zip file contains an example script and the corresponding input cyclic displacement: File:Example script 2.zip
  2. The following zip file contains an example script on how to use 6DOF domain and 3DOF domain together: File:Example script 6DOF 3DOF.zip

REFERENCES:

zeroLengthContact3D , ImpactMaterial


CODE DEVELOPED BY:

Dr. Arash E. Zaghi and Majid Cashany at University of Connecticut (UConn)

APPLICATIONS:

  1. This element has been employed to simulate the bridge hinges including superstructure-abutment interaction at the University of Connecticut (UConn) and University of Nevada, Reno (UNR).
  2. It has been implemented in non-structural systems like suspended ceilings, simulating the impact/pounding and friction phenomena.