# block contact history command

Syntax

block contact history <name s > location-keyword variable-keyword <keyword ...>

Primary keywords:

Adds a history of a contact value. Review the common c history commands. The history can be assigned a name for later reference with the optional name keyword. If not, the history will be given a default name based on its internally assigned id number.

This command requires that one location-keyword and one variable-keyword are provided. These are shown in groups below.

Histories cannot be assigned for joined contacts. Both blocks involved in the contact must be currently visible.

Keyword Options For location-keyword

contact-id i

Set history location at the contact with ID i. This only applies to contact type histories $$area-sum$$, $$force-normal-sum$$ and $$force-shear-sum$$.

dip f

Only contacts or subcontacts with a dip equal to f will be considered when using the $$position$$ keyword.

dip-direction f

Only contacts or subcontacts with a dip-direction equal to f will be considered when using the $$position$$ keyword.

position v

Set history location at the position v. The history will be recorded for the contact or subcontact nearest to this location.

subcontact-id i

Set history location at the subcontact with ID i.

Keyword Options For variable-keyword

area

Get the area of the subcontact.

area-sum

Get the sum of all subcontact areaa for a given contact.

displacement-normal

Get the normal contact displacement.

displacement-shear

Get the magnitude of shear displacement.

displacement-shear-x

Get the $$x$$-component of shear displacement in global coordinates.

displacement-shear-y

Get the $$y$$-component of shear displacement in global coordinates.

displacement-shear-z

Get the $$z$$-component of shear displacement in global coordinates.

displacement-shear-maximum

Get the maximum shear displacement observed at any time in the past.

force-normal

Get the normal subcontact force.

force-normal-sum

Get the sum of all subcontact normal forces for a given contact.

force-shear

Get the shear contact force.

force-shear-sum

Get the sum of all subcontact shear forces for a given contact.

stress-normal

Get the normal contact stress.

stress-shear

Get the shear contact stress.

stress-shear-x

Get the $$x$$-component of shear stress in global coordinates.

stress-shear-y

Get the $$y$$-component of shear stress in global coordinates.

stress-shear-z

Get the $$z$$-component of shear stress in global coordinates.

velocity-shear

Get the shear contact velocity magnitude.

velocity-shear-x

Get the $$x$$-component of shear velocity in global coordinates.

velocity-shear-y

Get the $$y$$-component of shear velocity in global coordinates.

velocity-shear-z

Get the $$z$$-component of shear velocity in global coordinates.