Civil Engineering Reference
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performance by excluding parts of the model that are not likely to interact;
(3) ignoring contact for all the surface pairings specified, even if these inter-
actions are specified directly or indirectly in the contact inclusions defini-
tion; and finally (4) excluding multiple surface pairings from the contact
domain. All of the surfaces specified must be element-based surfaces. Keep
in mind that surfaces can be defined to span multiple unattached bodies, so
self-contact exclusions are not limited to exclusions of single-body contact.
When you specify pure master-slave contact surface weighting for a partic-
ular general contact surface pair, contact exclusions are generated automat-
ically for the master-slave orientation opposite to that specified. ABAQUS
[1.29] assigns default pure master-slave roles for contact involving discon-
nected bodies within the general contact domain, and contact exclusions
are generated by default for the opposite master-slave orientations.
5.2.2.3 Defining Contact Pair Interactions
Contact pairs in ABAQUS [1.29] can be used to define interactions between
bodies in mechanical, coupled temperature-displacement, and heat transfer
simulations. Contact pairs can be formed using a pair of rigid or deformable
surfaces or a single deformable surface. Modelers do not have to use surfaces
with matching meshes. Contact pairs cannot be formed with one 2D surface
and one 3D surface. Modelers can define contact in terms of two surfaces
that may interact with each other as a “contact pair” or in terms of a single
surface that may interact with itself in “self-contact.” ABAQUS enforces
contact conditions by forming equations involving groups of nearby nodes
from the respective surfaces or, in the case of self-contact, from separate
regions of the same surface. To define a contact pair, modelers must indicate
which pairs of surfaces may interact with one another or which surfaces may
interact with themselves. Contact surfaces should extend far enough to
include all regions that may come into contact during an analysis; however,
including additional surface nodes and faces that never experience contact
may result in significant extra computational cost (e.g., extending a slave sur-
face such that it includes many nodes that remain separated from the master
surface throughout an analysis can significantly increase memory usage
unless penalty contact enforcement is used). Every contact pair is assigned
a contact formulation and must refer to an interaction property. Contact for-
mulations are based on whether the tracking approach assumes finite- or
small-sliding and whether the contact discretization is based on a node-
to-surface or surface-to-surface approach. When a contact pair contains
two surfaces, the two surfaces are not allowed to include any of the same
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