Civil Engineering Reference
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node-to-surface contact formulation; debonding and cohesive contact behav-
ior; and surface interactions in analyses without displacement degrees of
freedom, such as pure heat transfer and pressure-penetration loading.
Surface-based contact methods associated with general contact and contact
pairs cannot be used for certain classes of problems such as contact interaction
between two pipelines or tubes modeled with pipe, beam, or truss elements
where one pipe lies inside the other; contact between two nodes along a fixed
direction in space; simulations using axisymmetric elements with asymmetric
deformations; and heat transfer analyses where the heat flow is 1D. These
situations require defining a contact simulation using contact elements.
5.2.2.2 Defining General Contact Interactions
ABAQUS [1.29] provides two algorithms for modeling contact and inter-
action problems, which are the general contact algorithm and the contact
pair algorithm. The general contact algorithm is specified as part of the
model definition. It allows very simple definitions of contact with very
few restrictions on the types of surfaces involved. Also, it uses sophisticated
tracking algorithms to ensure that proper contact conditions are enforced
efficiently. It can be used simultaneously with the contact pair algorithm
(i.e., some interactions can be modeled with the general contact algorithm,
while others are modeled with the contact pair algorithm). In addition, it can
be used with 2D or 3D surfaces. Furthermore, it uses the finite-sliding,
surface-to-surface contact formulation.
The definition of a general contact interaction consists of specifying the
general contact algorithm and defining the contact domain (i.e., the surfaces
that interact with one another), the contact surface properties, and the
mechanical contact property models. The general contact algorithm allows
for quite general characteristics in the surfaces that it uses. A convenient
method of specifying the contact domain is using cropped surfaces. Such sur-
faces can be used to perform “contact in a box” by using a contact domain
that is enclosed in a specified rectangular box in the original configuration.
The general contact algorithm uses the surface-to-surface contact formula-
tion as the primary formulation and can use the edge-to-surface contact for-
mulation as a supplementary formulation. The general contact algorithm
does not consider contact involving analytical surfaces or node-based sur-
faces, although these surface types can be included in contact pairs in analyses
that also use general contact. The general contact algorithm can consider 3D
edge-to-surface contact, which is more effective at resolving some interac-
tions than the surface-to-surface contact formulation. The edge-to-surface
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