The most commonly used node-to-node element is shown in the following figure.
In terms of solution CPU time, the CONTA178 element shown is the simplest and least expensive of all contact element types. When modeling conditions warrant its use, it can be an effective tool for modeling a variety of contact situations. Following are some notable features offered with CONTA178:
Several contact algorithms, including the Lagrange method (KEYOPT(2))
Semiautomatic contact stiffness (real constants FKN-FKS)
Flexibility for defining contact normal
Many contact behaviors (KEYOPT(10))
Cylindrical, radial, and spherical gaps with friction (KEYOPT(1))
Damper (real constants CV1, CV2)
Multiphysics contact (KEYOPT(6),TCC, ECC)
Real constants in tabular format
User subroutines for user-defined friction, interface interactions, and real constants (USERFRIC, USERINTER, and USERCNPROP)