Description: A general contact capability is now provided in Abaqus/Standard with nearly the same user interface as the preexisting general contact capability in Abaqus/Explicit. The general contact algorithm is intended to eventually become the primary contact algorithm, but more robust and economical solutions in Abaqus/Standard can often be obtained with traditional contact pair definitions as compared to highly automated general contact definitions in this initial release of general contact. Some users may prefer to wait for the general contact implementation in Abaqus/Standard to further mature; however, many users will benefit from this initial release of general contact in terms of the simplicity of defining contact and the accuracy of solutions obtained with it.

The contact interaction domain, contact properties, and surface attributes are specified independently for general contact, offering a more flexible way to add detail incrementally to a model. The general contact user interface allows for a highly automated contact definition; however, it is also possible to define contact with the general contact user interface to mimic traditional contact pairs. Most Abaqus/Explicit users have grown accustomed to using general contact in a highly automated form with good success. Reasons why traditional contact pairings will sometimes outperform highly automated general contact definitions in Abaqus/Standard include:

• Extent of contact surfaces: Most Abaqus/Standard users define contact pairs with surfaces that only extend as far as the anticipated contact region and do not wrap around corners. The highly automated form of general contact uses surfaces that wrap around all components in the model, such that contact could occur between any portions of components during the analysis (including self-contact). Overhead costs of including portions of surfaces that never come into contact remain significant in Abaqus/Standard 6.9. Furthermore, having contact surfaces wrap around corners sometimes degrades convergence robustness in Abaqus/Standard.

• Master and slave roles: Most Abaqus/Standard users have learned to assign master and slave roles for contact surfaces such as to maximize robustness. For example, to model a block sliding along a large, smooth surface, making the large, smooth surface act as the master surface will typically result in the most robust solution, because each contact constraint will tend to maintain constant active/inactive status as sliding occurs. General contact in Abaqus/Standard automatically assigns master and slave roles based primarily on the relative mesh refinement.

The general contact capability in Abaqus/Standard uses the finite-sliding, surface-to-surface contact formulation. This formulation and other aspects of general contact in Abaqus/Standard are discussed in the references provided.

Interaction module:
   InteractionCreate: Step: Initial, General contact (Standard)