PAT312, Section 51, December 2006 S51-1 Copyright 2007 MSC.Software Corporation SECTION 51 GAP AND CONTACT MODELING

PAT312, Section 51, December 2006 S51-2 Copyright 2007 MSC.Software Corporation

PAT312, Section 51, December 2006 S51-3 Copyright 2007 MSC.Software Corporation GAP BOUNDARY CONDITIONS Gap LBCs are used to facilitate thermal coupling across gaps Gap LBC Data is not written to the Neutral file Radiation Data is written to gap_rad.dat file Convection Data is written to gap_convec.dat Coupled Temperature Data is written to tcoupl.dat

PAT312, Section 51, December 2006 S51-4 Copyright 2007 MSC.Software Corporation BETWEEN REGIONS CONVECTION Create under Convection using options: Fixed Coefficient Input a constant fixed convection coefficient Select a previously created spatial field Time Table Tabular input of time dependent coefficient Temperature Table Tabular input of temperature dependent coefficient Spatial Field (Time) Select a spatial field created using: Fields, Spatial, Tabular Input With dynamic variable Time selected

PAT312, Section 51, December 2006 S51-5 Copyright 2007 MSC.Software Corporation GAP RADIATION Create using Gap Radiation option User input surface emissivities and form factor Spatial variation Select previously created spatial field Time or temperature variation Uncheck Fixed Select previously created Material Property field MPID Created using Fields, Material Property, General Bypasses radiation interchange (viewfactor) calculations Gap radiation conductors calculated:

PAT312, Section 51, December 2006 S51-6 Copyright 2007 MSC.Software Corporation COUPLED TEMPERATURE Create Temperature LBC using Coupled option Enforces same temperature across gap

PAT312, Section 51, December 2006 S51-7 Copyright 2007 MSC.Software Corporation APPLICATION REGIONS There are two application regions Application Region Coupling Region (Region 2) Areas are computed from entities in Application Region Application Region and Coupling Region must both be either Geometry or FEM Cannot mix Application Region and Coupling Region entity types Cannot include the same node or element in both regions Usually an unintentional picking error Analysis breaks down writing gap_convec.dat file

PAT312, Section 51, December 2006 S51-8 Copyright 2007 MSC.Software Corporation APPLICATION REGIONS (Cont.) Order Selection Many-to-one, or one-to-one nodal correspondence Virtually requires identical mesh in both regions Closest Approach (default) Many-to-many nodal correspondence Most useful and robust option Connect between dissimilar meshes Every node in application region has a connector Connected to closest node in coupling region

PAT312, Section 51, December 2006 S51-9 Copyright 2007 MSC.Software Corporation

PAT312, Section 51, December 2006 S51-10 Copyright 2007 MSC.Software Corporation

PAT312, Section 51, December 2006 S51-11 Copyright 2007 MSC.Software Corporation

PAT312, Section 51, December 2006 S51-12 Copyright 2007 MSC.Software Corporation