Reviewing the Adjustments of Initially Overclosed Surfaces
Contacting surfaces that are overclosed in the initial configuration of the model are adjusted automatically by Abaqus/Explicit to remove the overclosures (see Contact Initialization for General Contact in Abaqus/Explicit and Contact Initialization for Contact Pairs in Abaqus/Explicit). There are three sources of information on the adjustments of overclosed surfaces: the status (.sta) file, the message (.msg) file, and the output database (.odb) file.
Obtaining the Adjustments of Overclosed Surfaces in the Status and Message Files
By default, Abaqus/Explicit writes all nodal adjustments and—for general contact surfaces—contact offsets to the message (.msg) file along with a summary listing of the maximum initial overclosure and the maximum nodal adjustment to the status (.sta) file for the contact pairs defined in the first step of a simulation. You can choose to suppress the information written to the message file and write only the summary information to the status file. The information written to the message and status files is also written to the output database (.odb) for use in Abaqus/CAE.
Input File Usage
Use the following option to obtain both detailed diagnostic output to the message file and summary diagnostic output to the status file:
DIAGNOSTICS, CONTACT INITIAL OVERCLOSURE=DETAIL (default)
Use the following option to obtain only summary diagnostic output to the status file (no contact diagnostics will be written to the message file):
DIAGNOSTICS, CONTACT INITIAL OVERCLOSURE=SUMMARY
Abaqus/CAE Usage
You cannot control the diagnostic information for contact initial overclosures from within Abaqus/CAE. Use the following option to view the saved diagnostic information:
Visualization module: Viewing the Adjustments of Surfaces
In the first step the adjustments of initially overclosed surfaces can be viewed in Abaqus/CAE. Displaced shape plots that show the adjustments to the contact pairs defined in the first step can be plotted for the original field output frame at zero time (this nodal coordinate adjustment may introduce small nonzero strain output for solid elements even when the stresses are zero). In addition, output variable STRAINFREE (see Abaqus/Explicit Output Variable Identifiers) contains nodal vectors representing initial strain-free adjustments. By default, STRAINFREE is written to the output database (.odb) file for the original field output frame at zero time if any strain-free adjustments are made by Abaqus/Explicit. A symbol plot of this variable in the Visualization module of Abaqus/CAE shows vectors that represent how individual nodes have been adjusted, and a contour plot of this variable shows the distribution of the adjustment magnitude (you must select the original output frame at zero time in the Visualization module of Abaqus/CAE before choosing the STRAINFREE output variable). In the case of overclosures in steps other than the first, vector plots of nodal displacements and accelerations can be particularly helpful in visualizing the adjustments. Such plots can be viewed in Abaqus/CAE after a data check analysis (see Abaqus/Standard and Abaqus/Explicit Execution).
Visualizing the Precise Initial Clearances for Small-Sliding Contact Pairs
Abaqus/Explicit does not adjust the coordinates of the secondary surface when precise initial clearances are specified for small-sliding contact pairs (see Contact Initialization for Contact Pairs in Abaqus/Explicit). Therefore, the specified clearances cannot be seen in a postprocessor such as the Visualization module of Abaqus/CAE. Thus, depending on the initial geometry of the surfaces and the magnitude of the clearances or overclosures, the surfaces may appear open or closed in the postprocessor when they are actually just in contact in the simulation.