WS14-3 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Model Description The purpose of this exercise is to create a model with less guidance that has been provided in previous exercises. When the model is ready for analysis you will open a UNIX shell or Windows Explorer window and observe the sequence of file creation paying special attention to files which provide feedback on the progress of the analysis. The model must meet the following requirements (see figure on p 14-6). 2-1x1x0.001 meter plates with an MID of 353 (steel). Plate surface normals shall face each other. Each plate shall have a quadrant overlapping the other such that each plate has a corner point coincident with the center point of the other plate in plane view. The plates shall have a 0.05m gap between them. Each plate shall have a mesh of 12x12 quad elements (global edge length 0.083). Only one vertical edge of each plate shall have fixed boundary temperatures. The left most edge of one plate (x=0) shall be 0 degrees Celsius; the right most edge of the other plate (x=1.5) shall be 150 degrees Celsius. The two plates shall be thermally coupled by a single radiation boundary condition. Each plate has an Emissivity of 0.1. Use a TID of 100 and an Enclosure ID of 1. Turn OFF the collapse flag when building your VFAC template. All boundary conditions and element properties shall be applied to geometry.
WS14-4 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Objectives Build a simple two plate model which meets specified requirements. Prepare the model for analysis and observe the file creation and analysis process. Run the analysis and use utility commands and Explorer windows to monitor the progress of the analysis. Exercise Overview 1. Open a new database named exercise_14.db. 2. Create a model which meets the specified requirements. 3. Review your model against the checklist of questions. 4. Open a UNIX shell before submitting the model for analysis. 5. Submit the model for analysis and use the commands described to monitor its progress. 6. Debug, if necessary and resubmit after deleting all the files in the job named subdirectory. 7. Read in results file and plot results. 8. Quit MSC.Patran.
WS14-5 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 1: Open a New Database Create a new database called exercise_14.db. a. File / New. b. Enter exercise_14 as the file name. c. OK. d. Choose Default Tolerance. e. Select MSC.Thermal as the Analysis Code. f. Select Thermal as the Analysis Type. g. OK. a b c d e f g
WS14-6 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 2: Create a Model Create a model which meets the specified requirements. a. Based on what you have practiced, create the model according the model description. b. When completed, the model should look like the following figures. c. Note: The radiation boundary condition Input Data form has several list boxes for data entry. Despite the fact that all of the list boxes on the Input Data form appear to be required entries, it is only needed to provide an Enclosure ID and a VFAC Template ID for this exercise. The other fields will be explored further in Exercise x 12 quad 4 mesh Global Edge Length Template.dat.apnd VFAC – 1 x 1 x meter plates Mild Steel MID=353 (0, 0, 0.05) (0.5, 0.5, 0) Exercise 14
WS14-7 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 3: Review the Model Review your model against the checklist of questions. a. Did you use the various view icons to verify the placement of geometry? b. Did you check surface normals using Geometry: Show/Surface/Normal? c. Is the element type 2D/Shell with Material 353 and thickness of 0.001?. d. Was your Target Element Type: 2D for the radiation boundary condition? e. Did you plot LBC markers to verify 2 fixed temperatures and radiation? f. Does the radiation LBC use VFAC Template ID=100 and Enclosure ID=1? g. Have you created template.dat.apnd with the following information? * Basic radiation template without collapse flag VFAC and no blank lines? h. In the Analysis form have you set: Requested Calculation and Output Temperature scales to degrees Celsius? i. Have you requested Perform Viewfactor in Solution Type form?
WS14-8 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 4: For Those Using UNIX, Open a UNIX Shell Open a UNIX shell before submitting the model for analysis. a. Once the model is verified, the template.dat.apnd file is created, and all data for the Analysis form is entered, iconify the MSC.Patran viewport and open a new UNIX shell to get a UNIX prompt. b. Use the UNIX ls and cd commands to get to the directory in which the database resides. c. When in the directory, type at the following at the prompt $ cd exercise_14but do not press or enter In Windows, simply monitor the creation of the files and view the file sizes with a directory window set to show file details
WS14-9 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 5: Submit the Model for Analysis and Monitor Progress Submit the model for analysis and use the commands described to monitor its progress. a. Return to the open Analysis form and click on Apply. b. After the Command Line History Window stops scrolling and the Heartbeat is again green, change focus to the UNIX window and use the cd exercise_14 command with a carriage return. Repeated execution of ls within the Job Name subdirectory will show you the progress of your analysis: Once the file vf.msg.01 appears, type: $ tail -f vf.msg.01 c. This will provide a continuous status of the viewfactor run. d. When the viewfactor analysis is complete it will end with the status message Successful Execution Completed. e. Use the c key combination to terminate the tail function. f. Repeatedly execute a sequence of ls commands until a stat.bin file appears in the directory list. Once the stat.bin file has been created, type: $ qstat c to monitor the progress of the network analysis. This command will self terminate after 20 repetitions or upon job completion. Monitor the data using the qstat command to determine the numerical status of the analysis. g. Check for the existence of an nr0.nrf.01 results file. If it exists the numerical analysis is complete.
WS14-10 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 6: Debug for a Failed Run Debug, if necessary, and resubmit after deleting all the files in the job named directory. a. If Step 4 does not yield a results file then determine what went wrong. b. Is there a patqb.log file? c. If so, then is there a patq.msg file? If there is no patqb.log file then look in the MSC.Patran Command Line History Window or in the MSC.Patran interface for any error messages. d. If there is a patqb.log file and no patq.msg file then look for error messages in patqb.log. e. If there is a patq.msg file then look for error messages in it. f. If there are no error messages in the patq.msg file but this analysis requests that a viewfactor run be made then is there a vf.msg file? g. If there is a vf.msg file then look for error messages in it. h. For this analysis answering the above questions should provide a clue to the problem. Once the error is found and resolved repeat Steps 4 and 5. Remember that now many of the files will have an extension index which has been incremented by 1,e.g., vf.msg.01 to vf.msg.02. If it is convenient you may delete all the files from the exercise_14 Job named subdirectory prior to resubmitting the analysis.
WS14-11 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Read and Plot Results Read results file and plot results. a. Analysis. b. Read Result/Result Entities. c. Click on Select Results File… d. Under directories find the path that leads to exercise_14. e. Select nr0.nrf.01 for available files. f. OK. g. Click Select Rslt Template File… h. Select pthermal_1_nodal. res_tmpl. i. OK. j. Apply. a b c d f g h i j e
WS14-12 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 7: Read and Plot Results Plot the results. a. Results. b. Create/Quick Plot. c. Select Time: D+00S… for Select Result Cases. d. Select Temperature for Select Fringe Result. e. Select the Fringe Attributes icon. f. Select Element Edges for Display. g. Click Label Style… h. Select Fixed for Label Format. i. Use the slide bar to select 4 Significant figures. j. OK. k. Apply. a b f g h i j k
WS14-13 PAT312, Workshop 14, December 2006 Copyright 2007 MSC.Software Corporation Step 8: Quit MSC.Patran. Quit MSC.Patran. a. Select File. b. Click Quit from the drop down menu.