PATRAN参数化建模教程

1MSC.Patran 2003 Features and Capabilities PARAMETRIC PARAMETRIC MODELINGMODELING 2MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING ‹ Provide automated parametric analysis in support of complex design processes ‹ Allow users to parametrically investigate and assess a number of different designs via batch submittal of a number of different design studies ‹ Permits the use of named variables to replace the usual fixed numerical values of the modeling parameters ‹ The values of these parameters different than the prescribed default can be provided by an external file ‹ Configuration file ‹ Generate output file containing pertain analysis data ‹ Assign result value to a variable for additional calculation & processing ‹ The goal is to make it possible for the user to use names and default values for variables (parameters) in every entry point on every form that can be accessed for modeling purposes 3MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING ‹ A new toolbox implemented as an adaptive form accessed from the main menu bar and called “Parametric Modeling” has been developed ‹ Variables definition mode z Define a variable name and its default value to be used during the modeling process ‹ Response variables creation mode z Search through and manipulate the results of analysis to define meaningful metrics for export to an external file 4MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING „ Variable creation 5MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING „ Macro creation 6MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING „ Responsive variable creation 7MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING „ Steps in parametric modeling 1. Create variables/macros 2. Assign variables to specific Patran actions 3. Define desired results as output variables 4. Create and assign a configuration file 5. Run the session file containing variable settings and Patran actions 6. Iterate analysis process using data stored in the output file 8MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING „ Configuration file format „ The configuration file is used to reset existing Parametric Modeling variables to new values „ The format of the configuration file is: name = value ! comment „ Here are some examples. maximum = 1000 ! this is an integer three = 1, 2, 3 ! this is a 3 word integer array data = 37.655 ! this is a real moredata = 1.0, 2.0, 3.0, 4.0 ! this is a 4 word real array name = mat1 ! this is a string variable, note no quotes names = one, two, three ! this is a string array, again no quotes „ Configuration filenames are case sensitive 9MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING SCENARIOS ‹ Using variables and configurations ‹ Marco definitions and usage ‹ Output definitions 10MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Model a cylinder with a hole through it „ Vary the cylinder radius and height 11MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Part dimensions cyl_radius cyl_height 6 * cyl_radius cyl_height / 23 * cyl_radius hole_radius 12MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 1: Define variables 13MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 1: Define variables ‹ cyl_height = 60 ‹ cyl_radius = 10 ‹ hole_radius = 2 14MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 2: Create a cylinder using the variables 15MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Create the cutter and subtract it from the cylinder 16MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 3: Set up the configuration files ‹ Quit Patran ‹ Create relevant configuration file(s) ‹ These files contains the new variable definitions. my_config_1.dat my_config_2.dat my_config_3.dat cyl_height = 55 cyl_radius = 15 hole_radius = 2 cyl_height = 45 cyl_radius = 25 hole_radius = 2 cyl_height = 50 cyl_radius = 20 hole_radius = 2 17MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 4: Run the session file created earlier ‹ Assign the configuration file using an environment variable: parametric_modeling_config_file ‹ Or assign the configuration file using the following command: ‹ In the command line ‹ In the session file parametric_modeling_util.define_user_config_file (“my_config_1.dat”) ‹ When the session file is played, Patran looks for the variable definitions contained in the configuration file ‹ By creating/editing the configuration file and re-playing the session file, the parametric modeling process is automated ‹ The parametric process can be executed in batch ‹ Patran –spf -b 18MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 4: Run the session file created earlier Vary the cylinder height Vary the cylinder height & radius 19MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING SCENARIOS ‹ Using variables and configurations ‹ Marco definitions and usage ‹ Output definitions 20MSC.Patran 2003 Features and Capabilities CASE STUDY: DESIGN EXPLORATION CANTILEVER BEAM „ Structural analysis of a cantilever beam „ Distributed loads of 1500 lbs „ Fixed end „ Vary the beam cross section „Height „Width 21MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 1: Define variables „ Width = 2 „ Height = 4 „ Length = 50 „ Element_size_length = 2 „ element size along the beam „ Element_size_section = 1 „ element size @ cross section 22MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 2: Define macros „ Pressure_loading „ 1500 / area „ Area = length * width „ Mesh_seed_length „ Length / Element_size_length „ Convert the result into an integer value „ Mesh_seed_width „ Width / Element_size_section „ Convert the result into an integer value „ Mesh_seed_height „ Height / Element_size_section „ Convert the result into an integer value 23MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 3: Create the initial geometry „ Create the 4 x 2 x 50 solid „ Use variables „ `length` „ `width` „ `height` 24MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 4: Define mesh seeds & generate mesh „ Use macros to define mesh seeds „ `mesh_seed_length()` „ `mesh_seed_width()` „ `mesh_seed_height()` „ Generate hex8 elements 25MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 5: Define loads and boundary conditions „ Use macro to define the pressure loading „ `pressure_loading` 26MSC.Patran 2003 Features and Capabilities CASE STUDY: CANTILEVER BEAM „ Step 6: Set up the configuration file ‹ Quit Patran ‹ Create relevant configuration file: ‹ Height = 3 ‹ Width = 3 ‹ Length = 50 ‹ Run the session file ‹ Model has been revised ‹ Pressure loading is updated accordingly ‹ Top surface area was 100 ‹ Top surface area is now 150 my_config.dat height = 3 width = 3 length = 50 27MSC.Patran 2003 Features and Capabilities PARAMETRIC MODELING SCENARIOS ‹ Using variables and configurations ‹ Marco definitions and usage ‹ Output definitions 28MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION CANTILEVER BEAM „ Constant distributed loads of 1500 lbs „ Initial cross section of 3 x 3 „ Examine 2 analysis criteria „Maximum displacement at free end „Maximum bendinf stress at fixed end „ Vary the beam cross section to 4 x 2 „ Reexamine the analysis criteria 29MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 1: Define output variable „ Maximum displacement at free end „ Use variables „ Output type = Nodal Vector „ Quantity = Y Component „ Target = Nodes at the free end 30MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 2: Define output variable „ Maximum bending stress at fixed end „ Use variables „ Output type = Element Tensor „ Location = At Node „ Quantity = Y Component „ Target = Elements at the fixed end 31MSC.Patran 2003 Features and Capabilities CASE STUDY: PARAMETRIC MODELING „ Step 3: Run the session file created earlier ‹ In addition to the configuration file environment variables or PCL commands ‹ The following environment variables or PCL commands are needed to generate the external output file Parametric_modeling_util.print_all_output() ‹ Enable the printing of output variables if the output file is already defined ‹ Assign the output file using an environment variable: parametric_modeling_output_file ‹ Or assign the configuration file using the following command: ‹ In the command line ‹ In the session file parametric_modeling_util.define_user_output_file (“my_output.dat”) 32MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 4: Perform initial analysis my_config.dat height = 3 width = 3 length = 50 33MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 5: Examine output file ! ! VARIABLES ! Real length = 50 ! Real width = 3 ! Real height = 3 ! Real element_size_length = 2 ! Real element_size_section = 1 ! ! ! MACROS ! area() = 150. ! Top surface area pressure_loading() = 10 mesh_seed_length() = 25. mesh_seed_width() = 3. mesh_seed_height() = 3. ! ! OUTPUTS ! Real max_displacement = -1.084347E-3 ---> At Node 2 ! maximum displacement at free end Real Max_stress = 8.131680E+3 ---> At Element 51 ! Maximum bending stress Output variables & results 34MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 6: Iterate analysis process „ New configuration file my_config_1.dat height = 4 width = 2 length = 50 35MSC.Patran 2003 Features and Capabilities CASE STUDY: ANALYSIS ITERATION „ Step 7: Examine output file ! ! VARIABLES ! Real length = 50 ! Real width = 2 ! Real height = 4 ! Real element_size_length = 2 ! Real element_size_section = 1 ! ! ! MACROS ! area() = 100. ! Top surface area pressure_loading() = 15 mesh_seed_length() = 25. mesh_seed_width() = 2. mesh_seed_height() = 4. ! ! OUTPUTS ! Real max_displacement = -8.418538E-4---> At Node 2 ! maximum displacement at free end Real Max_stress = 6.930413E+3---> At Element 76 ! Maximum bending stress Output variables w/ new results Automatic update of macro values 36MSC.Patran 2003 Features and Capabilities