PAT312, Section 18, December 2006 S18-1 Copyright 2007 MSC.Software Corporation SECTION 18 LOADS & BOUNDARY CONDITIONS. - презентация

1 PAT312, Section 18, December 2006 S18-1 Copyright 2007 MSC.Software Corporation SECTION 18 LOADS & BOUNDARY CONDITIONS

2 PAT312, Section 18, December 2006 S18-2 Copyright 2007 MSC.Software Corporation

3 PAT312, Section 18, December 2006 S18-3 Copyright 2007 MSC.Software Corporation LOAD AND BOUNDARY CONDITIONS l Loads and boundary conditions are analysis code specific l They can be applied to geometry or finite elements l Properties associated to geometry will be re-applied to new mesh after re-meshing, editing, etc. l Fields are used to define variations in loads or boundary conditions l Can use imported results from previous analysis - FEM field

4 PAT312, Section 18, December 2006 S18-4 Copyright 2007 MSC.Software Corporation CREATING LOAD/BOUNDARY CONDITIONS l Select the appropriate Load/BC from the Object option box (i.e. Pressure, Temperature, Inflow,...) l Select the Load Case applicable to this load/boundary condition l We recommend not using more than 31 characters for set names l Enter Target Element Type if required (1-D, 2-D, or 3-D) l Input the appropriate data on the Input Data form l Select the Application Region (Geometry or Finite Elements(FEM))

5 PAT312, Section 18, December 2006 S18-5 Copyright 2007 MSC.Software Corporation THERMAL LOAD & BOUNDARY CONDITIONS l Load & boundary conditions form is analysis code and analysis type sensitive. l Shown are the load & boundary conditions sets supported by MSC.Thermal. Action: Object: Type:

6 PAT312, Section 18, December 2006 S18-6 Copyright 2007 MSC.Software Corporation CONVECTION HEAT TRANSFER EXAMPLE l Shown: l Uniform temperature of 300K on left edge l A spatially varying (function of Y) convection coefficient along the right edge using a field l Convecting to a fixed ambient temperature of 300K l A heat flux of 3000 W/m 2 on the surface l Default is adiabatic where no LBC is defined

7 PAT312, Section 18, December 2006 S18-7 Copyright 2007 MSC.Software Corporation THERMAL LOAD & BOUNDARY CONDITIONS l Varying edge Convection Coefficient is specified in a Field l The Application Region is determined by using the select menu (element, element edge, or free edges)

8 PAT312, Section 18, December 2006 S18-8 Copyright 2007 MSC.Software Corporation SHOWING LOADS/BCS l Created load and boundary conditions can be verified using: l Marker Plots showing created Load/BCs icons l Displacement l Rotation l Displacement and Rotation l Temperature l Force l Display tables showing the Loads/BCs in a spreadsheet format l Contour plots of any scalar data quantity (Fringe and Element fill)

9 PAT312, Section 18, December 2006 S18-9 Copyright 2007 MSC.Software Corporation PLOTTING LOADS/BCS l Fringe plots of any Load/BC can be plotted such as: l Temperatures l Components of a vector l The desired vector must be selected from the select data variable box l The vectors must now be used to create a scalar for plotting l The plot can be applied to all of the groups in the current viewport l To display Loads/BCs set applied to geometry on the FEM, first, activate Show on FEM Only toggle in Display/Load/BC/El. Props form, then Plot Markers in the Loads/BCs form

10 PAT312, Section 18, December 2006 S18-10 Copyright 2007 MSC.Software Corporation PLOTTING LOAD/BCS - EXAMPLE l Fringe plot of varying force is rendered in the elements in the FA_gp group while the other elements in Default_group are plotted with null data

11 PAT312, Section 18, December 2006 S18-11 Copyright 2007 MSC.Software Corporation DISPLAY OF LOAD/BCS l Applied Loads/BCs become part of the graphics display. Screen refreshes and view changes will not remove them l Control of all or individual Loads/BCs display is done through the Display/Load/BC/El. Props form l Allows color coding of Loads/BCs Markers l Evaluate load & boundary condition sets applied to geometry on finite elements by selecting Show on FEM Only l Labeling and scaling of vectors are adjusted in the Vectors/Filters section

12 PAT312, Section 18, December 2006 S18-12 Copyright 2007 MSC.Software Corporation LOAD/BCS INPUT DATA SYNTAX l The correct syntax is shown above the databoxes

13 PAT312, Section 18, December 2006 S18-13 Copyright 2007 MSC.Software Corporation LOAD/BC INPUT DATA METHODS l Loads may be applied to FEM or Geometry entities l The Select Geometry Entities box and the Add button are used to select various application regions on the model l Clicking on Add will add the contents of the Select box to the Application Region l Also, select an entity and click remove to remove it from the selection l The contents of the Application Region can be edited using standard databox editing features l Clicking on OK will accept the entities in the Application Region box and close the form

14 PAT312, Section 18, December 2006 S18-14 Copyright 2007 MSC.Software Corporation

15 PAT312, Section 18, December 2006 S18-15 Copyright 2007 MSC.Software Corporation LOAD CASES

16 PAT312, Section 18, December 2006 S18-16 Copyright 2007 MSC.Software Corporation

17 PAT312, Section 18, December 2006 S18-17 Copyright 2007 MSC.Software Corporation LOAD CASE CREATION l Group multiple Load/Boundary Conditions l Each load case has a unique name l Static or Time Dependent l May be created, shown, modified, or deleted l Priorities to add or overwrite Load/Boundary Condition sets can be specified l All LBC sets are automatically included in the default load case

18 PAT312, Section 18, December 2006 S18-18 Copyright 2007 MSC.Software Corporation LOAD CASE CREATION (Cont.) l Load Case Create not currently used for MSC.Thermal preference l Load Cases may be created prior to the creation of Load/Boundary Conditions for other preferences l Specify a load case name (31 characters recommended) l Select Load Case Type l To specify time dependent Load/Boundary Conditions, one must first create a Time Dependent load case l Rules for resolving multiple applications of Load/Boundary Conditions on nodes or elements may be specified under Prioritize

19 PAT312, Section 18, December 2006 S18-19 Copyright 2007 MSC.Software Corporation ASSIGN/PRIORITIZE LOAD/BCS l There are three ways to effect the Scale Factor of LBC sets l One is to edit the LBC Scale Factor Input Box l The second is to have the LBC Scaling Mode set to Add. Everytime you click on an LBC to add to the Spreadsheet, it will add on factor of the value in the Selection Multiplier. l Finally, the Load Case Scale Factor multiplies all of the Load/BC Scale Factors by 25 in this case. So the effective Scale of Displacement Y-symmetry is 25*(-2) = - 50

20 PAT312, Section 18, December 2006 S18-20 Copyright 2007 MSC.Software Corporation