S10-1 PAT318, Section 10, March 2005 SECTION 10 ELEMENT PROPERTIES. - презентация

1 S10-1 PAT318, Section 10, March 2005 SECTION 10 ELEMENT PROPERTIES

2 S10-2 PAT318, Section 10, March 2005

3 S10-3 PAT318, Section 10, March 2005 ELEMENT PROPERTY DEFINITION Element Property form is used to specify: Element type and formulation MSC.Nastran lumped point mass, CONM2 ABAQUS solid element standard formulation, C3D8 Cross-section properties 0-D : lumped mass, mass matrix 1-D : A, I yy, I zz, J 2-D : thickness, plate offset, material orientation 3-D : material, integration scheme Region of application Geometry F EM Properties associated with geometry will be re-applied to new mesh after re- meshing

4 S10-4 PAT318, Section 10, March 2005 ELEMENT PROPERTY DEFINITION (Cont) Element properties may vary in space as described by fields, e.g. thickness = 0.10*Y *X**2 Property forms are specific to application code, element type, and configuration

5 S10-5 PAT318, Section 10, March 2005 ELEMENT PROPERTY CREATION First, if necessary select the desired analysis code in Preferences/Analysis Select the dimensionality of the element 0-D (Mass, Spring) 1-D (Beam) 2-D (Shell, 2D Solid) 3-D (Solid) Specify a name (maximum 31 characters) Select element Options Enter properties in the Input Properties form Use Select Members list box and select menu to choose between Geometry or FEM entities Geometric entities FEM entities

6 S10-6 PAT318, Section 10, March 2005 Data templates are finite element solver, element type, and configuration specific Materials may be selected by clicking the Material Prop Name icon, then selecting from the choices in Select Existing Material window PHYSICAL PROPERTY INPUT FORM

7 S10-7 PAT318, Section 10, March 2005 PHYSICAL PROPERTY INPUT FORM (Cont.) Brackets around a data item name denote that the specification of the item is optional, e.g. [Non-structural Mass] indicates Patran will process data without non-structural mass

8 S10-8 PAT318, Section 10, March 2005 BEAM ELEMENT PROPERTIES Bar/Beam elements require a vector to define the orientation of the cross-section (the local element coordinate system) In MSC.Patran, this vector is defined using either the Patran global (X,Y,Z) or a local coordinate system To recover bending stress, stress recovery points must be defined relative to the element coordinate system Called C,D,E,F for MSC.Nastran Used to determine c in the classical equation stress= Mc/I The moments of Inertia (I1 and I2) and the torsional constant (J) are defined with respect to the local element coordinate system (J is not the polar moment of inertia) MSC.Nastran and ABAQUS beam cross-section orientations are explained in the figure on the next page

9 S10-9 PAT318, Section 10, March 2005 BEAM ELEMENT ORIENTATION

10 S10-10 PAT318, Section 10, March 2005 BEAM LIBRARY Optionally, beam sections can be created, viewed and stored in the database A library of standard shapes is available to automatically calculate A, I11, I22, and J Cross-section properties can be calculated for arbitrary shapes Beam Library is available from the Input Properties form of Element Properties, or under Tools, Beam Library Beam sections assigned to elements can be graphically viewed on each element

11 S10-11 PAT318, Section 10, March 2005 DISPLAYING BEAM SECTIONS Beam sections and offsets can be displayed by using Display/Load/BC/Elem. Props…and choosing, for example, 3D:FullSpan+Offsets The actual cross-section and orientation is displayed as shown Only if the beams cross- section is defined with Beam Library If cross-section specified with Area, I 1,1, etc. use …+Equiv. I or A

12 S10-12 PAT318, Section 10, March 2005 PROPERTY SPECIFICATION USING FIELDS Variable Thickness Plate (t = * X * Y3) Create the field Apply the field to the plate as input to the property thickness Show scalar plot of the resulting thickness

13 S10-13 PAT318, Section 10, March 2005 MASS PROPERTIES Mass Properties application is available under Tools for 2D and 3D calculations Can be calculated for selected groups, and can include Geometry, FEM or both n Output includes mass, volume, center of gravity, principal inertias at the center of gravity, the radii of gyration corresponding to the principal inertias at the center of gravity n A user specific coordinate frame may be used n Data can optionally be output to a text report file

14 S10-14 PAT318, Section 10, March 2005