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S-1PAT321, Section, June 2002 SECTION COMPOSITE MATERIALS.

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Presentation on theme: "S-1PAT321, Section, June 2002 SECTION COMPOSITE MATERIALS."— Presentation transcript:

1 S-1PAT321, Section, June 2002 SECTION COMPOSITE MATERIALS

2 S-2PAT321, Section, June 2002 COMPOSITE MATERIALS n Classical Lamination Theory n Composite Material Definition n QUAD4 and TRIA3 elements n Ply Data Recovery n Composite Failure Theorems Post Processing Not Supported in MSC.PATRAN

3 S-3PAT321, Section, June 2002 Ply Definition n Typically a ply is a flat group of fibers imbedded in a matrix. n The matrix is usually an isotropic material that holds the fibers together. n In a ply called a tape, the fibers are unidirectional. n In a ply called a cloth, the fibers are woven at 0 and 90 degree directions.

4 S-4PAT321, Section, June 2002 Tape Plies n Fiber: u Unidirectional in tape u direction is the 1 axis of the ply coordinate system n Matrix: u glue that holds fibers together u matrix direction is the 2 axis u 90 degrees to the 1 axis n Material properties are: u 2D orthotropic material in Patran u MAT8 in Nastran

5 S-5PAT321, Section, June 2002 MAT8 bulk data entry n Defines the ply orthotropic properties. u Elastic properties are E1, E2, NU12, G12, G1Z, G2Z. u Allowables are Xt, Xc, Yt, Yc, S. u Use STRN if allowables are in units of strain. u F12 is for the Tsai-Wu failure theorem. u Thermal coefficients of expansion are A1 and A2, u initial temperature is TREF, u density is RHO, u damping is GE. n The example below is typical for a graphite/epoxy tape MAT8MIDE1E2NU12G12G1ZG2ZRHO MAT A1A2TREFXtXcYtYcS mat8, 1, 20.+6, 2.+6, 0.35, 1.5+6, 1.6+6, 1.4+6, 1.3-4,+ +, , 4.5-6,, 1.1+5, , 1.2+4, 1.5+4, 2.+4.bdf file extract GEF12STRN

6 S-6PAT321, Section, June 2002 Patran 2D Orthotropic Materials: Create/ 2d Orthotropic/ Manual Input Material Name Input Properties Linear Elastic Apply Input Properties Failure Apply

7 S-7PAT321, Section, June 2002 Composite Material n Stack of plies n Each ply has a different direction, material, and thickness n Composite properties are calculated in the material coordinate system (Xm, Ym, Zm) n Zm is the same as the element Z axis (Ze) n Xm is either an angle relative to element G1G2 vector or is the projection of the X axis of a defined coordinate system n Positive angles are defined by right hand rule around Zm

8 S-8PAT321, Section, June 2002 PCOMP bulk data entry n Defines the composite layup. n The example composite below is an 8 ply layup, symmetric about its centerline, with an equal number of plies is each of the 0, +-45, 90 degree directions PCOMPPIDZ0NSMSBFTTREFGELAM PCOMP HILL0.0 MID1T1THETA1SOUT1MID2T2THETA2SOUT YES YES pcomp,1,,,5000.0,hill,,,,+ +,1,.0054, 0.0,yes,1,.0054, 45.,yes,+ +,1,.0054,-45.,yes,1,.0054, 90.,yes,+ +,1,.0054, 90.,yes,1,.0054,-45.,yes,+ +,1,.0054, 45.,yes,1,.0054, 0.0,yes.bdf file extract MID3T3THETA3SOUT3ect

9 S-9PAT321, Section, June 2002 Patran Composite Materials: Create/ Composite/ Laminate Click on tape property name for each of the plies Thickness for all layers:.0054 Orientations: 0 45 – – Load Text Into Spreadsheet Apply

10 S-10PAT321, Section, June 2002 CQUAD4 bulk data entry n Defines the composite plate. n Material coordinate system can be defined one of two ways: u MCID – (integer) - ID of a user defined coordinate system whos X-axis is projected onto the element to define the elements material coordinate systems X- axis. This along with the Z-axis of the element coordinate system defines the material coordinate system. u THETA – (real) - an angle between the G1G2 vector of the element and the X-axis of the material coordinate system. The positive sense of this angle is the right hand rule direction around the elements Z-axis CQUAD4EIDPIDG1G2G3G4THETA or MCID ZOFFS CQUAD cquad4,1,1,1,2,3,4,99 cquad4,1,1,1,2,3,4,25.0

11 S-11PAT321, Section, June 2002 Patran Composite Properties Properties: Create/ 2D/ Shell Option: Laminate Input Properties Click on composite material name Click on coord. sys. for projection to material coord. sys. OK Select elements Apply

12 S-12PAT321, Section, June 2002 Patran Material Coord. Z-axis Elements: Verify/ Element/ Normals Draw Normal Vectors Apply

13 S-13PAT321, Section, June 2002 Patran Material Coord. X-axis Properties: Show/ Shell Orientation Angle Apply

14 S-14PAT321, Section, June 2002 Patran Ply Output Request Analysis: Analyze/ Entire Model/ Full Run Subcases/ Create Output Requests/ Advanced/ Element Stress Ply Stresses OK Apply

15 S-15PAT321, Section, June 2002 Patran Ply Stress Results Attach xdb: Results: Create/ Quick Plot Result/ Stress Tensor Position/ Layer 1 Quantity/ X Component Apply

16 S-16PAT321, Section, June 2002 Composite Failure Indices n Hill: 1, 2, 12 are ply stresses from the Nastran analysis X, Y, S are ply stress allowables from the PCOMP bulk data entry F 12 is experimentally determined n Hoffman: n Tsai-Wu:

17 S-17PAT321, Section, June 2002 Composite Failure Indices n Max Strain: u Three failure indices u One for each direction u Uses strain allowables 1, 2, 12 are ply strains from the Nastran analysis X, Y, S are ply strain allowables from the PCOMP bulk data entry (set STRN term on PCOMP to 1.0) 1, 2, 12 are ply stresses from the Nastran analysis X, Y, S are ply stress allowables from the PCOMP bulk data entry n Max Stress: u Same as Max Strain but allowables are in stress units

18 S-18PAT321, Section, June 2002 F A I L U R E I N D I C E S F O R L A Y E R E D C O M P O S I T E E L E M E N T S ( Q U A D 4 ) ELEMENT FAILURE PLY FP=FAILURE INDEX FOR PLY FB=FAILURE INDEX FOR BONDING FAILURE INDEX FOR ELEMENT FLAG ID THEORY ID (DIRECT STRESSES/STRAINS) (INTER-LAMINAR STRESSES) MAX OF FP,FB FOR ALL PLIES 1 HILL *** 2 HILL *** 3 HILL *** 4 HILL *** Nastran Failure Index Output n Printed in the f06 file if allowbles on PCOMP bulk data entry are present. n Failure index display not supported in Patran..f06 file extract


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