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

S-1PAT321, Section , June 2002

SECTION

COMPOSITE MATERIALS


COMPOSITE MATERIALS

Classical Lamination Theory Composite Material Definition QUAD4 and TRIA3 elements Ply Data Recovery Composite Failure Theorems Post Processing Not

Supported in MSC.PATRAN


Ply Definition

Typically a ply is a flat group of fibers imbedded in a matrix.

The matrix is usually an isotropic material that holds the fibers together.

In a ply called a tape, the fibers are unidirectional. In a ply called a cloth, the fibers are woven at 0 and

90 degree directions.


Tape Plies

Fiber: Unidirectional in tape direction is the 1 axis of the ply

coordinate system

Matrix: glue that holds fibers together matrix direction is the 2 axis 90 degrees to the 1 axis

Material properties are: 2D orthotropic material in

Patran MAT8 in Nastran


MAT8 bulk data entry Defines the ply orthotropic properties.

Elastic properties are E1, E2, NU12, G12, G1Z, G2Z. Allowables are Xt, Xc, Yt, Yc, S. Use STRN if allowables are in units of strain. F12 is for the Tsai-Wu failure theorem. Thermal coefficients of expansion are A1 and A2, initial temperature is TREF, density is RHO, damping is GE.

The example below is typical for a graphite/epoxy tape.

1 2 3 4 5 6 7 8 9 10

MAT8 MID E1 E2 NU12 G12 G1Z G2Z RHO

MAT8 1 20.+6 2.+6 0.35 1.5+6 1.6+6 1.4+6 1.3-4

A1 A2 TREF Xt Xc Yt Yc S

-2.3-7 4.5-6 0.0 1.1+5 1.05+5 1.2+4 1.5+4 2.+4

mat8, 1, 20.+6, 2.+6, 0.35, 1.5+6, 1.6+6, 1.4+6, 1.3-4,++, -2.3-7, 4.5-6,, 1.1+5, 1.05+5, 1.2+4, 1.5+4, 2.+4.bdf file extract

GE F12 STRN


Patran 2D Orthotropic

Materials:

Create/ 2d Orthotropic/ Manual Input

Material Name

Input Properties

Linear Elastic

Apply

Input Properties

Failure

Apply


Composite Material Stack of plies Each ply has a different direction,

material, and thickness Composite properties are

calculated in the material coordinate system (Xm, Ym, Zm)

Zm is the same as the element Z axis (Ze)

Xm is either an angle relative to element G1G2 vector or is the projection of the X axis of a defined coordinate system

Positive angles are defined by right hand rule around Zm


PCOMP bulk data entry Defines the composite layup. The example composite below is an 8 ply layup, symmetric about it’s centerline,

with an equal number of plies is each of the 0, +-45, 90 degree directions.

1 2 3 4 5 6 7 8 9 10

PCOMP PID Z0 NSM SB FT TREF GE LAM

PCOMP 1 5000.0 HILL 0.0

MID1 T1 THETA1 SOUT1 MID2 T2 THETA2 SOUT2

1 0.0054 0.0 YES 1 0.0054 45.0 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

MID3 T3 THETA3 SOUT3 ect.

1 0.0054 90.0


Patran Composite

Materials:

Create/ Composite/ Laminate

Click on tape property name for each of the plies

Thickness for all layers: .0054<cr>

Orientations: 0 45 –45 90 90 –45 45 0

Load Text Into Spreadsheet

Apply


CQUAD4 bulk data entry

Defines the composite plate. Material coordinate system

can be defined one of two ways:

MCID – (integer) - ID of a user defined coordinate system who’s X-axis is projected onto the element to define the element’s material coordinate system’s X-axis. This along with the Z-axis of the element coordinate system defines the material coordinate system.

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 element’s Z-axis.

1 2 3 4 5 6 7 8 9 10

CQUAD4 EID PID G1 G2 G3 G4 THETA or MCID

ZOFFS

CQUAD4 1 1 1 2 3 4 99

cquad4,1,1,1,2,3,4,99

cquad4,1,1,1,2,3,4,25.0


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


Patran Material Coord. Z-axis

Elements:

Verify/ Element/ Normals

Draw Normal Vectors

Apply


Patran Material Coord. X-axis

Properties:

Show/ Shell

Orientation Angle

Apply


Patran Ply Output Request

Analysis:

Analyze/ Entire Model/ Full Run

Subcases/ Create

Output Requests/ Advanced/ Element Stress

Ply Stresses

OK

Apply


Patran Ply Stress Results

Attach xdb:

Results:

Create/ Quick Plot

Result/ Stress Tensor

Position/ Layer 1

Quantity/ X Component

Apply


Composite Failure Indices Hill:

SXYX2

2

12221

2

2

22

2

1 t

1, 2, 12 are ply stresses from the Nastran analysis

X, Y, S are ply stress allowables from the PCOMP bulk data entry

F12 is experimentally determined

Hoffman:

YYXXSXXYYXX CTCTCTCTCT

1111

212

2

1221

2

2

2

1 t

Tsai-Wu:

2112212

2

1221

2

2

2

1 *2FYYXXSXXYYXX CTCTCTCTCT

1111t


Composite Failure Indices

Max Strain: Three failure indices One for each direction Uses strain allowables

SFI

YFI

XFI

1212

22

11 ,,

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)

SFI

YFI

XFI 12

122

21

1 ,,

1, 2, 12 are ply stresses from the Nastran analysis

X, Y, S are ply stress allowables from the PCOMP bulk data entry

Max Stress: Same as Max Strain but

allowables are in stress units


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 1 6.6183 0.1776 2 4.1766 0.1822 3 14.5333 0.0315 4 20.0144 20.0144 *** 2 HILL 1 1.8251 0.1288 2 0.9096 0.1322 3 4.0140 0.0228 4 9.5973 9.5973 *** 3 HILL 1 6.0914 0.1912 2 8.4410 0.1961 3 7.4905 0.0339 4 10.2642 10.2642 *** 4 HILL 1 0.0641 0.1153 2 0.8806 0.1183 3 8.7623 0.0204 4 19.9326 19.9326 ***

Nastran Failure Index Output Printed in the f06 file if allowbles on PCOMP bulk data entry are present. Failure index display not supported in Patran.

.f06 file extract

Documents

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