Learning Forum

[simonfur1]

Dear community,

Ive been hitting the wall lately while performing something so simple as applying contact between to interfacing volume meshes (that simulate a CF-layer and a thin piezo electrical layer).

It will not bond. Running a modal analysis make the parts split in all directions.

I try to avoid using nummrg as I will make the piezo layer much thinner, and apply way more elements to it, making the element amount very different from the top layer to the bottom one. ( Ideal situation for using contact elements)

Please see my attached code. Do anyone have any good ideas?

[peteroznewman]

I have copied your code into this post because ANSYS staff are not permitted to open attachments.

---

/CLEAR

/PREP7

/UIS,MSGPOP,3



/title, Harmonic analysis of a carbon-fibre layered beam with ZnO

!

!

!Element Types                                              !

!

!

!Composite layer element type

ET,1,SOLID185,,,1 !Remember to give same thickness in secdata as in the given volume

!Glass layer element type

ET,2,SOLID185,,,1 !Remember to give same thickness in secdata as in the given volume

!Piezoelectric Element

ET,3,solid226,1001

!Contact element:

ET,4,CONTA174

!Resistor Element

ET,5,CIRCU94,0

!Target element

ET,6,TARGE170



! ELement division:

!attribute for volume (Warning, picked lines cant be one same height)!

*set,plmesh,10 ! mesh for plate=number of segments

*set,pzmesh,20  ! mesh for pzt=number of  segments. Set to the same to avoid additional contact meshing (difference is minimal)

*set,meshthc,1 	!no of element through thickness of piezo

tccf=0.000120 ! cf layer thickness

tcglass=0.00012 ! cf layer thickness

tZnO=1e-4

BeamW = 0.032

BeamL = 0.239

CFL1=0.119

GFL=0.151

CFL2=0.154

! Top electrode size:

Ell=0.1

Elw=0.02

! Offset from clamped edge:

GOff=0.015

CF2off=0.085



!Piezoelectrical lyers offset:

OffsetX1=0

OffsetX2=0.120



!

!

!Material Properties                                        !

!

!

!CF Material Properties

MP,DENS,1,1100		! From measurment of acutal beam

MP,EX,1,45.01e9		!Elastic modulus, x-direction

MP,EY,1,45.01e9	 	!Elastic modulus, y-direction

MP,EZ,1,20e9		!Elastic modulus, z-direction

MP,PRXY,1,0.35		!Major poisson's ratio, x-y plane

MP,PRYZ,1,0.2		!Major poisson's ratio, y-z plane

MP,PRXZ,1,0.35		!Major poisson's ratio, x-z plane

MP,GXY,1,2.892e9		!Shear modulus, x-y plane

MP,GYZ,1,2e9		!Shear modulus, y-z plane

MP,GXZ,1,2e9		!Shear modulus, x-z plane



!Glass Material Properties

MP,DENS,2,1500		! From measurment of acutal beam

MP,EX,2,22.99e9		!Elastic modulus, x-direction

MP,EY,2,22.99e9	 	!Elastic modulus, y-direction

MP,EZ,2,5e9		!Elastic modulus, z-direction

MP,PRXY,2,0.3		!Major poisson's ratio, x-y plane

MP,PRYZ,2,0.2		!Major poisson's ratio, y-z plane

MP,PRXZ,2,0.3		!Major poisson's ratio, x-z plane

MP,GXY,2,2.2627e9	!Shear modulus, x-y plane

MP,GYZ,2,1e9		!Shear modulus, y-z plane

MP,GXZ,2,1e9		!Shear modulus, x-z plane



!! Piezo material properties

MP,DENS,3,1160 				!from resin epoxy. Should be modified when real speciments are prepared

! Anisotropic properties given as resin epoxy, since crystals do hold very little load individually (approximation):

MP,EX,3,3780e6			!3780e6, this is resin epoxy. Use however PZT for comparison

MP,PRXY,3,0.35

MP,GXY,3,1400e6			!From resin epoxy



! See material properties and lirarature overview to see where this is from

MP,PERx,3,877.6

MP,PERy,3,877.6

MP,PERZ,3,1006.3



TB,PIEZ,3,,,0

TBMODIF,1,1
TBMODIF,1,2
TBMODIF,1,3,-0.62 			!e13

TBMODIF,2,1
TBMODIF,2,2
TBMODIF,2,3,				!e23

TBMODIF,3,1
TBMODIF,3,2
TBMODIF,3,3,0.96			!e33

TBMODIF,4,1
TBMODIF,4,2,				!e42

TBMODIF,4,3
TBMODIF,5,1,-0.37			!e51

TBMODIF,5,2
TBMODIF,5,3
TBMODIF,6,1
TBMODIF,6,2
TBMODIF,6,3


!

!

!Geometry Dimensions                                        !

!

!

!Composite layer 1

materid=1 	!material id

ang1=0		!angel of layer in degrees

SECTYPE,1,shell,,layer1 		!define which element type

SECDATA,tccf,materid,ang1 			!define thikncess and angle



!Glass layer

materid=2 	!material id

ang2=0						!angel of layer in degrees

SECTYPE,2,shell,,layer2 			!define which element type

SECDATA,tcglass,materid,ang2 			!define thikncess and angle



!

!

!Reserved Nodes for Circuit                                 !

!

!

!circuit dimension

cirdim = 0.02

n,1,-4*cirdim,0,3*cirdim

n,2,-4*cirdim,0,cirdim

n,3,BeamL+4*cirdim,0,3*cirdim

n,4,BeamL+4*cirdim,0,cirdim

!

!

!FEM Domain Geometries                                      !

!

!

!Create Beam, Epoxy and Piezoelement nr 1 (start on top and go downward)

BLOCK,0,CFL1,-BeamW/2.0,BeamW/2.0,0,tccf ! CF layer 1

BLOCK,0,CFL1,-BeamW/2.0,BeamW/2.0,0,-tZnO !Piezo Layer 1







!

!

!Mesh                                                       !

!

!

! Corner line meshing of all SOLID185 elements (cant be divided in thickness)

LSEL,S,LINE,,9,12,1		!SELECT CORNER LINES OF composite LAYER 1

LESIZE,ALL,,,1			!# OF ELEMENT DIVISION



! Composites layers length/width meshing:

LSEL,S,LINE,,1,3,2			!SELECT SHORT LINES OF beam

LSEL,A,LINE,,6,8,2			!SELECT SHORT LINES OF beam

LESIZE,ALL,,,plmesh			!# OF ELEMENT DIVISION



LSEL,S,LINE,,2,4,2			!SELECT LONG LINES OF beam

LSEL,A,LINE,,5,7,2			!SELECT LONG LINES OF beam

LESIZE,ALL,,,(plmesh*(CFL1/BeamW))	!# OF ELEMENT DIVISION





!Piezoelectrical layer meshing thickness:

LSEL,S,LINE,,21,24,1		!SELECT CORNER LINES OF composite LAYER 1

LESIZE,all,,,meshthc

LSEL,all



!Short side of piezo:

LSEL,S,LINE,,13,15,2			!SELECT SHORT LINES OF beam

LESIZE,all,,,pzmesh



!Long side of piezo:

LSEL,S,LINE,,14,16,2			!SELECT LONG LINES OF beam

LESIZE,ALL,,,(pzmesh*(CFL1/BeamW))	!# OF ELEMENT DIVISION



! Assign material to volumes

VSEL,S,VOLU,,1			!SELECT layer 1

VATT,1,,1			!ASSIGN ELEMENT ATTRIBUTES



VSEL,S,VOLU,,2	    		!SELECT PIEZO PATCH  1

VATT,3,,3			!ASSIGN ELEMENT ATTRIBUTES





VSEL,ALL

!VMESH,1,8,1

vsweep,all



*get,Epz,elem,,count           	! Get all the number of solid elements



!

!

!Bond together layers with the contact and target element   !

!

!

! Define bonded contact, (from Principles of Simulating Contact Between Parts using ANSYS)

KEYOPT,4,2,1

KEYOPT,4,5,1

KEYOPT,4,6,0

KEYOPT,4,7,0

KEYOPT,4,8,2

KEYOPT,4,9,1

KEYOPT,4,11,0

KEYOPT,4,12,5 			! Keyopt 12 set to 5 is a bonded always condition





!Target surface:

ASEL,S,AREA,,1			! Select area at the top and bottom of the patch

TYPE,6				! Selectn element type

real,3				! Sets the element real constant set attribute pointer

NSLA,S,1			! Select those nodes associated with the selected areas

ESLN,S,0			! Select those elements attached to the selected nodes

ESURF,ALL			! Generate elements overlaid on the free faces of selected nodes

ASEL,S,AREA,,8

type,4

real,3

NSLA,S,1

ESLN,S,0

ESURF,ALL





!Check normals:

ESEL,S,TYPE,,4

ESEL,A,TYPE,,6

/PSYMB,ESYS,1

EPLOT



! Reverse Contact Normal (maybe not necessary)

ESEL,NONE

ESEL,A,TYPE,,4

ESURF,,REVERSE

eplot

ESEL,S,TYPE,,4

ESEL,A,TYPE,,6

eplot

/PSYMB,ESYS,0

! CONTACT PAIR CREATION - END



!

!

!

!

!

Open-Circuit Modal Analysis

!

!

!

!

!

/SOLU

antyp,modal

nmodes = 10

MODOPT,LANB,nmodes,0,500

MXPAND,nmodes	!Specifies the number of modes to expand and write for a modal or buckling analysis.

!

!

!Load & Boundary Conditions                                 !

!

!

!Structural BCs

nsel,s,loc,x,0

d,all,ux,0

d,all,uy,0

d,all,uz,0

alls



solve

finish