FEA ST4: STABILITY ANALYSIS OF A CYLINDRICAL SHELL

! Created by Tamas Poloskei, 2017. February 28.

Units: [N],[Nmm],[N/mm^2=MPa],[N/mm]

Define constant parameters

D = 100
H = 150
T = 1
ELAST = 210E3
NU = 0.3

SETUP: element types, materials, sections

KEYWKEYW, Keyword, KEY Sets a keyword used by the GUI for context filtering (GUI).,PR_STRUC,1! Preferences / Structural
/PREP7/PREP7 Enters the model creation preprocessor.
ETET, ITYPE, Ename, KOP1, KOP2, KOP3, KOP4, KOP5, KOP6, INOPR Defines a local element type from the element library.,1,SHELL181
MPTEMPMPTEMP, SLOC, T1, T2, T3, T4, T5, T6 Defines a temperature table for material properties.,1,0
MPDATAMPDATA, Lab, MAT, SLOC, C1, C2, C3, C4, C5, C6 Defines property data to be associated with the temperature table.,EX,1,,ELAST
MPDATAMPDATA, Lab, MAT, SLOC, C1, C2, C3, C4, C5, C6 Defines property data to be associated with the temperature table.,PRXY,1,,NU
/RGB/RGB, Kywrd, PRED, PGRN, PBLU, N1, N2, NINC, NCNTR Specifies the RGB color values for indices and contours.,INDEX,100,100,100,0
/RGB/RGB, Kywrd, PRED, PGRN, PBLU, N1, N2, NINC, NCNTR Specifies the RGB color values for indices and contours.,INDEX,0,0,0,15

! thickness definition
SECTSECTYPE, SECID, Type, Subtype, Name, REFINEKEY Associates section type information with a section ID number.,1,SHELL
SECDATASECDATA, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, VAL7, VAL8, VAL9, VAL10, VAL11, VAL12 Describes the geometry of a section.,T,1,0.0,3
SECOFFSETSECOFFSET, Location, OFFSET1, OFFSET2, CG-Y, CG-Z, SH-Y, SH-Z Defines the section offset for cross sections.,MID
SECCONTROLSECCONTROL, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, VAL7, VAL8, VAL9, VAL10, VAL11, VAL12, VAL13 Supplements or overrides default section properties.
! Create keypoints
KK, NPT, X, Y, Z Defines a keypoint.,1,0,0,0
KK, NPT, X, Y, Z Defines a keypoint.,2,0,0,H
! Create circle
CIRCLECIRCLE, PCENT, RAD, PAXIS, PZERO, ARC, NSEG Generates circular arc lines.,1,D/2,,,360,4
! Create line to be swept along
LL, P1, P2, NDIV, SPACE, XV1, YV1, ZV1, XV2, YV2, ZV2 Defines a line between two keypoints.,1,2
! Extrude the lines of the circle
ADRAGADRAG, NL1, NL2, NL3, NL4, NL5, NL6, NLP1, NLP2, NLP3, NLP4, NLP5, NLP6 Generates areas by dragging a line pattern along a path.,1,2,3,4,,,5
! Set the number of elements on each line
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,1,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,2,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,3,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,4,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,6,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,9,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,11,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,13,,,10
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,7,,,20
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,8,,,20
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,10,,,20
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,12,,,20
! Mesh areas as mapped
MSHKEYMSHKEY, KEY Specifies whether free meshing or mapped meshing should be used to mesh a model.,1
AMESHAMESH, NA1, NA2, NINC Generates nodes and area elements within areas.,ALL
! Activate cylindrical coordinate system
CSYSCSYS, KCN Activates a previously defined coordinate system.,1
! Before element orientation
/PSYMB/PSYMB, Label, KEY Shows various symbols on displays.,ESYS,1
GPLOTGPLOT Controls general plotting.
! Rotate every elements local coordinatesystem
NROTATNROTAT, NODE1, NODE2, NINC Rotates nodal coordinate systems into the active system.,ALL
GPLOTGPLOT Controls general plotting.
! Kinematic constraints
! Bottom edge
*DO*DO, Par, IVAL, FVAL, INC Defines the beginning of a do-loop.,III,1,4
  DLDL, LINE, AREA, Lab, Value1, Value2 Defines DOF constraints on lines.,III,,UX,0
  DLDL, LINE, AREA, Lab, Value1, Value2 Defines DOF constraints on lines.,III,,UY,0
  DLDL, LINE, AREA, Lab, Value1, Value2 Defines DOF constraints on lines.,III,,UZ,0
*ENDDO*ENDDO Ends a do-loop and starts the looping action.
! Uncomment the next lines to apply the b) exercise's constraints
! DL,6, ,UX,0
! DL,6, ,UY,0
! DL,6, ,UY,0
! *DO, III, 9, 13, 2
! DL,III, ,UX,0
! DL,III, ,UY,0
! DL,III, ,UY,0
! *ENDDO
!
! Apply loads
SFASFA, Area, LKEY, Lab, VALUE, VALUE2 Specifies surface loads on the selected areas.,ALL,1,PRES,-1
FINISHFINISH Exits normally from a processor.
! Activate prestress effects
/SOL/SOLU Enters the solution processor.
PSTRESPSTRES, Key Specifies whether prestress effects are calculated or included.,1
/STATUS/STATUS, Lab Lists the status of items for the run.,SOLU
SOLVESOLVE, Action Starts a solution.
FINISHFINISH Exits normally from a processor.
! eigen buckling
/SOL/SOLU Enters the solution processor.
ANTYPEANTYPE, Antype, Status, LDSTEP, SUBSTEP, Action Specifies the analysis type and restart status.,1
! Extract four modes
BUCOPTBUCOPT, Method, NMODE, SHIFT, LDMULTE, RangeKey Specifies buckling analysis options.,LANB,4,0,0,CENTER
MXPANDMXPAND, NMODE, FREQB, FREQE, Elcalc, SIGNIF, MSUPkey, ModeSelMethod Specifies the number of modes to expand and write for a modal or buckling analysis.,4,0,0,0,0.001,
/STATUS/STATUS, Lab Lists the status of items for the run.,SOLU
SOLVESOLVE, Action Starts a solution.
/POST1/POST1 Enters the database results postprocessor.
! Save eigenshapes into files
SETSET, Lstep, Sbstep, Fact, KIMG, TIME, ANGLE, NSET, ORDER Defines the data set to be read from the results file.,FIRST
PLNSOLPLNSOL, Item, Comp, KUND, Fact, FileID Displays results as continuous contours.,U,SUM,2,1.0
/IMAGE/IMAGE, Label, Fname, Ext, -- Allows graphics data to be captured and saved.,SAVE,eigenshape_1,bmp
SETSET, Lstep, Sbstep, Fact, KIMG, TIME, ANGLE, NSET, ORDER Defines the data set to be read from the results file.,NEXT
PLNSOLPLNSOL, Item, Comp, KUND, Fact, FileID Displays results as continuous contours.,U,SUM,2,1.0
/IMAGE/IMAGE, Label, Fname, Ext, -- Allows graphics data to be captured and saved.,SAVE,eigenshape_2,bmp
SETSET, Lstep, Sbstep, Fact, KIMG, TIME, ANGLE, NSET, ORDER Defines the data set to be read from the results file.,NEXT
PLNSOLPLNSOL, Item, Comp, KUND, Fact, FileID Displays results as continuous contours.,U,SUM,2,1.0
/IMAGE/IMAGE, Label, Fname, Ext, -- Allows graphics data to be captured and saved.,SAVE,eigenshape_3,bmp
SETSET, Lstep, Sbstep, Fact, KIMG, TIME, ANGLE, NSET, ORDER Defines the data set to be read from the results file.,NEXT
PLNSOLPLNSOL, Item, Comp, KUND, Fact, FileID Displays results as continuous contours.,U,SUM,2,1.0
/IMAGE/IMAGE, Label, Fname, Ext, -- Allows graphics data to be captured and saved.,SAVE,eigenshape_4,bmp