!!!FEA NL1: POST-BUCKLING ANALYSIS OF A PINNED-PINNED BEAM

!!Initial setup, White canvas and parameters

!
ELAST=200E9
NU = 0.3
L = 3
A = 2/100
B = 5/100
FCR = 7330

!!SETUP: element types, materials, sections

! Define the rectangular crossection
SECTYPESECTYPE, SECID, Type, Subtype, Name, REFINEKEY Associates section type information with a section ID number.,1,BEAM,RECT
SECOFFSETSECOFFSET, Location, OFFSET1, OFFSET2, CG-Y, CG-Z, SH-Y, SH-Z Defines the section offset for cross sections.,CENT
SECDATASECDATA, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6, VAL7, VAL8, VAL9, VAL10, VAL11, VAL12 Describes the geometry of a section.,A,B
! Linear, isotropic, elastic material model
MPTEMPMPTEMP, SLOC, T1, T2, T3, T4, T5, T6 Defines a temperature table for material properties.
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,,ELASTELAST = 200E9
MPDATAMPDATA, Lab, MAT, SLOC, C1, C2, C3, C4, C5, C6 Defines property data to be associated with the temperature table.,PRXY,1,,NU
! Create the keypoints
KK, NPT, X, Y, Z Defines a keypoint.,1,0,0,0
KK, NPT, X, Y, Z Defines a keypoint.,2,L,0,0
! Create the line
LL, P1, P2, NDIV, SPACE, XV1, YV1, ZV1, XV2, YV2, ZV2 Defines a line between two keypoints.,1,2
! Set number of elements
LESIZELESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV Specifies the divisions and spacing ratio on unmeshed lines.,1,,,20
LMESHLMESH, NL1, NL2, NINC Generates nodes and line elements along lines.,1
! Apply geometric constraints at keypoints
DKDK, KPOI, Lab, VALUE, VALUE2, KEXPND, Lab2, Lab3, Lab4, Lab5, Lab6 Defines DOF constraints at keypoints.,1,UX,0
DKDK, KPOI, Lab, VALUE, VALUE2, KEXPND, Lab2, Lab3, Lab4, Lab5, Lab6 Defines DOF constraints at keypoints.,1,UY,0
DKDK, KPOI, Lab, VALUE, VALUE2, KEXPND, Lab2, Lab3, Lab4, Lab5, Lab6 Defines DOF constraints at keypoints.,2,UY,0
! Apply geometric constraints at nodes
DD, Node, Lab, VALUE, VALUE2, NEND, NINC, Lab2, Lab3, Lab4, Lab5, Lab6 Defines degree-of-freedom constraints at nodes.,ALL,UZ,0
DD, Node, Lab, VALUE, VALUE2, NEND, NINC, Lab2, Lab3, Lab4, Lab5, Lab6 Defines degree-of-freedom constraints at nodes.,ALL,ROTX,0
DD, Node, Lab, VALUE, VALUE2, NEND, NINC, Lab2, Lab3, Lab4, Lab5, Lab6 Defines degree-of-freedom constraints at nodes.,ALL,ROTY,0
! Apply load at keypoint
FKFK, KPOI, Lab, VALUE, VALUE2 Defines force loads at keypoints.,2,FX,-1000
FINISHFINISH Exits normally from a processor.
! Calculate prestress effect
/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.
! Carry out the eigen buckling analysis
/SOL/SOLU Enters the solution processor.
ANTYPEANTYPE, Antype, Status, LDSTEP, SUBSTEP, Action Specifies the analysis type and restart status.,1
! Extract te first 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.
! Print mode shapes with undeformed edge
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
FINISHFINISH Exits normally from a processor.

!!Post buckling analysis

! Static analysis
ANTYPEANTYPE, Antype, Status, LDSTEP, SUBSTEP, Action Specifies the analysis type and restart status.,0
! Geometric nonlinearity turned on
NLGEOMNLGEOM, Key Includes large-deflection effects in a static or full transient analysis.,1
! First substep
NSUBSTNSUBST, NSBSTP, NSBMX, NSBMN, Carry Specifies the number of substeps to be taken this load step.,10,10,10
NEQITNEQIT, NEQIT, FORCEkey Specifies the maximum number of equilibrium iterations for nonlinear analyses.,150
TIMETIME, TIME Sets the time for a load step.,5
FINISHFINISH Exits normally from a processor.
/PREP7/PREP7 Enters the model creation preprocessor.
! Delete load at the end keypoint
FKDELEFKDELE, KPOI, Lab Deletes force loads at a keypoint.,2,ALL
! Apply concentrated force on the middle node
FF, NODE, Lab, VALUE, VALUE2, NEND, NINC Specifies force loads at nodes.,12,FY,100
FINISHFINISH Exits normally from a processor.
/SOL/SOLU Enters the solution processor.
LSWRITELSWRITE, LSNUM Writes load and load step option data to a file.,1
! Second substep
TIMETIME, TIME Sets the time for a load step.,10
FINISHFINISH Exits normally from a processor.
/PREP7/PREP7 Enters the model creation preprocessor.
! Apply 99% of the critical force at the end
FKFK, KPOI, Lab, VALUE, VALUE2 Defines force loads at keypoints.,2,FX,-(99/100)*FCR
FINISHFINISH Exits normally from a processor.
/SOL/SOLU Enters the solution processor.
LSWRITELSWRITE, LSNUM Writes load and load step option data to a file.,2
! Third substep
! Between pseudo time 10 and 20 nothing happens
TIMETIME, TIME Sets the time for a load step.,20
LSWRITELSWRITE, LSNUM Writes load and load step option data to a file.,3
! Fourth substep
TIMETIME, TIME Sets the time for a load step.,30
FINISHFINISH Exits normally from a processor.
/PREP7/PREP7 Enters the model creation preprocessor.
! Remove the load at the middle of the beam (set to 0 instead of deleting to have ramped transition)
FF, NODE, Lab, VALUE, VALUE2, NEND, NINC Specifies force loads at nodes.,12,FY,0
FINISHFINISH Exits normally from a processor.
/SOL/SOLU Enters the solution processor.
LSWRITELSWRITE, LSNUM Writes load and load step option data to a file.,4
! Fifth substep
TIMETIME, TIME Sets the time for a load step.,50
FINISHFINISH Exits normally from a processor.
/PREP7/PREP7 Enters the model creation preprocessor.
! Remove the load from the end keypoint (set to 0 instead of deleting to have ramped transition)
FKFK, KPOI, Lab, VALUE, VALUE2 Defines force loads at keypoints.,2,FX,0
FINISHFINISH Exits normally from a processor.
/SOL/SOLU Enters the solution processor.
LSWRITELSWRITE, LSNUM Writes load and load step option data to a file.,5
! Solve problem from subtep 1 to 5
LSSOLVELSSOLVE, LSMIN, LSMAX, LSINC Reads and solves multiple load steps.,1,5,1
! Time history post processing
/POST26/POST26 Enters the time-history results postprocessor.

! This webpage was generated with APDL highlighter (version: 0.1-beta) on: 12.04.2021 15:15:53, from APDL script: script.txt