Tensile Test This LS-DYNA example shows a tensile test on a flat specimen using isogeometric analysis (IGA) with trimmed NURBS shells including elasto-plastic material and element deletion. It also shows one way to apply boundary conditions on isogeometric shells. The results are obtained with LS-DYNA R14. https://www.dynaexamples.com/iga/tensile-test https://www.dynaexamples.com/@@site-logo/LS-DYNA-Examples-Logo480x80.png

Tensile Test

This LS-DYNA example shows a tensile test on a flat specimen using isogeometric analysis (IGA) with trimmed NURBS shells including elasto-plastic material and element deletion. It also shows one way to apply boundary conditions on isogeometric shells. The results are obtained with LS-DYNA R14.

Keywords
Reduced Input
Reduced Input IGA Model
Figures
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*BOUNDARY_PRESCRIBED_MOTION_SET
*BOUNDARY_SPC_SET
*CONTROL_SHELL 
*CONTROL_TERMINATION
*CONTROL_TIMESTEP
*DATABASE_BINARY_D3PLOT 
*DATABASE_BNDOUT
*DATABASE_CROSS_SECTION_PLANE
*DATABASE_EXTENT_BINARY
*DATABASE_HISTORY_NODE
*DATABASE_NODOUT
*DATABASE_SECFORC 
*DEFINE_BOX
*DEFINE_CURVE_TITLE
*END
*IGA_1D_BREP
*IGA_1D_NURBS_UVW
*IGA_2D_NURBS_XYZ
*IGA_EDGE_UVW
*IGA_EDGE_XYZ
*IGA_FACE_XYZ
*IGA_POINT_UVW
*IGA_SHELL
*INCLUDE
*KEYWORD
*MAT_PIECEWISE_LINEAR_PLASTICITY
*NODE
*PARAMETER_EXPRESSION
*PART
*SECTION_IGA_SHELL
*SET_IGA_POINT_UVW
*SET_NODE_GENERAL_TITLE
*TITLE

$===============================================================================

$ IGA Shell Tensile Test

$===============================================================================

$ === Units: mm, ms, kg, kN, GPa ====

$===============================================================================

*KEYWORD

$===============================================================================

*TITLE

IGA Shell Tensile Test

$===============================================================================

$ Parameters

$===============================================================================

*PARAMETER_EXPRESSION

$ Simulation end time

R te 90

$ d3plot output time interval

R dtplot &te/50.

$ binary output time interval

R dtbin &te/1000.

$===============================================================================

$ CONTROL cards

$===============================================================================

*CONTROL_TERMINATION

$# endtim endcyc dtmin endeng endmas nosol

&te

*CONTROL_TIMESTEP

$# dtinit tssfac isdo tslimt dt2ms lctm erode ms1st

0.0 0.9 0 0.0 0.0 0 0 0

$# dt2msf dt2mslc imscl unused unused rmscl emscl ihdo

0.0 0 0 0.0 0.0 0

$# - igado dtusr dtdynv

1 0.0 0

*CONTROL_SHELL

$# wrpang esort irnxx istupd theory bwc miter proj

30.0 4

$===============================================================================

$ PART cards

$===============================================================================

*PART

$# title

Probe

$# pid secid mid eosid hgid grav adpopt tmid

1 1 100 0 0 0 0 0

$===============================================================================

$ IGA SECTION and SHELL cards

$===============================================================================

*SECTION_IGA_SHELL

$# secid elform shrf nip irl qr/irid icomp

1 3 0.833 5 0 0.0 0

$# t unused unused unused nloc

1.0 0.0

*IGA_SHELL

$# sid pid nisr niss idfne

1 1 0.0 0.0 0 0 0 0

$===============================================================================

$ MATERIAL cards

$===============================================================================

*MAT_PIECEWISE_LINEAR_PLASTICITY

$# mid ro e pr sigy etan fail tdel

100 7.85e-06 210.0 0.3 0.9

$# c p lcss lcsr vp

500 1

$# eps1 eps2 eps3 eps4 eps5 eps6 eps7 eps8

$# es1 es2 es3 es4 es5 es6 es7 es8

$===============================================================================

$ BOUNDARY cards

$===============================================================================

*BOUNDARY_SPC_SET

$# nsid cid dofx dofy dofz dofrx dofry dofrz

1 0 1 1 1 1 1 1

*BOUNDARY_SPC_SET

$# nsid cid dofx dofy dofz dofrx dofry dofrz

2 0 0 1 1 1 1 1

*BOUNDARY_PRESCRIBED_MOTION_SET

$# nsid dof vad lcid sf vid death birth

2 1 2 1 40.0 0 1.0E28 0.0

$===============================================================================

$ DEFINE BOX cards

$===============================================================================

*PARAMETER_EXPRESSION

$ Patch size parameter

rxmin, -96

rxmax, 96

rymin, -24

rymax, 24

$ Box parameter

rbox1xmin, &xmin-1.0

rbox1xmax, &xmin+0.1

rbox1ymin, &ymin-1.0

rbox1ymax, &ymax+1.0

rbox2xmin, &xmax-0.1

rbox2xmax, &xmax+1.0

rbox2ymin, &ymin-1.0

rbox2ymax, &ymax+1.0

*DEFINE_BOX

$# boxid xmn xmx ymn ymx zmn zmx

1 &box1xmin &box1xmax &box1ymin &box1ymax -0.01 0.01

*DEFINE_BOX

$# boxid xmn xmx ymn ymx zmn zmx

2 &box2xmin &box2xmax &box2ymin &box2ymax -0.01 0.01

$===============================================================================

$ SET cards

$===============================================================================

*SET_NODE_GENERAL_TITLE

Clamping on the left (fixed)

$# sid da1 da2 da3 da4 solver

1 0.0 0.0 0.0 0.0 MECH

$# option e1 e2 e3 e4 e5 e6 e7

BOX 1 0 0 0 0 0 0

*SET_NODE_GENERAL_TITLE

Clamping on the right (translation)

$# sid da1 da2 da3 da4 solver

2 0.0 0.0 0.0 0.0 MECH

$# option e1 e2 e3 e4 e5 e6 e7

BOX 2 0 0 0 0 0 0

$===============================================================================

$ DEFINE CURVE cards

$===============================================================================

*DEFINE_CURVE_TITLE

prescribed motion curve

$# lcid sidr sfa sfo offa offo dattyp lcint

1 0 1.0 1.0 0.0 0.0 0 0

$# a1 o1

0.0 0.0

&te 1.0

1000000.0 1.0

*END

$===============================================================================

$ IGA Model (Geometry + Topology Information)

$===============================================================================

*KEYWORD

$===============================================================================

$ NODE cards (for nodal output)

$===============================================================================

*NODE

$# nid x y z tc rc

10001 -32.0 0.0

10002 32.0 0.0

$===============================================================================

$ IGA Points in parameter space

$===============================================================================

*IGA_POINT_UVW

$# pid nid u v w

1 10001 0.333333 0.5 0.0

2 10002 0.666667 0.5 0.0

$===============================================================================

$ IGA Point set cards

$===============================================================================

*SET_IGA_POINT_UVW

$# sid da1 da2 da3 da4 solver

101 0.0 0.0 0.0 0.0MECH

$# pid1 pid2 pid3 pid4 pid5 pid6 pid7 pid8

1 2 0 0 0 0 0 0

$===============================================================================

$ IGA 1D Boundary Representations (B-Rep loops)

$===============================================================================

*IGA_1D_BREP

$# brid

$# eid1 eid2 eid3 eid4 eid5 eid6 eid7 eid8

1 2 3 4 5 6 7 8

9 10 11 12 0 0 0 0

$===============================================================================

$ IGA Trimming Curves in parameter space

$===============================================================================

*IGA_1D_NURBS_UVW

$# patchid nr pr

1 2 1

$# unir

$# r1 r2 r3 r4

0.0 0.0 1.0 1.0

$# u v w wgt

1.0 0.0 0.0 1.0

1.0 1.0 0.0 1.0

*IGA_1D_NURBS_UVW

2 2 1

0.0 0.0 1.0 1.0

1.0 1.0 0.0 1.0

0.8333333 1.0 0.0 1.0

…

$===============================================================================

$ IGA Parametric Edges

$===============================================================================

*IGA_EDGE_UVW

$# eid exyzid patchid sense rstart rend

1 11 1 0 0.0 0.0

*IGA_EDGE_UVW

$# eid exyzid patchid sense rstart rend

2 10 2 1 0.0 0.0

…

$===============================================================================

$ IGA Physical Edges

$===============================================================================

*IGA_EDGE_XYZ

$# eid patchid ori pidstart pidend psid

1 0 0 0 0 0

*IGA_EDGE_XYZ

$# eid patchid ori pidstart pidend psid

2 0 0 0 0 0

…

$===============================================================================

$ IGA 2D NURBS Patch in physical space

$===============================================================================

*IGA_2D_NURBS_XYZ

$# patchid nr ns pr ps

1 54 15 2 2

$# unir unis

0 0

$# r1 r2 r3 r4

0.0 0.0 0.0 0.0192308

…

0.961859 0.9810898 1.0 1.0

1.0 0.0 0.0 0.0

$# s1 s2 s3 s4

0.0 0.0 0.0 0.0769765

…

0.7695513 0.8464743 0.9234508 1.0

1.0 1.0 0.0 0.0

$# x y z wgt

-96.0 24.0 0.0 1.0

-94.15385 24.0 0.0 1.0

-90.46026 24.0 0.0 1.0

-86.76667 24.0 0.0 1.0

-83.07307 24.0 0.0 1.0

-79.37949 24.0 0.0 1.0

…

$===============================================================================

$ IGA Physical Face

$===============================================================================

*IGA_FACE_XYZ

$# fid patchid ori psid esid

1 1 0 101 0

$# brid1 brid2 brid3 brid4 brid5 brid6 brid7 brid8

1 0 0 0 0 0 0 0

*END

IGA_tensile_test_input.zip