Образование "шейки" в образце для испытаний на разрыв при пластическом деформировании в (2D)

Ниже приведен скрипт для расчета

reset
create vertex 0 0 0
create vertex 0.004 0 0
create vertex 0.004 0.016 0
create vertex 0 0.016 0
create vertex 0 0.024 0
create vertex 0.008 0.024 0
create vertex 0 0.03 0
create vertex 0.008 0.03 0
create vertex 0.014 0.016 0
create curve vertex 1 2  
create curve vertex 4 3  
create curve vertex 5 6  
create curve vertex 7 8  
create curve vertex 1 4  
create curve vertex 11 5  
create curve vertex 13 7  
create curve vertex 2 3  
create curve vertex 6 8  
create curve arc center vertex 9  18  17  
merge vertex all 
create surface curve 2 8 1 5  
create surface curve 12 6 3 10  
create surface curve 15 7 4 9  
merge curve all 
surface 1 2 3  size auto factor 5
mesh surface 1 2 3 
create material 1
modify material 1 name 'Steel'
modify material 1 set property 'POISSON' value 0.3
modify material 1 set property 'MODULUS' value 7.8e+10
modify material 1 set property 'MISES_YIELD_STRENGTH' value 3.5e+08
modify material 1 set property 'ISO_ULTIMATE_STRENGTH' value 4.95e+08
modify material 1 set property 'ULTIMATE_STRAIN' value 1
set duplicate block elements off
block 1 add surface all
block 'Block 1' material 1 cs 1 element plane order 1
create displacement  on curve 7 6 5  dof 1 fix  
create displacement  on curve 1  dof 2 fix  
create displacement  on curve 4 9  dof 2 fix 0.002 
analysis type static findefs elasticity plasticity dim2 planestrain
calculation start path 'C:/Users/User/Documents/CAE-Fidesys-4.1/fidesys01.pvd'