/STACK

Block Format Keyword This option is used to define the stacking sequence of a composite shell (/PROP/PCOMPP) in conjunction with the /STACK option.

Description

Two possible input:
  • All elements may have different number of plies by associating a group of elements to the ply in a way similar to OptiStruct.
  • The layout is described by a sequence of substacks ("SUB"), which are comprised of several plies. The interface between substacks is defined with INT option line.

The input can be either "substack" or by ply, but not both.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/STACK/stack_ID/unit_ID
stack_title
Ishell Ismstr Ish3n Idril     Z0    
hm hf hr dm dn
  Istrain Ashear   Iint   Ithick    
VX VY VZ skew_ID Iorth Ipos  
By ply (Each ply per two lines, see Example (Substack with /DRAPE))
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Pply_IDi ϕ   i Zi          
Blank
Or by substack (Each substack per two lines, see Example (Substack with /DRAPE))
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Sub Nsub Sub-plyn            
Substack Name
Pply_IDi ϕ   i Zi          
Blank
Sub Nsub Sub-plyn              
Substack Name
Pply_IDj ϕ j Zj          
Blank
Optional (Each connection between 2 substacks per line)
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
INT Pply_IDt Pply_IDb              

Definitions

Field Contents SI Unit Example
stack_ID Stack identifier

(Integer, maximum 10 digits)

  
unit_ID Unit Identifier

(Integer, maximum 10 digits)

  
stack_title Stack title

(Character, maximum 100 characters)

  
Ishell Shell element formulation flag. 2
= 0
Use value in /DEF_SHELL.
= 1 Default, if /DEF_SHELL is not defined
Q4, visco-elastic hourglass modes orthogonal to deformation and rigid modes (Belytschko).
=2
Q4, visco-elastic hourglass without orthogonality (Hallquist).
= 3
Q4, elasto-plastic hourglass with orthogonality.
= 4
Q4 with improved type 1 formulation (orthogonalization for warped elements).
= 12
QBAT shell formulation
= 24
QEPH shell formulation

(Integer)

  
Ismstr Shell small strain formulation flag. 3
= 0
Use value in /DEF_SHELL.
= 1
Small strain from time =0 (new formulation compatible with all other formulation flags).
= 2 Default, if /DEF_SHELL is not defined
Full geometric nonlinearities with possible small strain formulation activation in Radioss Engine (/DT/SHELL/CST).
= 4
Full geometric nonlinearities (in Radioss Engine, option /DT/SHELL/CST has no effect).

(Integer)

  
Ish3n 3 node shell element formulation flag.
= 0
Use value in /DEF_SHELL
= 1
Standard triangle (C0)
= 2 Default, if /DEF_SHELL is not defined
Standard triangle (C0) with modification for large rotation.
= 30
DKT18
= 31
DKT_S3, which based on DTK12 of BATOZ (refer to the Theory Manual)

(Integer)

  
Idril Drilling degree of freedom stiffness flag. 8
= 0
No
= 1
Yes

(Integer)

  
Z0 Distance from the shell element reference plane to the bottom surface of the shell (Real or blank).

It should be considered, if Ipos =2.

Default = 0.0 (Real)

  
hr Shell membrane hourglass coefficient. 4

Default = 0.01 (Real)

  
hf Shell out-of-plane hourglass.

Default = 0.01 (Real)

  
hr Shell rotation hourglass coefficient.

Default = 0.01 (Real)

  
dm Shell membrane damping.

For additional information, refer to Hourglass Resistance in the Theory Manual.

  • Default = 5% for LAW25
  • Default = 5% for Ishell=12 (QBAT)
  • Default = 1.5% for Ishell=24 (QEPH) + LAW36 and LAW43

(Real)

  
dn Shell numerical damping. 5
It only used for Ishell =12 and 24
  • Default =1.5% for Ishell =24 (QEPH)
  • Default =0.1% for Ishell =12 (QBAT)
  • Default =0.01% for Ish3n =30 (DKT18)

(Real)

  
Istrain Compute strains for post-processing flag.
= 0 (Default)
Use value in /DEF_SHELL
= 1
Yes
= 2 Default, if /DEF_SHELL is not defined
No

(Integer)

  
Ashear Shear factor

Default is Reissner value: 5/6 (Real)

  
Iint Thickness integration formulation - through ply thickness. 1
= 1 (Default)
Uniform integration scheme (uniformly distribution of the integration points through ply thickness).
= 2
Gauss integration scheme.

(Integer)

  
Ithick Shell resultant stresses calculation flag.
= 0 (Default)
Use value in /DEF_SHELL
= 1
Thickness change is taken into account
= 2 Default, if /DEF_SHELL is not defined
Thickness is constant

(Integer)

  
VX X component for reference vector 9

Default = 1.0 (Real)

  
VY Y component for reference vector

Default = 0.0 (Real)

  
VZ Z component for reference vector

Default = 0.0 (Real)

  
Skew_ID Skew identifier for reference vector. 9

If the local skew is defined, its X-axis replaces the global vector V. VX, VY, and VZ coordinates are ignored.

Default = 0 (Integer)

  
Iorth Orthotropic system formulation flag for reference vector.
= 0 (Default)
The first axis of orthotropy is maintained at constant angle with respect to the X-axis of an orthonormal co-rotational element coordinate system.
= 1
The first orthotropy direction is constant with respect to a non-orthonormal system of deformed element.

(Integer)

  
Ipos Ply positioning flag for reference vector. 10
= 0 (Default)
Ply positions are automatically calculated with regard to ply thicknesses. The coherence of global thickness with the sum of ply thicknesses is automatically checked.
= 1
All ply positions in the element thickness are user-defined. Multiple plies may have the same special position. Global thickness is not checked in this case since it needs to not be equal to sum of ply thicknesses.
=2
The shell element reference plane is at Z0 from the bottom surface of the shell.
=3
The top surface of the shell is considered as element reference plane.
=4
The bottom surface of the shell is considered as element reference plane.

(Integer)

  
Pply_IDi Ply identifier for ply i.

(Integer)

i =1, 2, 3 ...N

  
ϕ  i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqGqFfpeea0xe9vq=Jb9 vqpeea0xd9q8qiYRWxGi6xij=hbba9q8aq0=yq=He9q8qiLsFr0=vr 0=vr0db8meaabaqaciGacaGaaeqabaWaaeaaeaaakeaacqaHvpGzda WgaaWcbaGaaGPaVlaadMgaaeqaaaaa@3BD4@ Angle for ply i. 9

(Real)

 [ deg ]
Zi, Z position of ply i (Zi or defines the position of the middle of the ply).

Default = 0.0 (Real)

 [ m ]
Sub =SUB: Indicates the beginning of a substack definition (must be left justified). 11

(Integer)

  
Nsub Substack identification number

(Integer)

  
Sub-plyn Number of plies in substack

(Integer)

  
Substack Name Name of the substack

(Maximum 100 characters)

  
INT Indicates the connection between 2 substacks (must be left justified).

(Integer)

  
Pply_IDt Ply identification number of the top ply of the bottom substack. One of ply ID in Pply_IDi or Pply_IDj

(Integer)

  
Pply_IDb Ply identification number of the bottom ply of the top substack. One of ply ID in Pply_IDi or Pply_IDj

(Integer)

  

Example (Substack with /DRAPE)

Substack definition for the ply layout with /DRAPE.

prop_type17_example
Figure 1. 
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
Mg                  mm                   s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PROP/PCOMPP/1/1
PCOMPP example
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/STACK/1/1
NEW_PROP_1
#   Ishell    Ismstr     Ish3n     Idril                                      Z0
        12         0         0         0                                       0
#                 hm                  hf                  hr                  dm                  dn
                   0                   0                   0                   0                   0
#            Istrain              Ashear                Iint              Ithick
                   0                   0                   1                   0
#                 VX                  VY                  VZ   skew_ID     Iorth      Ipos           
                   0                   1                   0         0         0         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#      Sub      Nsub  Sub-plyn
SUB                1         4
# Substack Name
TOP
# Pply_IDi                PHIi                  Zi 
        11                  45                   0           
# Pply_IDi                PHIi                  Zi       
        12                 -45                   0         
# Pply_IDi                PHIi                  Zi   
        13                  90                   0         
# Pply_IDi                PHIi                  Zi     
        14                  90                   0           
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#      Sub      Nsub  Sub-plyn
SUB                2         4
# Substack Name
LEFT
# Pply_IDi                PHIi                  Zi         
        21                  45                   0         
# Pply_IDi                PHIi                  Zi         
        22                 -45                   0         
# Pply_IDi                PHIi                  Zi       
        23                  90                   0       
# Pply_IDi                PHIi                  Zi       
        24                  90                   0         
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#      Sub      Nsub  Sub-plyn
SUB                3         4
# Substack Name
RIGHT
# Pply_IDi                PHIi                  Zi          
        31                  45                   0       
# Pply_IDi                PHIi                  Zi         
        32                 -45                   0       
# Pply_IDi                PHIi                  Zi         
        33                  90                   0       
# Pply_IDi                PHIi                  Zi         
        34                  90                   0       
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#      Sub      Nsub  Sub-plyn
SUB                4         3
# Substack Name
MIDDLE
# Pply_IDi                PHIi                  Zi         
        41                  45                   0           
# Pply_IDi                PHIi                  Zi       
        42                 -45                   0       
# Pply_IDi                PHIi                  Zi         
        43                  90                   0       
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#      Int  Pply_IDt  Pply_IDb
INT               14        21
INT               14        31
INT               43        21
INT               34        41
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/11/1
Part number 11
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i  
         4                  .5                  45        45         0         0                   0 
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/12/1
Part number 12
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i 
         4                  .5                  45        45         0         0                   0 
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/13/1
Part number 13
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        45         0         0                   0 
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/14/1
Part number 14
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        45         0         0                   0 
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/21/1
Part number 21
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i        
         4                  .5                  45        46         0         0                   0
# drape_ID  def_orth
         0         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/22/1
Part number 22
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        46         0         0                   0
# drape_ID  def_orth 
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/23/1
Part number 23
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i     
         4                  .5                  45        46         0         0                   0
# drape_ID  def_orth 
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/24/1
Part number 24
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i     
         4                  .5                  45        46         0         0                   0
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/31/1
Part number 31
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        47         0         0                   0
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/32/1
Part number 32
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        47         0         0                   0
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/33/1
Part number 33
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i     
         4                  .5                  45        47         0         0                   0
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/34/1
Part number 34
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        47         0         0                   0
# drape_ID  def_orth
         1         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/41/1
Part number 41
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i   
         4                  .5                  45        44         0         0                   0 
# drape_ID  def_orth
         2         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/42/1
Part number 42
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i 
         4                  .5                  45        44         0         0                   0 
# dr ape_ID  def_orth
          2         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PLY/43/1
Part number 43
# mat_ID_i                   t           delta_phi  grsh4n_I  grsh3n_I   Npt_ply                 A_i 
         4                  .5                  45        44         0         0                   0 
# drape_ID  def_orth
         2         2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/DRAPE/1
drape in shell group 1
#   Entity Entity_ID            Thinning         Theta_drape 
SHELL              2                                     45.
SHELL              3                                     45.
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/DRAPE/2
drape in shell group 2
#   Entity Entity_ID            Thinning         Theta_drape 
SHELL              1                                    -45.
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/SHELL/3
1     43131     43138     43137     43132                                                 0
2     43132     43133     43136     43137                                                 0
3     43134     43132     43137     43135                                                 0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
Using option def_orth =2 to define material direction for each ply.

stack_def_orth_option
Figure 2.

Comments

  1. The stack is used in combination with /PLY to create composites properties through the ply-based definition. It is NOT compatible with /PROP/TYPE19 (PLY) option.
    • Each ply in the stack is defined using Pply_IDi or Pply_IDj and can only be referenced once in the stack. If ply ids are used more than once an error message will output.
    • Each ply of a shell element can contain a different (≥ 1) number of integration points through its ply thickness. i.e. Npt_ply =3 in /PLY.
    • Different integration scheme (uniformly distribution or Gauss integration scheme) could be defined with option Iint inside this property,
  2. Ishell, Ish3n – 4-node and 3-node shell formulation flag.
    • Ishell =1,2,3,4 (Q4): original 4 nodes Radioss shell with hourglass perturbation stabilization.
    • Ishell =24 (QEPH): formulation with hourglass physical stabilization for general use.
    • Ishell =12 (QBAT): modified BATOZ Q4γ24 shell with four Gauss integration points and reduced integration for in-plane shear. No hourglass control is needed for this shell.
    • Ish3n =30 (DKT18): BATOZ DKT18 thin shell with three Hammer integration points.
    • The hourglass formulation is visco-elastic for Q4 shells.
  3. Ismstr - Small strain formulation
    • Small strain formulation is activated from time t = 0, if Ismstr=1. It may be used for a faster preliminary analysis, but the accuracy of results is not ensured. Any shell for which Δ t < Δ t min can be switched to a small strain formulation by Radioss Engine option /DT/SHELL/CST.
    • If Ismstr=1, the strains and stresses which are given in material laws are engineering strains and stresses; otherwise they are true strains and stresses.
  4. hm, hf, and hr - hourglass coefficients
    • hm, hf, and hr are only used for Q4 shells. They must have a value between 0 and 0.05.
    • For Ishell = 3, default values for hm and hr are 0.1.
  5. dn - Shell numerical damping
    It is only used for Ishell =12 or 24:
    • for Ishell =24, dn is used for hourglass stress calculation
    • for QBAT, dn is used for all stress terms, except transverse shear
    • for DKT18, dn is only used for membrane
  6. Ithick - Shell resultant stresses calculation flag.
    • If Ithick= 1, the small strain option is automatically deactivated in the corresponding type of element
  7. Output for post-processing
    • Flag Istrain is automatically set to 1 for LAW25
  8. Idril - Drilling degree of freedom stiffness
    • Drilling DOF stiffness is recommended for implicit solutions especially for Riks method and bending dominated problems
    • Idril is available for QEPH, QBAT (Ishell =12, 24), and standard triangle (C0) shell elements (Ish3n = 1, 2).
  9. Anisotropy in local coordinate system.
    Two different ways to define the anisotropy direction with this property.
    • skew_ID=0:Anisotropy direction defined with global vector V MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOvaaaa@36D5@ (components defined in Line 6) and angle ϕ i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqy1dy2aaS baaSqaaiaadMgaaeqaaaaa@38D9@ (angle in degree) for each ply.
    • skew_ID ≠ 0: Anisotropy direction defined with skew (X-axis in skew replaces the global vector V MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOvaaaa@36D5@ ) and angle ϕ i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqy1dy2aaS baaSqaaiaadMgaaeqaaaaa@38D9@ (angle in degree) for each ply.
    • For both ways (with vector V MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOvaaaa@36D5@ or with skew), Projection of vector V MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOvaaaa@36D5@ (or x-axis of skew) on shell element plane becomes the vector V ′ . Then for each ply, the first anisotropic direction (direction 1) is vector V ′ turn ϕ i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqy1dy2aaS baaSqaaiaadMgaaeqaaaaa@38D9@ degrees (turns positive direction coding to shell normal n MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOBaaaa@36ED@ ).


      Figure 3.
    • α   i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqGqFfpeea0xe9vq=Jb9 vqpeea0xd9q8qiYRWxGi6xij=hbba9q8aq0=yq=He9q8qiLsFr0=vr 0=vr0db8meaabaqaciGacaGaaeqabaWaaeaaeaaakeaacqaHXoqyda WgaaWcbaGaaGPaVlaadMgaaeqaaaaa@3BAB@ is the angle between local anisotropic direction 1 and 2 (directions of anisotropy) for each ply which defined in /PLY. If α   i = 90 ∘ MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqGqFfpeea0xe9vq=Jb9 vqpeea0xd9q8qiYRWxGi6xij=hbba9q8aq0=yq=He9q8qiLsFr0=vr 0=vr0db8meaabaqaciGacaGaaeqabaWaaeaaeaaakeaacqaHXoqyda WgaaWcbaGaaGPaVlaadMgaaeqaaOGaeyypa0JaaGyoaiaaicdadaah aaWcbeqaaiablIHiVbaaaaa@3F9F@ , then ply is in orthotropic.
  10. Ipos - ply position
    • In this property, ply position defined with Z i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ and option Ipos.
    • Z i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ values are real ply positions in the local Z axis (negative and positive value are allowed and Z i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ defines the position of the middle of the each ply).
    • Z 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ only used with Ipos=2, it indicated distance from the shell element reference middle surface to the bottom surface of the whole ply or stack. For additional information, see Ipos=2
    • Ipos = 0: ply positions are automatically calculated with regard to ply thicknesses.
      • The input thickness “Thick” may be equal to zero as the true shell thickness is always calculated from the ply thicknesses and positions of ply defined by Z i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ .
      • If the input thickness “Thick” is different from 0.0, a warning will be displayed if the calculated thickness from the plies is different from the input thickness.


        Figure 4.
    • Ipos = 1: All ply positions and thickness in the element are user-defined (with in /PLY and Z i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ ).
      • Global thickness “Thick” is not checked, as it does not need to be equal to the sum of ply thickness
      • Multiple plies are allowed to have the same space position
      • This option is not recommended unless the number of ply is constant for all elements
    • Ipos = 2: the shell element mid-surface is at Z 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOwamaaBa aaleaacaWGPbaabeaaaaa@37F0@ from the bottom of the ply layout.


      Figure 5.
    • Ipos = 3: the top of the ply layout is coincident with the element mid-surface.


      Figure 6.
    • Ipos = 4: the bottom of the ply layout is coincident with the element mid-surface.


      Figure 7.
  11. Define by substack.
    • If the substack definition is used, each substack definition begins with the keyword "SUB" and the substack identification number.
    • All the plies until the next keyword "SUB" or the keyword "INT" is encountered belong to the same substack.
    • All substacks must be defined before defining the “INT connections
    • If an element contains plies belonging to several substacks, the connection between the substacks is defined with an “INT” connection: the ply Pply_IDt of the first substack is connected to the ply Pply_IDb of the second substack.
    • For additioinal inforation, refer to the above examples for this property.
  12. Material for each ply.
    • Material for each ply defined with mat_ID in /PLY.
    • Different material laws could be defined for each ply.
    • The material law number given in /PART will be used to define the mass and the sound speed of the composite, as well as the interface stiffness.