/MAT/LAW119 (SH_SEATBELT)

Block Format Keyword This orthotropic shell material is designed for 2D seatbelt element.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/MAT/LAW119/mat_ID/unit_ID or /MAT/SH_SEATBELT/mat_ID/unit_ID
mat_title
M Lmin            
K C RE        
fct_ID1 fct_ID2 Fscale1 Fscale2        
E22 ν MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqyVd4gaaa@378E@ 12 G12 Fscale22    
Ec ν c MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqyVd42aaS baaSqaaiaadogaaeqaaaaa@38A2@ Tc        

Definitions

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer, maximum 10 digits)
unit_ID (Optional) Unit identifier.

(Integer, maximum 10 digits)
mat_title Material title.

(Character, maximum 100 characters)
M Mass per unit length of the seatbelt.

(Real)

 [ kg m ]
Lmin Minimum length. Only used with /SLIPRING/SHELL.

(Real)

 [ m ]
K Linear loading and unloading stiffness per unit length.

Used only if f c t _ I D   1 i = 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqGqFfpeea0xe9vq=Jb9 vqpeea0xd9q8qiYRWxGi6xij=hbba9q8aq0=yq=He9q8qiLsFr0=vr 0=vr0db8meaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGMbGaam 4yaiaadshacaGGFbGaamysaiaadseadaWgaaWcbaGaaeiiaiaaigda caWGPbaabeaakiabg2da9iaaicdaaaa@40F0@ .

(Real)

 [ N ]
C Linear Damping coefficient per unit length

If not defined, a small amount of damping is automatically applied.

(Real)

 [ Ns ] MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaaca WGobGaam4CaaGaay5waiaaw2faaaaa@39B4@
RE Reduction factor value for compression behavior.

Minimum value, RE > 0.001.

Default =1.0 (Real)

  
fct_ID1 Function identifier defining loading force versus engineering strain or table identifier for set of strain rate dependent loading curve f(ε).

(Integer)

  
fct_ID2 Function identifier defining unloading force versus engineering strain f(ε).

Not used when element is inside slipring or retractors.

(Integer)

  
Fscale1 Scale factor for f(ε) for fct_ID1.

Default = 1.0 (Real)

 [ N ]
Fscale2 Scale factor for f(ε) for fct_ID2.

Default = 1.0 (Real)

 [ N ]
E22 Young’s modulus in transverse direction. 8

(Real)

 [ Pa ]
ν MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqyVd4gaaa@378E@ 12 Poisson’s ratio.

Default = 0.2 (Real)

  
G12 Shear modulus. 9

(Real)

 [ Pa ]
Fscale22 Stiffness scaling factor for transverse direction.

Not used in current version.

Default = 0.0 (Real)

  
Ec Young’s modulus for coating layer.

Not used in current version.

Default = 0.0 (Real)

 [ Pa ]
ν c MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqyVd42aaS baaSqaaiaadogaaeqaaaaa@38A2@ Poisson’s ratio for coating layer.

Not used in current version.

Default = ν MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqyVd4gaaa@378E@ 12 (Real)

  
Tc Thickness for coating layer.

Not used in current version.

(Real)

 [ m ]

Example

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
Seatbelt
                  Mg                  mm                   s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/SH_SEATBELT/1/1
Seatbelt
#            Density                Lmin
                1E-6                   0    
#              KTens               CTens                  RE
               10000                 1.1                 1.0
#  fct_ID1   fct_ID2             Fscale1             Fscale2
         0         0                   0                   0
#                E22                NU12                 G12            Fscale22
                   0                   0                   0                   0
#                 Ec                 NUC                  TC
                   0                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

  1. This material law is orthotropic and can only be used with /PROP/TYPE9 (SH_ORTH). The seatbelt main direction is direction 1 and the transverse direction is direction 2. Seatbelt main (direction 1) is defined from node 1 and node 2 of the shell element. Any other way to define orthotropy directions in /PROP/TYPE9 is not taken into account.
  2. A 2D seatbelt element is, in fact, a combination of seatbelt springs elements and seatbelt shells. The longitudinal stiffness is mainly carried by springs (99%), whereas transverse stiffness is carried by the shells. The springs are automatically generated on the edges of the shell elements corresponding to the seatbelt main direction (direction 1). If an edge is common to 2 shells, then only 1 spring is generated.


    Figure 1.
  3. The tension behavior can be defined either as linear elastic, if K > 0 or nonlinear fct_ID1= 0. It corresponds to the total stiffness of the seatbelt.
  4. fct_ID2 is used for the unloading and reloading of the seatbelt. If fct_ID2 is not defined (fct_ID2 > 0), fct_ID1 is also used for unloading and reloading.
  5. fct_ID1 and fct_ID2 must be defined for positive strain only.
  6. The stiffness per unit length is the stiffness of the whole seatbelt. It is internally computed as a Young's modulus using the section of the seatbelt that is automatically computed. As the section (width * thickness) of the belt is internally computed, the same material can not be applied to several seatbelts having different sections.
  7. The seatbelt Young's modulus is automatically computed from the input stiffness defined in the seatbelt direction (either by K or the maximum slop of the curve fct_ID1 if defined).
  8. Default value for transversal modulus E22 is defined a percentage of stiffness of the belt.(1)
    E 22 = 0.1 ⋅ ( K seatbelt section ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbiqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyramaaBa aaleaacaaIYaGaaGOmaaqabaGccqGH9aqpcaaIWaGaaiOlaiaaigda cqGHflY1daqadaqaamaalaaabaGaam4saaqaaiaabohacaqGLbGaae yyaiaabshacaqGIbGaaeyzaiaabYgacaqG0bGaaeiiaiaabohacaqG LbGaae4yaiaabshacaqGPbGaae4Baiaab6gaaaaacaGLOaGaayzkaa aaaa@4EE9@
  9. Default value for shear modulus is defined as a small percentage of stiffness of the belt.(2)
    G 12 = 0.01 2 ⋅ ( 1 + ν 12 ) ⋅ ( K seatbelt section ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbiqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4ramaaBa aaleaacaaIXaGaaGOmaaqabaGccqGH9aqpdaWcaaqaaiaaicdacaGG UaGaaGimaiaaigdaaeaacaaIYaGaeyyXIC9aaeWaaeaacaaIXaGaey 4kaSIaeqyVd42aaSbaaSqaaiaaigdacaaIYaaabeaaaOGaayjkaiaa wMcaaaaacqGHflY1daqadaqaamaalaaabaGaam4saaqaaiaabohaca qGLbGaaeyyaiaabshacaqGIbGaaeyzaiaabYgacaqG0bGaaeiiaiaa bohacaqGLbGaae4yaiaabshacaqGPbGaae4Baiaab6gaaaaacaGLOa Gaayzkaaaaaa@5945@
  10. Minimum length Lmin is used only in case of sliprings (/SLIPRING/SHELL) to prevent stiffness becoming infinite and causing the time step to drop.