/MAT/LAW114 (SPR_SEATBELT)

Block Format Keyword This spring material is designed for 1D seatbelt elements.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/MAT/LAW114/mat_ID/unit_ID or /MAT/SPR_SEATBELT/mat_ID/unit_ID
mat_title
ρ Lmin
K C
fct_load fct_uload Xscale Fscale
E I J Fmax Mmax
AS R

Definition

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)

ρ Density.

(Real)

[ kg m 3 ]
Lmin Minimum length for mass computation.

Default = 1% of average mesh size (Real)

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

Used only if fct_load is not defined.

(Real)

[ N ]
C Damping.

If not defined, a small amount of damping is automatically applied. 9

(Real)

[ Ns ] MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaaca WGobGaam4CaaGaay5waiaaw2faaaaa@39B4@
fct_load Function identifier defining loading force versus engineering strain f ( ε ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaeqyTdugacaGLOaGaayzkaaaaaa@39F1@ .

(Integer)

fct_uload Function identifier defining unloading force versus engineering strain f ( ε ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaeqyTdugacaGLOaGaayzkaaaaaa@39F1@ .

Not used when element is inside slipring or retractors.

(Integer)

Xscale Scale factor for ε for fct_load and fct_uload.

Default = 1.0 (Real)

Fscale Scale factor for f ( ε ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaeqyTdugacaGLOaGaayzkaaaaaa@39F1@ for fct_load and fct_uload.

Default = 1.0 (Real)

[ N ]
E Young's modulus for compression and bending.

(Real)

[ Pa ]
I Area moment of inertia bending.

(Real)

[ m 4 ]
J Area moment of inertia torsion.

(Real)

[ m 4 ]
Fmax Maximum force for shear and compression.

(Real)

[ N ]
Mmax Maximum moment for bending and torsion.

(Real)

[ Nm ]
AS Shear area.

(Real)

[ m 2 ]
R Scaling factor for inertia.

Default = 1.0 (Real)

Example (Seatbelt)

#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/SPR_SEATBELT/1/1
Seatbelt
#            Density                Lmin
                1E-6                   0    
#              KTens               CTens
               10000                 1.1
# fct_load fct_uload              Xscale              Fscale
         0         0                   0                   0
#                  E                   I                   J                FMAX                MMAX
                   0                   0                   0                   0                   0
#                 AS                   R
                   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. The tension behavior can be defined as linear elastic if K > 0 and fct_load = 0.
  2. Loading curve (fct_load > 0) is used both for loading and unloading when unloading curve is not defined (fct_uload = 0).
  3. By default, there is no compression, so function fct_load and fct_uload must be input only for positive strain.
  4. The behavior in compression can be defined with Young's modulus (E), in that case the behavior can only be perfectly plastic, maximum force being defined by Fmax.
  5. Bending and torsion behavior are also defined using Young's modulus, area and area of inertia. The behavior is perfectly plastic.
  6. When the seatbelt element is inside a retractor or a slipring, unloading curve is not used.
  7. Damping is not applied when the element is inside a slipring and retractor.
  8. Minimum length is used only in case of sliprings (/SLIPRING/*) and retractors (/RETRACTOR/*) to prevent stiffness becoming infinite.
  9. It is recommended to use damping for seatbelts. If C = 0, a small amount of critical damping is automatically applied.