/MAT/LAW59 (CONNECT)

Block Format Keyword This law describes the Connection material, which can be used to model spotweld, welding line, glue, or adhesive layers in laminate composite material.

Elastic and elastoplastic behavior in normal and shear directions can be defined. The curves that represent plastic behavior can be specified for different displacement rates. This material is applicable only to solid hexahedron elements (/BRICK) and the material time-step does not depend on element height.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/MAT/LAW59/mat_ID/unit_IDor /MAT/CONNECT/mat_ID/unit_ID
mat_title
ρ i                
E G Imass Icomp Ecomp  
Nb_fct Fsmooth Fcut            
If Nb_fct > 0, each true plastic stress vs. displacement functions in normal/tangent direction per line
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Y_fct_IDN Y_fct_IDT SRref Fscaleyld        

Definitions

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer, maximum 10 digits)

 
unit_ID Unit Identifier.

(Integer, maximum 10 digits)

 
mat_title Material title.

(Character, maximum 100 characters)

 
ρ i Density.

(Real)

[ kg m 3 ]
E Young's modulus in the normal direction per unit length.

(Real)

[ Pa m ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeaaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada WcaaqaaiaadcfacaWGHbaabaGaamyBaaaaaiaawUfacaGLDbaaaaa@3AA3@
G Shear modulus in the tangential direction per unit length.

(Real)

[ P a m ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeaaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada WcaaqaaiaadcfacaWGHbaabaGaamyBaaaaaiaawUfacaGLDbaaaaa@3AA3@
Imass Mass calculation flag.
= 0 (Default)
Element mass is calculated using density and volume.
= 1
Element mass is calculated using density and (means of upper and lower) area.

(Integer)

 
Icomp Symmetric elasto-plastic behavior in compression.
= 0
Symmetric elasto-plastic behavior in tension and compression.
= 1
Elasto-plastic behavior defined by input yield function in tension only.
 
Ecomp Compression modulus per unit length.

Default = E

[ P a m ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeaaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada WcaaqaaiaadcfacaWGHbaabaGaamyBaaaaaiaawUfacaGLDbaaaaa@3AA3@
Nb_fct Number of input functions: true stress vs plastic displacement (normal or tangential).
= 0
Material is linear elastic.

(Integer)

 
Fsmooth Displacement rate filtering flag.
= 0 (Default)
No displacement rate filtering.
= 1
Displacement rate filtering.

(Integer)

 
Fcut Cutoff frequency for the displacement rate filtering.

Default = 1030 (Real)

[Hz]
Y_fct_IDN True plastic stress vs. displacement in normal direction defined for the reference displacement rate.

(Integer)

 
Y_fct_IDT True plastic stress vs. displacement in tangential direction defined for the reference displacement rate.

(Integer)

 
SRref Displacement rate values for which the set of functions are defined.

Default = 0.0 (Real)

[ 1 s ]
Fscaleyld Scale factor for the plastic stress.

Default = 1.0 (Real)

[ Pa ]

Example (Spotweld)

#RADIOSS STARTER
/UNIT/1
unit for mat
                  Mg                  mm                   s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/LAW59/1/1
spotweld
#              RHO_I
              7.9E-9
#                  E                   G     Imass     Icomp               Ecomp
               21000               21000         0         0                   0
# NB_funct   Fsmooth                Fcut
         1         1                   0
# YFun_IDN  YFun_IDT        SR_reference        Fscale_yield
         1         2                   0                   0
/FAIL/CONNECT/1
#          EPS_MAX_N               EXP_N             ALPHA_N R_fct_IDN     Ifail  Ifail_so      ISYM
                   1                   0                   0         0         0         1         0
#          EPS_MAX_T               EXP_T             ALPHA_T R_fct_IDT
                 1.8                   0                   0         0
#              EIMAX               ENMAX               ETMAX                  Nn                  Nt
                   0                   0                   0                   0                   0
#               Tmax               Nsoft           AREAscale
                   0                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  3. FUNCTIONS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/1
New_function
#                  X                   Y
                   0                 250                                                            
                   1                 350                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/2
New_function
#                  X                   Y
                   0                 350                                                            
                   1                 350                                                            
#---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 law is compatible with 8-noded hexadedron elements (/BRICK) only. It is only compatible with /PROP/TYPE43.
  2. The stiffness modulus and stresses are defined per displacement in order to be independent from the initial height of the solid element.

    For example, E MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGfbaaaa@39A1@ =210000 MPa/mm means that the normal stress increases by 210000 MPa for each 1 mm of displacement until the yield stress limit specified by the yield stress curve is reached.

  3. The complete element displacement u ¯ MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyDayaara aaaa@3708@ can be subdivided into an elastic portion u ¯ e MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyDayaara WaaWbaaSqabeaacaWGLbaaaaaa@381F@ (before yield stress is reached) and a portion of the plastic displacement u ¯ p l MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyDayaara WaaWbaaSqabeaacaWGWbGaamiBaaaaaaa@391B@ . Plastic displacement is calculated as:
    Normal plastic displacement:(1)
    u ¯ n p l = u ¯ n u ¯ n e = u ¯ n σ n t r u e E MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyDayaara Waa0baaSqaaiaad6gaaeaacaWGWbGaamiBaaaakiabg2da9iqadwha gaqeamaaBaaaleaacaWGUbaabeaakiabgkHiTiqadwhagaqeamaaDa aaleaacaWGUbaabaGaamyzaaaakiabg2da9iqadwhagaqeamaaBaaa leaacaWGUbaabeaakiabgkHiTmaalaaabaGaeq4Wdm3aa0baaSqaai aad6gaaeaacaWG0bGaamOCaiaadwhacaWGLbaaaaGcbaGaamyraaaa aaa@4D35@
    Shear plastic displacement:(2)
    u ¯ s p l = u ¯ s u ¯ s e = u ¯ s σ s t r u e E MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyDayaara Waa0baaSqaaiaadohaaeaacaWGWbGaamiBaaaakiabg2da9iqadwha gaqeamaaBaaaleaacaWGZbaabeaakiabgkHiTiqadwhagaqeamaaDa aaleaacaWGZbaabaGaamyzaaaakiabg2da9iqadwhagaqeamaaBaaa leaacaWGZbaabeaakiabgkHiTmaalaaabaGaeq4Wdm3aa0baaSqaai aadohaaeaacaWG0bGaamOCaiaadwhacaWGLbaaaaGcbaGaamyraaaa aaa@4D4E@

    Total normal (shear) displacement is the sum of plastic normal (shear) displacement and elastic normal (shear) displacement.

    The plastic displacement is accounted for when the normal and tangent yield stress curves are specified. These are usually non-decreasing functions, which represent true stress as a function of the plastic displacement either in normal or in shear direction. The first abscissa value of the function should be "0" and the first ordinate value is the yield stress. The functions may have a stress decrease portion to model material damage.

  4. If Icomp =0, the material behavior is elasto plastic in both tension and compression, the compression modulus is given by Ecomp (which by default is equal to E MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGfbaaaa@39A1@ ).

    If Icomp =1, the material is nonlinear elasto plastic in tension and linear in compression. The compression modulus is given by Ecomp. The normal and shear degrees of freedom are uncoupled and the shear behavior is always symmetrical.

  5. The height of the solid element can be equal to zero.
  6. All nodes of the solid elements must be connected to other shells or solid elements, secondary nodes of rigid body (/RBODY) or secondary nodes of tied interface (/INTER/TYPE2).
  7. When all nodes of the solid element become free, the element is deleted.
  8. The rupture criteria for this material are defined by /FAIL/CONNECT.