CNTSTB

Bulk Data Entry Defines parameters for stabilization control of contact (S2S and N2S) and gap elements (CGAP/CGAPG). This entry is supported with nonlinear static and nonlinear transient analysis types for both small and large displacement cases.

A CNTSTB Bulk Data Entry should be referenced by a CNTSTB Subcase Information entry to be applied in a particular subcase.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CNTSTB ID   APSTB LMTGAP   S0 S1    
  SCALE TFRAC              
The following continuation line (beginning with the CNTINT flag) is used to define another set of stabilization parameters, which overrides the set of parameters above, and applied locally on a specific contact interface (CTID). It can be repeated as required.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
  CNTINT CTID APSTB LMTGAP   SO S1    
  SCALE TFRAC              
The continuation line can also be used to define a set of stabilization parameters for CGAP/CGAPG elements with gap property (PID).
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
  GAPINT PID APSTB LMTGAP   SO S1    
  SCALE TFRAC              

CNTINT and GAPINT continuation lines can coexist in one CNTSTB card. CTID and PID can be identical in one CNTSTB card, as well.

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CNTSTB 99   NO            
  CNTINT 51 YES            
    0.01              
  CNTINT 52 YES            
  10.0 0.01              
  GAPINT 52 YES            
  1.0E4 0.25              
  GAPINT 58 YES     1.0 0.001    
  1.0E4 0.05              

Definitions

Field Contents SI Unit Example
ID Each CNTSTB Bulk Data Entry should have a unique identification number.

No default (Integer > 0)

 
APSTB Head flag indicating if contact stabilization is activated.
YES
Contact stabilization effect is activated.
NO (Default)
Contact stabilization effect is deactivated.
Note: All the fields following APSTB should be blank, if APSTB is set to NO.
 
LMTGAP Contact opening threshold for stabilization. Stabilization becomes zero when contact opening is greater than or equal to this value.
blank (Default for CNTINT continuation line)
The threshold is calculated automatically based on characteristic edge lengths at the contact surfaces. The default threshold is 1.0 for the GAPINT continuation line.

There is no default for the GAPINT continuation line. You are required to provide a value for LMTGAP field, if the GAPINT continuation line is specified.

(Real > 0.0 - specified threshold value)

 
S0 Scale factor for stabilization coefficient at the start of a subcase.

Default = 1.0 (Real ≥ 0.0)

 
S1 Scale factor for stabilization coefficient at the end of a subcase.

Default = 0.0 (Real ≥ 0.0)

 
SCALE Stabilization coefficient scale factor.

Default = 1.0 (Real ≥ 0.0)

 
TFRAC Factor for scaling tangential stabilization with respect to normal stabilization.

Default = 0.1 (Real ≥ 0.0)

 
CNTINT Defines the start of a continuation line used to specify another set of stabilization parameters, which overrides the set of parameters defined above, for a specific contact interface (CTID). It can be repeated as required.  
CTID Contact interface identification number.

No default (Integer > 0)

 
GAPINT Defines the start of a continuation line used to specify another set of stabilization parameters, which overrides the set of parameters defined above, for specific CGAP/CGAPG elements (PID). It can be repeated as required.  
PID Gap property identification number.

No default (Integer > 0)

 

Comments

  1. The CNTSTB Bulk Data Entry is selected by the CNTSTB Subcase Information Entry.
  2. When APSTB is YES, the contact normal stabilization stiffness K CSTB normal MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaDa aaleaacaqGdbGaae4uaiaabsfacaqGcbaabaGaaeOBaiaab+gacaqG YbGaaeyBaiaabggacaqGSbaaaaaa@3FC7@ is calculated as:(1)
    K CSTB normal = { SCALE f ( t * ) K CREF  if contact opening < LMTGAP                0                 if contact opening  LMTGAP MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaDa aaleaacaqGdbGaae4uaiaabsfacaqGcbaabaGaaeOBaiaab+gacaqG YbGaaeyBaiaabggacaqGSbaaaOGaeyypa0ZaaiqaaeaafaqabeGaba aabaGaae4uaiaaboeacaqGbbGaaeitaiaabweacqGHflY1caWGMbWa aeWaaeaacaWG0bWaaWbaaSqabeaacaGGQaaaaaGccaGLOaGaayzkaa GaeyyXICTaam4samaaBaaaleaacaqGdbGaaeOuaiaabweacaqGgbaa beaakiaabccacaqGPbGaaeOzaiaabccacaqGJbGaae4Baiaab6gaca qG0bGaaeyyaiaabogacaqG0bGaaeiiaiaab+gacaqGWbGaaeyzaiaa b6gacaqGPbGaaeOBaiaabEgacaqGGaGaaeipaiaabccacaqGmbGaae ytaiaabsfacaqGhbGaaeyqaiaabcfaaeaacaqGGaGaaeiiaiaabcca caqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiai aabccacaqGGaGaaeiiaiaabccacaqGWaGaaeiiaiaabccacaqGGaGa aeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccaca qGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGPbGaaeOzaiaa bccacaqGJbGaae4Baiaab6gacaqG0bGaaeyyaiaabogacaqG0bGaae iiaiaab+gacaqGWbGaaeyzaiaab6gacaqGPbGaaeOBaiaabEgacaqG GaGaeyyzImRaaeitaiaab2eacaqGubGaae4raiaabgeacaqGqbaaaa Gaay5Eaaaaaa@9720@
    Where,
    K CREF MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaBa aaleaacaqGdbGaaeOuaiaabweacaqGgbaabeaaaaa@3A1E@
    Reference stiffness for contact stabilization.
    Calculated as:
    • For a contact interface: 10-4 times the raw stiffness of the base elements of the contact.
    • For a CGAP/CGAPG element: 10-5 times the closed axial stiffness KA on PGAP.
    f ( t * ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaamiDamaaCaaaleqabaGaaiOkaaaaaOGaayjkaiaawMcaaaaa @3A48@
    Time-dependent scale factor.
    For time, t MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWG0baaaa@39D0@ in a subcase, t * MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWG0bWaaWbaaSqabeaacaGGQaaaaaaa@3AAB@ is calculated as:(2)
    t * = ( t t 0 ) / ( t 1 t 0 )
    Where,
    t 0 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWG0bWaaSbaaSqaaiaaicdaaeqaaaaa@3AB6@
    Time at the start of the subcase.
    t 1 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWG0bWaaSbaaSqaaiaaigdaaeqaaaaa@3AB7@
    Time at the end of the subcase.

    f ( t * ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaamiDamaaCaaaleqabaGaaiOkaaaaaOGaayjkaiaawMcaaaaa @3A48@ is calculated using S0 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaae4uaiaabc daaaa@377F@ and S1 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaae4uaiaabg daaaa@3780@ as f ( t * ) = S0 ( 1 t * ) + S1 ( t * ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm aabaGaamiDamaaCaaaleqabaGaaiOkaaaaaOGaayjkaiaawMcaaiab g2da9iaabofacaqGWaWaaeWaaeaacaaIXaGaeyOeI0IaamiDamaaCa aaleqabaGaaiOkaaaaaOGaayjkaiaawMcaaiabgUcaRiaabofacaqG XaWaaeWaaeaacaWG0bWaaWbaaSqabeaacaGGQaaaaaGccaGLOaGaay zkaaaaaa@47B9@ .

  3. When APSTB is YES, the contact tangent stabilization stiffness K CSTB tangent MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaDa aaleaacaqGdbGaae4uaiaabsfacaqGcbaabaGaaeiDaiaabggacaqG UbGaae4zaiaabwgacaqGUbGaaeiDaaaaaaa@40B1@ is calculated as:(3)
    K CSTB tangent =TFRAC K CSTB normal MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaDa aaleaacaqGdbGaae4uaiaabsfacaqGcbaabaGaaeiDaiaabggacaqG UbGaae4zaiaabwgacaqGUbGaaeiDaaaakiabg2da9iaabsfacaqGgb GaaeOuaiaabgeacaqGdbGaeyyXICTaam4samaaDaaaleaacaqGdbGa ae4uaiaabsfacaqGcbaabaGaaeOBaiaab+gacaqGYbGaaeyBaiaabg gacaqGSbaaaaaa@51DA@
  4. The defaults and priority information in conjunction with PARAM,EXPERTNL,CNTSTB for different contact types are:
    Table 1. Contact Stabililization. stabilization is not applicable to FREEZE or TIE Contact
    LGDISP or (LGDISP+SMDISP) g SMDISP
    N2S b/S2S CGAP/CGAPG N2S c

    (CGAPG-core)

    S2S CGAP/CGAPG
    PARAM,EXPERTNL,CNTSTB Damping d Artificial Spring e Artificial Spring e Damping d Artificial Spring e
    CNTSTB (Priority a)

    (Bulk card referenced by Subcase Entry)

    Damping

    (‘CNTINT’ or the first line of CNTSTB Bulk card)

    Damping f

    (‘GAPINT’)

    Damping

    (‘CNTINT’ or the first line of CNTSTB Bulk card)

    Damping

    (‘CNTINT’ or the first line of CNTSTB Bulk card)

    Damping f

    (‘GAPINT’)

    1. When both CNTSTB Subcase/Bulk Data pair and PARAM,EXPERTNL,CNTSTB are defined in a subcase, the CNTSTB Subcase/Bulk Data pair takes priority. For other subcases, the stabilization with the PARAM is effective.
    2. When there are LGDISP subcases in a deck file, N2S contact will be converted to Internally generated contact (different from CGAPG), and the stabilization on N2S contact will be conducted in this category.
    3. CGAPG-core N2S is generated, when N2S contact is defined and there is no LGDISP subcases defined in a deck file. The stabilization on N2S contact will be conducted in this category.
    4. In this case, the stabilization activated with the PARAM is consistent with the stabilization activated with default settings of the CNTSTB Bulk Data Entry.
    5. The artificial spring stiffness is determined by: (4)
      K a s = max { 0.01 K ( 10 6 t 10 6 ) , 0.0 } MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaBa aaleaacaWGHbGaam4CaaqabaGccqGH9aqpciGGTbGaaiyyaiaacIha daGadaqaaiaaicdacaGGUaGaaGimaiaaigdacaWGlbWaaeWaaeaaca aIXaGaaGimamaaCaaaleqabaGaeyOeI0IaaGOnaiaadshaaaGccqGH sislcaaIXaGaaGimamaaCaaaleqabaGaeyOeI0IaaGOnaaaaaOGaay jkaiaawMcaaiaacYcacaaIWaGaaiOlaiaaicdaaiaawUhacaGL9baa aaa@4F8E@
      Where,
      K a s MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4samaaBa aaleaacaWGHbGaam4Caaqabaaaaa@38D1@
      Artificial spring stiffness used to stabilize the gap elements.
      K MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4saaaa@36C7@
      Reference gap stiffness, generally it represents the stiffness of surrounding elements.
      t MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4saaaa@36C7@
      Global analysis time.
    6. The data defined in the first line of this card does not apply on CGAP/CGAPG elements. In order to apply damping stabilization on these elements, continuation lines with ‘GAPINT’ flag must be defined and referenced.
    7. SMDISP+LGDISP indicates models which contain both SMDISP subcases and LGDISP subcases in the same model.
  5. Contact stabilization introduces artificial energy that can delay the open-to-close and close-to-open transitions, and it should be used with caution.
  6. This card is represented as a load collector in HyperMesh.