MCOHED

Bulk Data Entry Defines the material properties for damage-based cohesive material models.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MCOHED MID KI KII KIII SFC VED   MXDMG  
  DMGINIID DMGEVOID              

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MCOHED 2 9000. 3000. 3000. -1.0 1.0e-3   0.99  
  20 23              

Definitions

Field Contents SI Unit Example
MID Material identification number.

No default (Integer > 0)

  
KX, KY, KZ Elasticity modulus corresponding to Mode I, II and III deformation, when the card is used in cohesive elements.

Penalty stiffness corresponding to Mode I, II and III deformation, when the card is used in cohesive contacts. 2

No default (Real)

 N m 2 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca WGobaabaGaamyBamaaCaaaleqabaGaaGOmaaaaaaaaaa@38B4@ for cohesive elements

N m 3 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca WGobaabaGaamyBamaaCaaaleqabaGaaGOmaaaaaaaaaa@38B4@ for cohesive contacts
SFC Stiffening factor in compression.
Positive value (Real > 0.0)
Directly prescribed stiffness
Negative value (Real < 0.0)
Defines a stiffness scaling factor. The stiffness scaling factor is equal to |Real< 0.0|. The scaling is applied to the initial stiffness in separation condition.
SOFT
Takes the maximum diagonal value in the global stiffness of the numerical model multiplied by 1.0E2 as the compression stiffness.
HARD
Takes the maximum diagonal value in the global stiffness of the numerical model multiplied by 1.0E6 as the compression stiffness.
AUTO
Takes the maximum diagonal value in the global stiffness of the numerical model multiplied by 1.0E4 as the compression stiffness.

Default = 1.0

  
VED Factor for viscous energy dissipation. 3

Default = 0.0 (Real > 0.0)

  
MXDMG Maximum damage index, above which the cohesive element is excluded from analysis.

Default = 1.0 (Real ≥ 0.0)

  
DMGINIID Damage initiation card ID.

No default (Integer > 0)

  
DMGEVOID Damage evolution card ID.

No default (Integer > 0)

  

Comments

  1. The material identification number should be unique for all MAT1, MAT2, MAT3, MAT8, MAT9, MGASK, MCOHE, MCOHED entries.
  2. In cohesive contacts, it is recommended to use KII = KIII.
  3. In some cases, snap-back phenomena could appear in numerical models with cohesive elements. VED can be used to stabilize the solution.
  4. For additional information, refer to Cohesive Zone Modeling in the User Guide.