MCOHE

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

Format


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MCOHE	`MID`	`MODEL`
	`COHE`	`CRTOD`	`MAXOD`	`BETA`	`EXP`	`VED`		`SFC`

Example 1


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MCOHE	2	1
	20.0	0.02	0.2					1.0e5

Example 2


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MCOHE	2	2
	10.0	0.03		0.5		1.0e-3		-1.0

Example 3


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MCOHE	2	3
	20.0	0.03			2.0	1.0e-4		SOFT

Definitions


Field	Contents	SI Unit Example
`MID`	Material identification number. No default (Integer > 0)
`MODEL`	Indicates the traction-separation relationship profile type. 1 Bilinear 2 Exponential 3 Linear-Exponential No default (Integer)
`COHE`	The energy per area that can be absorbed by the cohesive elements. It is the area under the traction-separation curve. No default (Real > 0.0)	$[\frac{N}{m}]$ or $[\frac{J}{m^{2}}]$
`CRTOD`	Critical opening distance. No default (Real ≥ 0.0)	$[m]$
`MAXOD`	Maximum opening displacement (bilinear model only). No default (Real > 0.0)	$[m]$
`BETA`	Coefficient on the shear opening for mode mix based on displacement. Default = 1.0 (Real ≥ 0.0)
`EXP`	Exponential decay factor (linear-exponential model only). No default (Real > 0.0)
`VED`	Viscous energy dissipation factor. Default = 0.0. (Real > 0.0)
`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

Comments

The material identification number must be unique for all MAT1, MAT2, MAT3, MAT8, MAT9, MGASK, MCOHE, and MCOHED entries.
In some cases, snap-back phenomena could appear in numerical models with cohesive elements. VED can be used to stabilize the solution.
For additional information, refer to Cohesive Zone Modeling in the User Guide.