MATX25

Bulk Data Entry

MATX25 – Material Property Extension for Tsai-Wu and CRASURVT Materials for Geometric Nonlinear Analysis

Description

Defines an elasto-plastic orthotropic material with Tsai-Wu and CRASURVT yield criteria for composite shell materials.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MATX25	MID	EPSF1	EPSF2	EPST1	EPSM1	EPST2	EPSM2	DTENDS
	WPMAX	WPREF	IOFF	GAMINI	GAMMAX	DMAX	RATIO
	FSMOOTH	FCUT	IFORM

Continuation line for IFORM = TSAI

B	N	FMAX
SY1T	SY2T	SY1C	SY2C	ALFA
SY12C	SY12T	C12	EPSR0	ICC

Continuation line for IFORM = CRAS

C	EPSR0	ALFA	ICCG
SY1T	B1T	N1T	SMAX1T	C1T
EPS1T1	EPS2T1	SRST1	WMPT1
SY2T	B2T	N2T	SMAX2T	C2T
EPS1T2	EPS2T2	SRST2	WMPT2
SY1C	B1C	N1C	SMAX1C	C1C
EPS1C1	EPS2C1	SRSC1	WMPC1
SY2C	B2C	N2C	SMAX2C	C2C
EPS1C2	EPS2C2	SRSC2	WMPC2
SY12T	B12T	N12T	SMAX12T	C12T
EPS1T12	EPS2T12	SRST12	WMPT12

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MAT8	102	70000	70000	0.3	26923.1	26923.1	26923.1
MATX25	102			0.15	0.2			0.95
			2

	0.2	1.0	2.0
	1E10	1E10	1E10	1E10
	1E10	1E10

Field	Contents
MID	Material ID of the associated MAT8. See comment 1. No default (Integer > 0)
EPSF1	Total tensile failure in direction 1. Default = 1E30 (Real)
EPSF2	Total tensile failure in direction 2. Default = 1E30 (Real)
EPST1	Tensile failure strain in direction 1. (Real)
EPSM1	Maximum strain in direction 1. (Real)
EPST2	Tensile failure strain in direction 2. (Real)
EPSM2	Maximum strain in direction 2. (Real)
DTENDS	Maximum damage of composite tensile strength. Default = 0.999 (Real < 1.0)
WPMAX	Maximum plastic work. Default = 1E30 (Real)
WPREF	Reference plastic work. Default = 1.0 (Real)
IOFF	Total element failure criteria. Default = 0 (Integer) = 0: shell is deleted if Wp* > Wpmax for 1 layer = 1: shell is deleted if Wp > Wpmax for all layers = 2: if for each layer, Wp > Wpmax or tensile failure in direction 1(t1) = 3: if for each layer, Wp > Wpmax or tensile failure in direction 2(t2) = 4: if for each layer, Wp > Wpmax or tensile failure in directions 1(t1) and 2(t2) = 5: if for all layers: Wp > Wpmax or tensile failure in direction 1(t1) or if for all layers: Wp > Wpmax or tensile failure in direction 2(t2) = 6: if for each layer, Wp > Wp*max or tensile failure in direction 1(t1) or 2(t2)
GAMINI	Delamination shear strain. See comment 11. Default = 1E30 (Real)
GAMMAX	Maximum shear strain. Default = 1.1E30 (Real)
DMAX	Maximum damage. Default = 1.0 (Real)
RATIO	Ratio parameter control to delete shell elements Default = 1.0 (Real) < 0.0: the element will be deleted if all of the layers but one fail (the number of layers that did not fail is equal to 1). > 0.0: the element will be deleted if:
FSMOOTH	Strain rate smoothing flag. Default = OFF (ON or OFF)
FCUT	Cutoff frequency for strain rate filtering. Default = 1E30 (Real)
IFORM	Formulation flag. Default = TSAI (TSAI or CRAS)
IFORM = TSAI
B	Hardening parameter. (Real)
N	Hardening exponent. Default = 1.0 (Real)
FMAX	Maximum value of yield function. Default = 1E30 (Real)
SY1T	Tension in direction 1. (Real > 0)
SY2T	Tension in direction 2. (Real > 0)
SY1C	Compression yield stress in direction 1. (Real > 0)
SY2C	Compression yield stress in direction 2. (Real > 0)
ALFA	F12 reduction factor. Default = 1.0 (Real)
SY12C	Compression yield stress in direction 12. (Real > 0)
SY12T	Tension yield stress in direction 12. (Real > 0)
C12	Strain rate coefficient. (Real) = 0.0: no strain rate dependency.
EPSR0	Reference strain rate. (Real)
ICC	Flag for yield stress in shear and strain rate. See comment 9. (Integer) = 0: Default set to 1 = 1: Strain rate effect on FMAX no effect on WPMAX = 2: No strain rate effect on FMAX and WPMAX = 3: Strain rate effect on FMAX and WPMAX = 4: No strain rate effect on FMAX effect on WPMAX
IFORM = CRAS
C	Global strain rate coefficient for plastic work criteria. (Real)
EPSR0	Reference strain rate. (Real)
ALFA	F12 reduction factor. Default= 1.0 (Real)
ICCG	Global composite plasticity parameters flag for strain rate computation: (See comment 9). = 1: Strain rate effect on SMAX1T, SMAX2T, SMAX1C, SMAX2C, SMAX12T; no strain rate effect on WPMAX. = 2: No strain rate effect on SMAX1T, SMAX2T, SMAX1C, SMAX2C, SMAX12T; no strain rate effect on WPMAX. = 3: Strain rate effect on SMAX1T, SMAX2T, SMAX1C, SMAX2C, SMAX12T and strain rate effect on WPMAX. = 4: No strain rate effect on SMAX1T, SMAX2T, SMAX1C, SMAX2C, SMAX12T and strain rate effect on WPMAX. Default = 1 (Integer)
SY1T	Tension yield stress in direction 1. (Real > 0)
B1T	Hardening parameter in direction 1. (Real)
N1T	Hardening exponent in direction 1. Default = 1.0 (Real)
SMAX1T	Maximum stress in direction 1. Default = 1E30 (Real)
C1T	Strain rate coefficient in direction 1. 0: no strain rate dependency. Default = C (Real)
EPS1T1	Initial softening strain in direction 1. Default = 1E30 (Real)
EPS2T1	Maximum softening strain in direction 1. Default = 1.2 * EPS1T1 (Real)
SRST1	Residual stress in direction 1. Default = 10E-3*SY1T (Real)
WMPT1	Maximum plastic work in tension direction 1. Default = 1E30 (Real)
SY2T	Tension yield stress in direction 2. (Real > 0)
B2T	Hardening parameter in direction 2. Default = B1T (Real)
N2T	Hardening exponent in direction 2. Default = N1T (Real)
SMAX2T	Maximum stress in direction 2. Default = 1E30 (Real)
C2T	Strain rate coefficient in direction 2. 0: no strain rate dependency Default = C (Real)
EPS1T2	Initial softening strain in direction 2. Default = 1E30 (Real)
EPS2T2	Maximum softening strain in direction 2. Default = 1.2*EPS1T1 (Real)
SRST2	Residual stress in direction 2. Default = 10E-3 * SY2T (Real)
WMPT2	Maximum plastic work in tension direction 2. Default = 1E30 (Real)
SY1C	Compression yield stress in direction 1. (Real > 0)
B1C	Hardening parameter in direction 1. Default = B2T (Real)
N1C	Hardening exponent in direction 1. Default = N2T (Real)
SMAX1C	Maximum stress in direction 1. Default = 1E30 (Real)
C1C	Strain rate coefficient in direction 1. = 0.0: no strain rate dependency. Default = C (Real)
EPS1C1	Initial softening strain in direction 1. Default = 1E30 (Real)
ESP2C1	Maximum softening strain in direction 1. Default = 1.2*EPS1C1 (Real)
SRSC1	Residual stress in direction 1. Default = 10E-3*S1YC (Real)
WMPC1	Maximum plastic work in compression direction 1. Default = 1E30 (Real)
SY2C	Compression yield stress in direction 2. (Real > 0)
B2C	Hardening parameter in direction 2. Default = B1C (Real)
N2C	Hardening exponent in direction 2 Default = N1C (Real)
SMAX2C	Maximum stress in direction 2. Default = 1E30 (Real)
C2C	Strain rate coefficient in direction 2. = 0.0: no strain rate dependency. Default = C (Real)
EPS1C2	Initial softening strain in direction 2. Default = 1E30 (Real)
EPS2C2	Maximum softening strain in direction 2. Default = 1.2*EPS1C2 (Real)
SRSC2	Residual stress in direction 2. Default = 10E-3*S2YC (Real)
WMPC2	Maximum plastic work in compression direction 2. Default = 1E30 (Real)
SY12T	Tension yield stress in direction 12. (Real > 0)
B12T	Hardening parameter in direction 12. Default = B2C (Real)
N12T	Hardening exponent in direction 12. Default = 1.0 (Real)
SMAX12T	Maximum stress in direction 12. Default = 1E30 (Real)
C12T	Strain rate coefficient in direction 12. = 0.0: no strain rate dependency. Default = C (Real)
EPS1T12	Initial softening strain in direction 12. Default = 1E30 (Real)
EPS2T12	Maximum softening strain in direction 12. Default = 1.2*EPS1T12 (Real)
SRST12	Residual stress in direction 12. Default = 10E-3*SY12T (Real)
WMPT12	Maximum plastic work in shear. Default = 1E30 (Real)

Comments

1.	The material identification number must be that of an existing MAT8 bulk data entry. Only one MATXi material extension can be associated with a particular MAT8.

2.	MATX25 is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS = EXPDYN. It is ignored for all other subcases.

3.	Tsai-Wu formula (IFORM=TSAI) is not available with QEPH (ISHELL=24 on PCOMPX) shell elements, it is only available with Q4 (ISHELL=1, 2, 3, 4 on PCOMPX) and QBAT(ISHELL=12 on PCOMPX) shell elements.

4.	The Lamina yield surface for Tsai-Wu criteria (IFORM=TSAI) is:

matx25_eq1

Where,

Wp is the plastic work

is the reference plastic work

matx25_eq4 is the yield envelope evolution:

Where,

b is the hardening parameter for plastic work

n is the hardening exponent

matx25_eq5

5.	The CRASURV model is an improved version of the former law based on the standard Tsai-Wu criteria. The main changes concern the expression of the yield surface before plastification and during work hardening. First, in a CRASURV model, the coefficient F44 depends only on one input parameter:

matx25_eq6

Another modification concerns the parameters Fij which are expressed now in function of plastic work and plastic work rate, as shown below:

matx25_eq7

6.	If the total tensile failure value EPSF1 is reached in the direction 1 and respectively ε EPSF2 in the direction 2, the stresses tensor in the layer is permanently reset to 0.

7.	If a shell has several layers with one material per layer (different materials, different IOFF), the IOFF used is the one that is associated to the shell in the shell element definition.

8.	Both Wp* and Wp*max are defined as follows:

matx25_eq8

9.	The plastic work criteria is:

matx25_eq8a

When ICC=2, 3, or 4 for Tsai-Wu formula, when ICCG=3 or 4 for CRASURV formula.

10.	Delamination is a global model:

matx25_eq9

with applies to the all shell and not independently per each layer.

11.	Thereby, the coefficients GAMINI, GAMMAX, and DMAX considered, are the coefficients which are defined in the global material associated to the shell equivalent out-of-plane shear strain.

12.	The IOFF and RATIO field values are utilized only if they are defined in the material assigned to a part, these fields are not considered if they are only defined in material used for a layer in the property entry. This option is not available for solid elements.

13.	This card is represented as extension to a MAT8 material in HyperMesh.