/MAT/LAW5 (JWL)

Block Format Keyword

/MAT/LAW5 - Jones Wilkins-Lee Material

Description

This law describes the Jones-Wilkins-Lee EOS for detonation products of high explosives.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/MAT/LAW5/mat_ID or /MAT/JWL/mat_ID
mat_title

A		B		R1		R2
D		PCJ		E0		Eadd		IBFRAC

Insert if Eadd > 0

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
Tstart		Tstop

Field	Contents	SI Unit Example
mat_ID	Material identifier (Integer, maximum 10 digits)
mat_title	Material title (Character, maximum 100 characters)
	Initial density (Real)
	Reference density used in E.O.S (equation of state) Default = (Real)
A	A parameter of equation of state (Real)
B	B parameter of equation of state (Real)
R1	R1 parameter of equation of state (Real)
R2	R2 parameter of equation of state (Real)
	parameter of equation of state (Real)
D	Detonation velocity (Real)
PCJ	Chapman Jouguet pressure (Real)
E0	Detonation energy per unit volume (Real)
Eadd	Additional energy per unit volume (Real)
IBFRAC	Burn fraction calculation flag (Comment 3) (Integer) = 0: Volumetric Compression + Burning Time = 1: Volumetric Compression only = 2: Burning Time only
Tstart	Start time for additional energy (Real)
Tstop	Stop time for additional energy (Real)

(TNT)

#RADIOSS STARTER

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

#- 2. MATERIALS:

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/MAT/JWL/2

TNT - data from example 46

# RHO_I RHO_0

1.63 0

# A B R1 R2 OMEGA

3.7121 .0323 4.15 .95 .3

# D P_CJ E0 Eadd I_BFRAC

.693 .21 .07 0 0

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

#ENDDATA

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Where, V is the relative volume:

E is the internal energy per unit initial volume:

and

Where, is the adiabatic constant.

The Jones Wilkins Lee Material Law (Law 5) may be used as a boundary for Hydrodynamic Viscous Fluid Material (/MAT/LAW6) provided the flow direction is from Law 5 to Law 6 (simulation of an explosion), and the gas properties (

) are similar. Nevertheless this method is not the most accurate one and multi-material law (/MAT/LAW51) is recommended instead.

3.	Detonation Velocity (D) and Chapman Jouget Pressure (PCJ) are used in the burn fraction calculation (). It controls the release of detonation energy and corresponds to a factor which multiplies JWL pressure.

For a given time:

A lighting time, Tdet, is computed by the Starter from the detonation velocity. During the simulation the burn fraction is computed as follows:

Where,

It can take several cycles for the burn fraction to reach its maximum value of 1.00.

Burn fraction calculation can be changed defining IBFRAC flag:

IBFRAC = 1:

IBFRAC = 2:

4.	Time histories for detonation time and burn fraction are available through /TH/BRIC with keyword BFRAC. You can output a function, f, whose first value is detonation time (with opposite sign) and positive values corresponds to the burn fraction evolution.

5.	Detonation times can be written in the Starter listing file for each JWL element. The printout flag (Ipri) must be greater than or equal to 3 (/IOFLAG).

6.	If no detonation card is linked to the material, then instantaneous detonation will be assumed.

/MAT/LAW5 (JWL)

/MAT/LAW5 (JWL)

/MAT/LAW5 (JWL)

Format

See Also: