Shock EOS Bilinear

This is an extension of the Shock EOS Linear property. At high shock strengths nonlinearity in the shock velocity - particle velocity relationship is apparent, particularly for non-metallic materials. To account for this nonlinearity, the input calls for the definition of two linear fits to the shock velocity - particle velocity relationship; one at low shock compressions defined by Up > VB and one at high shock compressions defined by Up < VE.

The region between VE and VB is covered by a smooth interpolation between the two linear relationships as shown below.

Figure 53:  Fit to Shock Velocity-Particle Velocity Relationship

Fit to Shock Velocity-Particle Velocity Relationship

In the input you are prompted for values of the parameters c1, c2, s1, s2, VE/Vo, VB/Vo, Γo and ρo. Then


Note:  This equation of state can only be applied to solid bodies.

The Poisson's ratio is assumed to be zero when calculating effective strain.

A specific heat capacity should be defined with this property to allow the calculation of temperature.


Table 127:  Input Data

NameSymbolUnitsNotes
Gruneisen coefficientΓNone 
Parameter C1C1Velocity 
Parameter S1S1None 
Parameter C2C2Velocity 
Parameter S2S2None 
Relative Volume VB/V0VB/V0None 
Relative Volume VE/V0VE/V0None 

This equation of state can only be used with solid elements.

Custom results variables available for this model:

NameDescriptionSolidsShellsBeams
PRESSUREPressureYesNoNo
DENSITYDensityYesNoNo
COMPRESSIONCompressionYesNoNo
VISC_PRESSUREViscous PressureYesNoNo
INT_ENERGYInternal EnergyYesNoNo
TEMPERATURETemperatureYesNoNo

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