Mechanical Continuum Material

The mechanical continuum material is divided in the following materials:

Elastic

The elastic material requires the following properties:

Property	Description	Type	Def. Unit	required
E	Elasticity modulus	Scalar	kPa	Yes
nu	Poisson ratio	Scalar	–	Yes

Example:

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E',   description = 'Elasticity modulus',  unit = 'kPa'},
    {id = 'nu',  description = 'Poisson ratio',  unit = ''},
  },
  values = {
    {E = 2e+07, nu = 0.3},
  }
}

Von Mises

The von Mises material requires the following properties:

Property	Description	Type	Def. Unit	required
E	Elasticity modulus	Scalar	kPa	Yes
nu	Poisson ratio	Scalar	–	Yes
Sy	Yield stress	Scalar	kPa	Yes
K	Plastic Modulus	Scalar	–	No

Example:

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E',   description = 'Elasticity modulus',  unit = 'kPa'},
    {id = 'nu',  description = 'Poisson ratio',  unit = ''},
    {id ='Sy', description = 'yield stress', unit =     'kPa'},
    {id = 'K', description = 'plastic modulus', unit = ''},
  },
  values = {
    {E = 1e+07, nu = 0.24, Sy = 16000, K = 10},
  }
}

Druker-Prager

The Drucker-Prager material requires the following properties:

Property	Description	Type	Def. Unit	required
E	Elasticity modulus	Scalar	kPa	Yes
nu	Poisson ratio	Scalar	–	Yes
Coh	Cohesion	Scalar	kPa	Yes
Phi	Angle of internal friction	Scalar	(*)	Yes
Psi	Angle of dilation	Scalar	(*)	Yes

(*) The angle of internal friction and dilation must be defined in degree.

Example:

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E',   description = 'Elasticity modulus',  unit = 'kPa'},
    {id = 'nu',  description = 'Poisson ratio',  unit = ''},
    {id = 'Coh', description = 'Cohesion', unit =       'kPa'},
    {id = 'Phi', description = 'Angle of internal friction', unit = ''},
    {id = 'Psi', description = 'Angle of dilation', unit = ''},
  },
  values = {
    {E = 1e+07, nu = 0.24, Coh = 100, Phi = 20, Psi = 20},
  }
}

Modified Mohr Coulomb

The Modified Mohr Coulomb is based on the hyperbolic Mohr Coulomb model proposed by Abbo. This material requires the following properties:

Property	Description	Type	Def. Unit	required
E	Elasticity modulus	Scalar	kPa	Yes
nu	Poisson ratio	Scalar	–	Yes
Coh	Cohesion	Scalar	kPa	Yes
Phi	Angle of internal friction	Scalar	(*)	Yes
Psi	Angle of dilation	Scalar	(*)	Yes

(*) The angle of internal friction and dilation must be defined in degree.

Example:

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E',   description = 'Elasticity modulus',  unit = 'kPa'},
    {id = 'nu',  description = 'Poisson ratio',  unit = ''},
    {id = 'Coh', description = 'Cohesion', unit =       'kPa'},
    {id = 'Phi', description = 'Angle of internal friction', unit = ''},
    {id = 'Psi', description = 'Angle of dilation', unit = ''},
  },
  values = {
    {E = 1e+07, nu = 0.24, Coh = 100, Phi = 25, Psi = 25},
  }
}

Fractured Rock

The Fractured rock material considers the equivalent behavior of an intact rock and sets of discontinuities. This material requires the following properties:

Property	Description	Type	Def. Unit	required
E	Elasticity modulus	Scalar	kPa	Yes
nu	Poisson ratio	Scalar	–	Yes
Knf	Normal elastic stiffness of fracture	Scalar /vector	kPa/m	Yes
Ksf	shear elastic stiffness of fracture	Scalar /vector	kPa/m	Yes
Sfr	Fracture spacing	Scalar /vector	m	Yes
Dip	Angle of Dip	Scalar /vector	(*)	Yes
Strike	Angle of Strike	Scalar /vector	(*)	Yes

(*) The Dip and Strike angle must be defined in degree.

Example: An intact rock with two sets of fractures

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E',   description = 'Elasticity modulus',  unit = 'kPa'},
    {id = 'nu',  description = 'Poisson ratio',  unit = ''},
    {id = 'Knf', description = 'Normal elastic stiffness of fracture', units = 'kPa/m', dim = '2'},
    {id = 'Ksf', description = 'shear elastic stiffness of fracture', units = 'kPa/m', dim = '2'},
    {id = 'Sfr', description = 'Fracture spacing', units = 'm', dim = '2'},
    {id = 'Dip', description = 'Angle of Dip', units = '', dim = '2'},
    {id = 'Strike', description = 'Angle of Strike', units = '', dim = '2'},
  },
  values = {
   {E =  66.0e+06, nu = 0.25, Knf = {13.9e+06, 27.0e+06 }, Ksf = {6.95e+06, 13.0e+06}, Sfr = {0.1, 0.25}, Dip = {30, 20}, Strike = {0, 90}},
  }
}

Isotropic Damage Model

See isotropicDamage

Solidifying Kelvin Chain

The Solidifying Kelvin Chain material considers the Solidication Theory proposed by Bazant applied in Kelvin chains to represent the basic creep of concrete.

This material requires the following properties:

Property	Description	Type	Def. Unit	Required
E0	Elastic modulus of outer spring	Scalar	kPa	Yes
nu	Poisson`s ratio	Scalar	–	Yes
Ei	Elastic moduli of Kelvin chain	Scalar /vector	kPa	Yes
tau	Retardation times of Kelvin chain	Scalar /vector	day	Yes
alpha (*)	Aging alpha factor	Scalar	–	Yes

(*) If alpha is declared equal to zero, the material will not have aging.

Example: Solidifying Kelvin chain with three elements.

-- Number of Kelvin elements
local kelDim = 3  

PropertySet
{
  id          = 'MatProp',
  typeName    = 'GemaPropertySet',
  description = 'Material properties',
  properties  = {
    {id = 'E0',        description = 'Elastic modulus of outer spring',                 unit = 'kPa'                     },
    {id = 'nu',        description = 'Poisson ratio',                                   unit = ''                        },
    {id = 'Ei',        description = 'Elastic modulus of kelvin chain',   dim = kelDim, unit = 'MPa'                     },
    {id = 'tau',       description = 'Retardation times of kelvin chain', dim = kelDim, unit = 'day'                     },
    {id = 'alpha',     description = 'Aging alpha factor',                              unit = ''                        },
    {id = 'materialM', description = 'Mechanical material type', constMap = constants.MechanicalFemPhysics.materialModels},
  },
  values = {
    {E0 = 43.2e+06, nu = 0.2, Ei = {76.9e+06, 225.5e+06, 65.2e+06}, tau = {1, 10, 100}, alpha = 0.76, materialM = 'solidifyingKelvinChain'},
  } 
}

See more about Solidifying Kelvin chain.

Returns to Mechanical continuum material.

GeMA project main page