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 # RAPhysics

 Last update: 23.02.2026 

<a id="generated.RAPhysics"></a>

### *class* RAPhysics

Rocky PrePost Scripting wrapper to manipulate physics properties.

This class represents the “Physics” item on the project data tree. To get the [`RAPhysics`](#generated.RAPhysics)from a [`RAStudy`](RAStudy.md#generated.RAStudy), use:

```python
physics = study.GetPhysics()

```

**Methods:**

NameDescription[`GetAdhesionModel`](#generated.RAPhysics.GetAdhesionModel)()Get "Adhesion Model" as a string.[`GetClosePackingVolumeFraction`](#generated.RAPhysics.GetClosePackingVolumeFraction)()Get the value of "Close Packing Volume Fraction".[`GetEnableCoarseGrainModeling`](#generated.RAPhysics.GetEnableCoarseGrainModeling)()Get the value of "Enable Coarse Grain Modeling".[`GetEnableThermalModel`](#generated.RAPhysics.GetEnableThermalModel)()Get the value of "Enable Thermal Model".[`GetExponentLimit`](#generated.RAPhysics.GetExponentLimit)()Get the value of "Exponent Limit".[`GetGravityStartTime`](#generated.RAPhysics.GetGravityStartTime)(\[unit\])Get the value of "Gravity Start Time".[`GetGravityStopTime`](#generated.RAPhysics.GetGravityStopTime)(\[unit\])Get the value of "Gravity Stop Time".[`GetGravityXDirection`](#generated.RAPhysics.GetGravityXDirection)(\[unit\])Get the value of "Gravity X Direction".[`GetGravityYDirection`](#generated.RAPhysics.GetGravityYDirection)(\[unit\])Get the value of "Gravity Y Direction".[`GetGravityZDirection`](#generated.RAPhysics.GetGravityZDirection)(\[unit\])Get the value of "Gravity Z Direction".[`GetImpactEnergyModel`](#generated.RAPhysics.GetImpactEnergyModel)()Get "Impact Energy Model" as a string.[`GetNormalForceModel`](#generated.RAPhysics.GetNormalForceModel)()Get "Normal Force Model" as a string.[`GetNumericalSofteningFactor`](#generated.RAPhysics.GetNumericalSofteningFactor)()Get the value of "Numerical Softening Factor".[`GetRestitutionModel`](#generated.RAPhysics.GetRestitutionModel)()Get "Restitution Model" as a string.[`GetRollingResistanceModel`](#generated.RAPhysics.GetRollingResistanceModel)()Get "Rolling Resistance Model" as a string.[`GetSearchDistanceMultiplier`](#generated.RAPhysics.GetSearchDistanceMultiplier)()Get the value of "Search Distance Multiplier".[`GetSphThermalTransferModel`](#generated.RAPhysics.GetSphThermalTransferModel)()Get "Sph Thermal Transfer Model" as a string.[`GetTangentialForceModel`](#generated.RAPhysics.GetTangentialForceModel)()Get "Tangential Force Model" as a string.[`GetThermalCorrectionModel`](#generated.RAPhysics.GetThermalCorrectionModel)()Get "Thermal Correction Model" as a string.[`GetUpdateDistanceMultiplier`](#generated.RAPhysics.GetUpdateDistanceMultiplier)()Get the value of "Update Distance Multiplier".[`GetUseRadlEtAl`](#generated.RAPhysics.GetUseRadlEtAl)()Get the value of "Use Radl Et Al".[`GetValidAdhesionModelValues`](#generated.RAPhysics.GetValidAdhesionModelValues)()Get a list of all possible values for "Adhesion Model".[`GetValidImpactEnergyModelValues`](#generated.RAPhysics.GetValidImpactEnergyModelValues)()Get a list of all possible values for "Impact Energy Model".[`GetValidNormalForceModelValues`](#generated.RAPhysics.GetValidNormalForceModelValues)()Get a list of all possible values for "Normal Force Model".[`GetValidRestitutionModelValues`](#generated.RAPhysics.GetValidRestitutionModelValues)()Get a list of all possible values for "Restitution Model".[`GetValidRollingResistanceModelValues`](#generated.RAPhysics.GetValidRollingResistanceModelValues)()Get a list of all possible values for "Rolling Resistance Model".[`GetValidSphThermalTransferModelValues`](#generated.RAPhysics.GetValidSphThermalTransferModelValues)()Get a list of all possible values for "Sph Thermal Transfer Model".[`GetValidTangentialForceModelValues`](#generated.RAPhysics.GetValidTangentialForceModelValues)()Get a list of all possible values for "Tangential Force Model".[`GetValidThermalCorrectionModelValues`](#generated.RAPhysics.GetValidThermalCorrectionModelValues)()Get a list of all possible values for "Thermal Correction Model".[`GetVolumeFractionLimit`](#generated.RAPhysics.GetVolumeFractionLimit)()Get the value of "Volume Fraction Limit".[`SetAdhesionModel`](#generated.RAPhysics.SetAdhesionModel)(value)Set the value of "Adhesion Model".[`SetClosePackingVolumeFraction`](#generated.RAPhysics.SetClosePackingVolumeFraction)(value)Set the value of "Close Packing Volume Fraction".[`SetEnableCoarseGrainModeling`](#generated.RAPhysics.SetEnableCoarseGrainModeling)(value)Set the value of "Enable Coarse Grain Modeling".[`SetEnableThermalModel`](#generated.RAPhysics.SetEnableThermalModel)(value)Set the value of "Enable Thermal Model".[`SetExponentLimit`](#generated.RAPhysics.SetExponentLimit)(value)Set the value of "Exponent Limit".[`SetGravityStartTime`](#generated.RAPhysics.SetGravityStartTime)(value\[, unit\])Set the value of "Gravity Start Time".[`SetGravityStopTime`](#generated.RAPhysics.SetGravityStopTime)(value\[, unit\])Set the value of "Gravity Stop Time".[`SetGravityXDirection`](#generated.RAPhysics.SetGravityXDirection)(value\[, unit\])Set the value of "Gravity X Direction".[`SetGravityYDirection`](#generated.RAPhysics.SetGravityYDirection)(value\[, unit\])Set the value of "Gravity Y Direction".[`SetGravityZDirection`](#generated.RAPhysics.SetGravityZDirection)(value\[, unit\])Set the value of "Gravity Z Direction".[`SetImpactEnergyModel`](#generated.RAPhysics.SetImpactEnergyModel)(value)Set the value of "Impact Energy Model".[`SetNormalForceModel`](#generated.RAPhysics.SetNormalForceModel)(value)Set the value of "Normal Force Model".[`SetNumericalSofteningFactor`](#generated.RAPhysics.SetNumericalSofteningFactor)(value)Set the value of "Numerical Softening Factor".[`SetRestitutionModel`](#generated.RAPhysics.SetRestitutionModel)(value)Set the value of "Restitution Model".[`SetRollingResistanceModel`](#generated.RAPhysics.SetRollingResistanceModel)(value)Set the value of "Rolling Resistance Model".[`SetSearchDistanceMultiplier`](#generated.RAPhysics.SetSearchDistanceMultiplier)(value)Set the value of "Search Distance Multiplier".[`SetSphThermalTransferModel`](#generated.RAPhysics.SetSphThermalTransferModel)(value)Set the value of "Sph Thermal Transfer Model".[`SetTangentialForceModel`](#generated.RAPhysics.SetTangentialForceModel)(value)Set the value of "Tangential Force Model".[`SetThermalCorrectionModel`](#generated.RAPhysics.SetThermalCorrectionModel)(value)Set the value of "Thermal Correction Model".[`SetUpdateDistanceMultiplier`](#generated.RAPhysics.SetUpdateDistanceMultiplier)(value)Set the value of "Update Distance Multiplier".[`SetUseRadlEtAl`](#generated.RAPhysics.SetUseRadlEtAl)(value)Set the value of "Use Radl Et Al".[`SetVolumeFractionLimit`](#generated.RAPhysics.SetVolumeFractionLimit)(value)Set the value of "Volume Fraction Limit".<a id="generated.RAPhysics.GetAdhesionModel"></a>

#### GetAdhesionModel()

Get “Adhesion Model” as a string.

- **Returns:**The returned value will be one of \[‘none’, ‘constant’, ‘linear’, ‘JKR’, ‘custom’\].

<a id="generated.RAPhysics.GetClosePackingVolumeFraction"></a>

#### GetClosePackingVolumeFraction()

Get the value of “Close Packing Volume Fraction”.

<a id="generated.RAPhysics.GetEnableCoarseGrainModeling"></a>

#### GetEnableCoarseGrainModeling()

Get the value of “Enable Coarse Grain Modeling”.

<a id="generated.RAPhysics.GetEnableThermalModel"></a>

#### GetEnableThermalModel()

Get the value of “Enable Thermal Model”.

<a id="generated.RAPhysics.GetExponentLimit"></a>

#### GetExponentLimit()

Get the value of “Exponent Limit”.

<a id="generated.RAPhysics.GetGravityStartTime"></a>

#### GetGravityStartTime(unit: str | None = None)

Get the value of “Gravity Start Time”.

- **Parameters:****unit** – The unit for the returned value. If no unit is provided, the returned value will be in “s”.

<a id="generated.RAPhysics.GetGravityStopTime"></a>

#### GetGravityStopTime(unit: str | None = None)

Get the value of “Gravity Stop Time”.

- **Parameters:****unit** – The unit for the returned value. If no unit is provided, the returned value will be in “s”.

<a id="generated.RAPhysics.GetGravityXDirection"></a>

#### GetGravityXDirection(unit: str | None = None)

Get the value of “Gravity X Direction”.

- **Parameters:****unit** – The unit for the returned value. If no unit is provided, the returned value will be in “m/s2”.

<a id="generated.RAPhysics.GetGravityYDirection"></a>

#### GetGravityYDirection(unit: str | None = None)

Get the value of “Gravity Y Direction”.

- **Parameters:****unit** – The unit for the returned value. If no unit is provided, the returned value will be in “m/s2”.

<a id="generated.RAPhysics.GetGravityZDirection"></a>

#### GetGravityZDirection(unit: str | None = None)

Get the value of “Gravity Z Direction”.

- **Parameters:****unit** – The unit for the returned value. If no unit is provided, the returned value will be in “m/s2”.

<a id="generated.RAPhysics.GetImpactEnergyModel"></a>

#### GetImpactEnergyModel()

Get “Impact Energy Model” as a string.

- **Returns:**The returned value will be one of \[‘default’, ‘custom’\].

<a id="generated.RAPhysics.GetNormalForceModel"></a>

#### GetNormalForceModel()

Get “Normal Force Model” as a string.

- **Returns:**The returned value will be one of \[‘linear\_hysteresis’, ‘linear\_elastic\_viscous’, ‘damped\_hertzian’, ‘custom’\].

<a id="generated.RAPhysics.GetNumericalSofteningFactor"></a>

#### GetNumericalSofteningFactor()

Get the value of “Numerical Softening Factor”.

<a id="generated.RAPhysics.GetRestitutionModel"></a>

#### GetRestitutionModel()

Get “Restitution Model” as a string.

- **Returns:**The returned value will be one of \[‘constant’, ‘velocity\_dependent’\].

<a id="generated.RAPhysics.GetRollingResistanceModel"></a>

#### GetRollingResistanceModel()

Get “Rolling Resistance Model” as a string.

- **Returns:**The returned value will be one of \[‘type\_1’, ‘type\_3’, ‘none’, ‘custom’\].

<a id="generated.RAPhysics.GetSearchDistanceMultiplier"></a>

#### GetSearchDistanceMultiplier()

Get the value of “Search Distance Multiplier”.

<a id="generated.RAPhysics.GetSphThermalTransferModel"></a>

#### GetSphThermalTransferModel()

Get “Sph Thermal Transfer Model” as a string.

- **Returns:**The returned value will be one of \[‘cleary’, ‘custom’\].

<a id="generated.RAPhysics.GetTangentialForceModel"></a>

#### GetTangentialForceModel()

Get “Tangential Force Model” as a string.

- **Returns:**The returned value will be one of \[‘elastic\_coulomb’, ‘coulomb\_limit’, ‘mindlin\_deresiewicz’, ‘custom’\].

<a id="generated.RAPhysics.GetThermalCorrectionModel"></a>

#### GetThermalCorrectionModel()

Get “Thermal Correction Model” as a string.

- **Returns:**The returned value will be one of \[‘none’, ‘morris\_et\_al\_area’, ‘morris\_et\_al\_area\_time’\].

<a id="generated.RAPhysics.GetUpdateDistanceMultiplier"></a>

#### GetUpdateDistanceMultiplier()

Get the value of “Update Distance Multiplier”.

<a id="generated.RAPhysics.GetUseRadlEtAl"></a>

#### GetUseRadlEtAl()

Get the value of “Use Radl Et Al”.

<a id="generated.RAPhysics.GetValidAdhesionModelValues"></a>

#### GetValidAdhesionModelValues()

Get a list of all possible values for “Adhesion Model”.

- **Returns:**The returned list is \[‘none’, ‘constant’, ‘linear’, ‘JKR’, ‘custom’\].

<a id="generated.RAPhysics.GetValidImpactEnergyModelValues"></a>

#### GetValidImpactEnergyModelValues()

Get a list of all possible values for “Impact Energy Model”.

- **Returns:**The returned list is \[‘default’, ‘custom’\].

<a id="generated.RAPhysics.GetValidNormalForceModelValues"></a>

#### GetValidNormalForceModelValues()

Get a list of all possible values for “Normal Force Model”.

- **Returns:**The returned list is \[‘linear\_hysteresis’, ‘linear\_elastic\_viscous’, ‘damped\_hertzian’, ‘custom’\].

<a id="generated.RAPhysics.GetValidRestitutionModelValues"></a>

#### GetValidRestitutionModelValues()

Get a list of all possible values for “Restitution Model”.

- **Returns:**The returned list is \[‘constant’, ‘velocity\_dependent’\].

<a id="generated.RAPhysics.GetValidRollingResistanceModelValues"></a>

#### GetValidRollingResistanceModelValues()

Get a list of all possible values for “Rolling Resistance Model”.

- **Returns:**The returned list is \[‘type\_1’, ‘type\_3’, ‘none’, ‘custom’\].

<a id="generated.RAPhysics.GetValidSphThermalTransferModelValues"></a>

#### GetValidSphThermalTransferModelValues()

Get a list of all possible values for “Sph Thermal Transfer Model”.

- **Returns:**The returned list is \[‘cleary’, ‘custom’\].

<a id="generated.RAPhysics.GetValidTangentialForceModelValues"></a>

#### GetValidTangentialForceModelValues()

Get a list of all possible values for “Tangential Force Model”.

- **Returns:**The returned list is \[‘elastic\_coulomb’, ‘coulomb\_limit’, ‘mindlin\_deresiewicz’, ‘custom’\].

<a id="generated.RAPhysics.GetValidThermalCorrectionModelValues"></a>

#### GetValidThermalCorrectionModelValues()

Get a list of all possible values for “Thermal Correction Model”.

- **Returns:**The returned list is \[‘none’, ‘morris\_et\_al\_area’, ‘morris\_et\_al\_area\_time’\].

<a id="generated.RAPhysics.GetVolumeFractionLimit"></a>

#### GetVolumeFractionLimit()

Get the value of “Volume Fraction Limit”.

<a id="generated.RAPhysics.SetAdhesionModel"></a>

#### SetAdhesionModel(value: str)

Set the value of “Adhesion Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘none’, ‘constant’, ‘linear’, ‘JKR’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Adhesion Model” option.

<a id="generated.RAPhysics.SetClosePackingVolumeFraction"></a>

#### SetClosePackingVolumeFraction(value: str | float)

Set the value of “Close Packing Volume Fraction”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.

<a id="generated.RAPhysics.SetEnableCoarseGrainModeling"></a>

#### SetEnableCoarseGrainModeling(value: bool)

Set the value of “Enable Coarse Grain Modeling”.

- **Parameters:****value** – The value to set.

<a id="generated.RAPhysics.SetEnableThermalModel"></a>

#### SetEnableThermalModel(value: bool)

Set the value of “Enable Thermal Model”.

- **Parameters:****value** – The value to set.

<a id="generated.RAPhysics.SetExponentLimit"></a>

#### SetExponentLimit(value: str | float)

Set the value of “Exponent Limit”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.

<a id="generated.RAPhysics.SetGravityStartTime"></a>

#### SetGravityStartTime(value: str | float, unit: str | None = None)

Set the value of “Gravity Start Time”.

- **Parameters:**
    - **value** – The value to set. This value can be an expression with input variables or float type.
    - **unit** – The unit for value. If no unit is provided, value is assumed to be in “s”.

<a id="generated.RAPhysics.SetGravityStopTime"></a>

#### SetGravityStopTime(value: str | float, unit: str | None = None)

Set the value of “Gravity Stop Time”.

- **Parameters:**
    - **value** – The value to set. This value can be an expression with input variables or float type.
    - **unit** – The unit for value. If no unit is provided, value is assumed to be in “s”.

<a id="generated.RAPhysics.SetGravityXDirection"></a>

#### SetGravityXDirection(value: str | float, unit: str | None = None)

Set the value of “Gravity X Direction”.

- **Parameters:**
    - **value** – The value to set. This value can be an expression with input variables or float type.
    - **unit** – The unit for value. If no unit is provided, value is assumed to be in “m/s2”.

<a id="generated.RAPhysics.SetGravityYDirection"></a>

#### SetGravityYDirection(value: str | float, unit: str | None = None)

Set the value of “Gravity Y Direction”.

- **Parameters:**
    - **value** – The value to set. This value can be an expression with input variables or float type.
    - **unit** – The unit for value. If no unit is provided, value is assumed to be in “m/s2”.

<a id="generated.RAPhysics.SetGravityZDirection"></a>

#### SetGravityZDirection(value: str | float, unit: str | None = None)

Set the value of “Gravity Z Direction”.

- **Parameters:**
    - **value** – The value to set. This value can be an expression with input variables or float type.
    - **unit** – The unit for value. If no unit is provided, value is assumed to be in “m/s2”.

<a id="generated.RAPhysics.SetImpactEnergyModel"></a>

#### SetImpactEnergyModel(value: str)

Set the value of “Impact Energy Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘default’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Impact Energy Model” option.

<a id="generated.RAPhysics.SetNormalForceModel"></a>

#### SetNormalForceModel(value: str)

Set the value of “Normal Force Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘linear\_hysteresis’, ‘linear\_elastic\_viscous’, ‘damped\_hertzian’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Normal Force Model” option.

<a id="generated.RAPhysics.SetNumericalSofteningFactor"></a>

#### SetNumericalSofteningFactor(value: str | float)

Set the value of “Numerical Softening Factor”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.

<a id="generated.RAPhysics.SetRestitutionModel"></a>

#### SetRestitutionModel(value: str)

Set the value of “Restitution Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘constant’, ‘velocity\_dependent’\].
- **Raises:****RockyApiError** – If value is not a valid “Restitution Model” option.

<a id="generated.RAPhysics.SetRollingResistanceModel"></a>

#### SetRollingResistanceModel(value: str)

Set the value of “Rolling Resistance Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘type\_1’, ‘type\_3’, ‘none’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Rolling Resistance Model” option.

<a id="generated.RAPhysics.SetSearchDistanceMultiplier"></a>

#### SetSearchDistanceMultiplier(value: str | float)

Set the value of “Search Distance Multiplier”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.

<a id="generated.RAPhysics.SetSphThermalTransferModel"></a>

#### SetSphThermalTransferModel(value: str)

Set the value of “Sph Thermal Transfer Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘cleary’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Sph Thermal Transfer Model” option.

<a id="generated.RAPhysics.SetTangentialForceModel"></a>

#### SetTangentialForceModel(value: str)

Set the value of “Tangential Force Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘elastic\_coulomb’, ‘coulomb\_limit’, ‘mindlin\_deresiewicz’, ‘custom’\].
- **Raises:****RockyApiError** – If value is not a valid “Tangential Force Model” option.

<a id="generated.RAPhysics.SetThermalCorrectionModel"></a>

#### SetThermalCorrectionModel(value: str)

Set the value of “Thermal Correction Model”.

- **Parameters:****value** – The value to set. Must be one of \[‘none’, ‘morris\_et\_al\_area’, ‘morris\_et\_al\_area\_time’\].
- **Raises:****RockyApiError** – If value is not a valid “Thermal Correction Model” option.

<a id="generated.RAPhysics.SetUpdateDistanceMultiplier"></a>

#### SetUpdateDistanceMultiplier(value: str | float)

Set the value of “Update Distance Multiplier”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.

<a id="generated.RAPhysics.SetUseRadlEtAl"></a>

#### SetUseRadlEtAl(value: bool)

Set the value of “Use Radl Et Al”.

- **Parameters:****value** – The value to set.

<a id="generated.RAPhysics.SetVolumeFractionLimit"></a>

#### SetVolumeFractionLimit(value: str | float)

Set the value of “Volume Fraction Limit”.

- **Parameters:****value** – The value to set. This value can be an expression with input variables or float type.