Added range to "density" parameter.

Author: SteveMaas1978

FEBioMech/FEElasticBeamMaterial.cpp

@@ -49,7 +49,7 @@ void FEElasticBeamMaterialPoint::Update(const FETimeInfo& timeInfo)
 
 //=======================================================================================
 BEGIN_FECORE_CLASS(FEElasticBeamMaterial, FEMaterial)
-	ADD_PARAMETER(m_density, "density")->setUnits(UNIT_DENSITY);
+	ADD_PARAMETER(m_density, FE_RANGE_GREATER(0.0), "density")->setUnits(UNIT_DENSITY);
 	ADD_PARAMETER(m_E , "E" )->setUnits(UNIT_PRESSURE);
 	ADD_PARAMETER(m_G , "G" )->setUnits(UNIT_PRESSURE);
 	ADD_PARAMETER(m_A , "A" )->setUnits(UNIT_AREA);

FEBioMech/FESolidMaterial.cpp

@@ -32,7 +32,7 @@ SOFTWARE.*/
 
 // Material parameters for FEElasticMaterial
 BEGIN_FECORE_CLASS(FESolidMaterial, FEMaterial)
-	ADD_PARAMETER(m_density, "density")->setUnits(UNIT_DENSITY)->MakeTopLevel(true);
+	ADD_PARAMETER(m_density, FE_RANGE_GREATER_OR_EQUAL(0.0), "density")->setUnits(UNIT_DENSITY)->MakeTopLevel(true);
 END_FECORE_CLASS();
 
 FESolidMaterial::FESolidMaterial(FEModel* pfem) : FEMaterial(pfem)