[Waleed Khalid]

Hi,

I have created two volScalarField,
volScalarField MAXprincipalstress
(
IOobject
(
"MAXprincipalstress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(0.5 * (sigmaxx + sigmayy) + sqrt( sqr((sigmaxx- sigmayy) * 0.5 ) + sqr(sigmaxy)))

);

volScalarField Minprincipalstress
(
IOobject
(
"Minprincipalstress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(0.5 * (sigmaxx + sigmayy) - sqrt( sqr((sigmaxx- sigmayy) * 0.5 ) + sqr(sigmaxy)))

);

Now i want to compute third volScalarField from these two that are already created here. I am doing it like this.
volScalarField EquivalentStress
(
IOobject
(
"EquivalentStress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
sqrt(MAXprincipalstress(MAXprincipalstress - Minprincipalstress) * 0.5 )

);
But i am getting an error while compiling the code.
Error:
error: no match for call to ‘(Foam::volScalarField {aka Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>}) (Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >)’ 171 | sqrt(MAXprincipalstress(MAXprincipalstress - Minprincipalstress) * 0.5 ) | ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~

[olesen]

Try using a dimensionedScalar instead of the 0.5 and see if that helps.

[Sereff]

maybe try simply use:
sqrt((MAXprincipalstress - Minprincipalstress) * 0.5 )

instead of:
sqrt(MAXprincipalstress(MAXprincipalstress - Minprincipalstress) * 0.5 )

[Waleed Khalid]

Thanks, it work well But why this does not work?
sqrt(MAXprincipalstress(MAXprincipalstress - Minprincipalstress) * 0.5 )

[Waleed Khalid]

May be Open-foam, doesn't do arithmetic operations on more than two arrays? am i right?

[Waleed Khalid]

Here is the final code it works well thanks Sereff
volScalarField principalstress
(
IOobject
(
"principalstress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(0.5 * (sigmaxx + sigmayy) + 0.5 * sqrt( sqr(sigmaxx- sigmayy) + 4 * sqr(sigmaxy)))

);

volScalarField MAXprincipalstress
(
IOobject
(
"MAXprincipalstress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(0.5 * (sigmaxx + sigmayy) + sqrt( sqr((sigmaxx- sigmayy) * 0.5 ) + sqr(sigmaxy)))

);

volScalarField Minprincipalstress
(
IOobject
(
"Minprincipalstress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(0.5 * (sigmaxx + sigmayy) - sqrt( sqr((sigmaxx- sigmayy) * 0.5 ) + sqr(sigmaxy)))

);

volScalarField sigma_L
(
IOobject
(
"sigma_L",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
(MAXprincipalstress - Minprincipalstress)

);

volScalarField EquivalentStress
(
IOobject
(
"EquivalentStress",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
sqrt((MAXprincipalstress * sigma_L) * 0.5 )

);

[Sereff]

the error message

no match for call to ‘(Foam::volScalarField {aka Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>}) (Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> >)’ 171 | sqrt(MAXprincipalstress(MAXprincipalstress - Minprincipalstress) * 0.5 ) |

implies that the class you are invoking doesnt have a member function that matches the argument you are trying to pass, so in this case you are calling the constructor

MAXprincipalstress(some arguements)

and the argument you are passing along is

(MAXprincipalstress - Minprincipalstress) * 0.5  <--  some arguement

and this is of type

Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>>

which I guess does not match with the constructors defined for volScalarField class