Examples with SymmetricMatrix3d maspack.matrix.SymmetricMatrix3d used on opensource projects

Example 36 with SymmetricMatrix3d

use of maspack.matrix.SymmetricMatrix3d in project artisynth_core by artisynth.

the class OgdenMaterial method computeStress.

public void computeStress(SymmetricMatrix3d sigma, SolidDeformation def, Matrix3d Q, FemMaterial baseMat) {
    double J = def.getDetF();
    double avgp = def.getAveragePressure();
    sigma.setZero();
    // Calculate Deviatoric left Cauchy-Green tensor
    def.computeDevLeftCauchyGreen(myB);
    Vector3d principalStretch = new Vector3d();
    Vector3d principalStretch2 = new Vector3d();
    Matrix3d principalDirection = new Matrix3d();
    // Calculate principal stretches and principal directions
    myB.getEigenValues(principalStretch2, principalDirection);
    for (int i = 0; i < 3; i++) {
        principalStretch.set(i, Math.sqrt(principalStretch2.get(i)));
    }
    // Calculate principal stresses
    for (int i = 0; i < 3; i++) {
        for (int n = 0; n < Nmax; n++) {
            if (myMu[n] != 0) {
                sigma.set(i, i, sigma.get(i, i) + myMu[n] / myAlpha[n] / J * (Math.pow(principalStretch.get(i), myAlpha[n])));
            }
        }
    }
    // Calculate stress tensor from principal stresses and directions
    sigma.mulLeftAndTransposeRight(principalDirection);
    sigma.deviator();
    sigma.m00 += avgp;
    sigma.m11 += avgp;
    sigma.m22 += avgp;
}

Example 37 with SymmetricMatrix3d

use of maspack.matrix.SymmetricMatrix3d in project artisynth_core by artisynth.

the class LinearMaterialBase method computeTangent.

@Override
public void computeTangent(Matrix6d D, SymmetricMatrix3d stress, SolidDeformation def, Matrix3d Q, FemMaterial baseMat) {
    // get spatial stiffness tensor
    getC(D);
    // rotate if corotated
    if (isCorotated()) {
        // need to rotate this tensor from linear frame into material one
        RotationMatrix3d R = def.getR();
        if (R == null) {
            Matrix3d F = def.getF();
            R = computeRotation(F, null);
        }
        // R rotates from material frame to the spatial one. Transpose
        // of R rotates from spatial frame to material one.
        TensorUtils.unrotateTangent(D, D, R);
    }
}

Example 38 with SymmetricMatrix3d

use of maspack.matrix.SymmetricMatrix3d in project artisynth_core by artisynth.

the class LinearMaterialBase method computeStress.

public void computeStress(SymmetricMatrix3d sigma, SolidDeformation def, Matrix3d Q, FemMaterial baseMat) {
    RotationMatrix3d R = def.getR();
    Matrix3d F = def.getF();
    // cauchy strain, rotated if necessary
    if (myCorotated) {
        if (R == null) {
            R = computeRotation(F, sigma);
        } else {
            // remove rotation from F
            sigma.mulTransposeLeftSymmetric(R, F);
        }
    } else {
        sigma.setSymmetric(F);
    }
    sigma.m00 -= 1;
    sigma.m11 -= 1;
    sigma.m22 -= 1;
    multiplyC(sigma, sigma);
    // rotate stress back to original frame
    if (isCorotated()) {
        sigma.mulLeftAndTransposeRight(R);
    }
}