RotationTensor Class Reference

This is a RealTensor version of a rotation matrix It is instantiated with the Euler angles, which are measured in degrees. More...

#include <RotationTensor.h>

Inheritance diagram for RotationTensor:

Public Types
enum	Axis { XAXIS = 0, YAXIS, ZAXIS }
	axis for single axis rotation constructor More...

Public Member Functions
	RotationTensor (Axis axis, Real angle)
	single axis rotation (in degrees) More...
	RotationTensor (const RealVectorValue &euler_angles)
	fills according to Euler angles (measured in degrees) More...
void	update (Axis axis, Real angle)
	reforms the rotation matrix according to axis and angle. More...
void	update (const RealVectorValue &euler_angles)
	reforms the rotation matrix according to the Euler angles. More...

Detailed Description

This is a RealTensor version of a rotation matrix It is instantiated with the Euler angles, which are measured in degrees.

R = Z0 *X1 * Z2 where Z0 = anticlockwise rotation about Z axis through euler_angles(0) degrees where X1 = anticlockwise rotation about X axis through euler_angles(1) degress where Z2 = anticlockwise rotation about Z axis through euler_angles(2) degrees or an axis, angle pair where the angle is taken anticlockwise in degrees

Definition at line 30 of file RotationTensor.h.

Member Enumeration Documentation

Axis

enum RotationTensor::Axis

axis for single axis rotation constructor

Enumerator
XAXIS
YAXIS
ZAXIS

Definition at line 34 of file RotationTensor.h.

  {
    XAXIS = 0,
    YAXIS,
    ZAXIS
  };

Constructor & Destructor Documentation

RotationTensor() [1/2]

RotationTensor::RotationTensor	(	Axis	axis,
		Real	angle
	)

single axis rotation (in degrees)

Definition at line 13 of file RotationTensor.C.

{ update(axis, angle); }

RotationTensor() [2/2]

RotationTensor::RotationTensor

(

const RealVectorValue &

euler_angles

)

fills according to Euler angles (measured in degrees)

Definition at line 15 of file RotationTensor.C.

{ update(euler_angles); }

Member Function Documentation

update() [1/2]

void RotationTensor::update	(	Axis	axis,
		Real	angle
	)

reforms the rotation matrix according to axis and angle.

Definition at line 18 of file RotationTensor.C.

Referenced by ComputeElasticityTensorCP::computeQpElasticityTensor(), and RotationTensor().

{
  zero();

  RealVectorValue a;
  a(axis) = 1.0;

  const Real s = std::sin(angle * libMesh::pi / 180.0);
  const Real c = std::cos(angle * libMesh::pi / 180.0);

  // assemble row wise
  _coords[0] = a * RealVectorValue(1.0, -c, -c);
  _coords[1] = a * RealVectorValue(0.0, 0.0, s);
  _coords[2] = a * RealVectorValue(0.0, -s, 0.0);

  _coords[3] = a * RealVectorValue(0.0, 0.0, -s);
  _coords[4] = a * RealVectorValue(-c, 1.0, -c);
  _coords[5] = a * RealVectorValue(s, 0.0, 0.0);

  _coords[6] = a * RealVectorValue(0.0, s, 0.0);
  _coords[7] = a * RealVectorValue(-s, 0.0, 0.0);
  _coords[8] = a * RealVectorValue(-c, -c, 1.0);
}

update() [2/2]

void RotationTensor::update

(

const RealVectorValue &

euler_angles

)

reforms the rotation matrix according to the Euler angles.

Definition at line 43 of file RotationTensor.C.

{
  const Real phi_1 = euler_angles(0) * (libMesh::pi / 180.0);
  const Real Phi = euler_angles(1) * (libMesh::pi / 180.0);
  const Real phi_2 = euler_angles(2) * (libMesh::pi / 180.0);

  const Real c1 = std::cos(phi_1);
  const Real c2 = std::cos(Phi);
  const Real c3 = std::cos(phi_2);

  const Real s1 = std::sin(phi_1);
  const Real s2 = std::sin(Phi);
  const Real s3 = std::sin(phi_2);

  // doing a Z1, X2, Z3 rotation
  // RealTensorValue is formed row-wise

  _coords[0] = c1 * c3 - c2 * s1 * s3;  // R11
  _coords[3] = -c1 * s3 - c2 * c3 * s1; // R12
  _coords[6] = s1 * s2;                 // R13

  _coords[1] = c3 * s1 + c1 * c2 * s3; // R21
  _coords[4] = c1 * c2 * c3 - s1 * s3; // R22
  _coords[7] = -c1 * s2;               // R23

  _coords[2] = s2 * s3; // R31
  _coords[5] = c3 * s2; // R32
  _coords[8] = c2;      // R33
}

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The documentation for this class was generated from the following files:

• tensor_mechanics/include/utils/RotationTensor.h
• tensor_mechanics/src/utils/RotationTensor.C