3D Stress Tensors

The general three-dimensional state of stress consists of three unequal principal stresses acting at a point. This is called a triaxial state of stress. If two of the three principal stresses are equal, the state of stress is known
as cylindrical, while if all three principal stresses are equal, the state of stress is said to be hydrostatic, or spherical.The determination of the principal stresses for a three-dimensional state of stress in terms of the stresses acting on an arbitrary cartesiancoordinate system is an extension of the method described.The general three-dimensional state of stress consists of three unequal principal stresses acting at a point. This is called a triaxial state of stress.
If two of the three principal stresses are equal, the state of stress is known as cylindrical, while if all three principal stresses are equal, the state of stress is said to be hydrostatic, or spherical. The determination of the principal stresses for a three-dimensional state of stress in terms of the stresses acting on an arbitrary cartesian coordinate system is an extension of the method described.