Initial Load and Strain
The initial stress means the stress before any loads, displacements, and initial strains have been applied.
The initial stress distribution is given as initial forces and moments in the local section directions.
In 2D the
x
and
y
components of moments disappear.
In a Timoshenko beam, the initial shear forces appear as independent quantities, and can also be specified.
The initial strain is the strain before any loads, displacements, and initial stresses have been applied. The initial axial strain distribution is given as initial curvature and initial axial strain
In 2D the
z
l
dependent term disappears. As initial strain for the torsional degree of freedom, the derivative of the twist angle,
is used.
In a Timoshenko beam it is also possible to set the initial values for the shear strains.
