Determination of the direction of the principal stresses in the elements of steel structures by the values of the coercive force

The change of values of circular diagram of the coercive force on the magnetization angle at the transition of loading scheme of I-beam made of steel 10 (P1.1.Z.AN) from symmetric bending to bending with constrained torsion  at elastic deformations in the compression zone was studied. The necessity of constructing a circular diagram of the coercive force from the magnetization angle in the control zone to obtain information about the direction of the principal stresses when determining the stress-strain state of steel structure is substantiated.