Effectiveness of banding pipes and cylindrical shells

The effect of the stress-state parameter m and the mechanical properties of the material in the pipe wall (coefficients A and n) on banding efficiency E_0.2 is demonstrated from the standpoint of metal savings in pipe production. It is established that a specific value of the parameter m, which ensures the attainment of (E_0.2)_max, exists for each material; in this case, the value of m_opt decreases with decreasing indicator n of the extent to which the material has hardened and increasing coefficient A. In this case, (E_0.1)_max also decreases, and from the standpoint of creation of designs of minimum weight, banding is no longer effective for high-strength steels after quenching and tempering.

Relationships are derived for evaluating banding efficiency from the standpoint of a maximum increase in working pressure in a pipe without increasing its wall thickness. It is demonstrated that the maximum increase in working pressure in a pipe subject to banding increases only with increasing indicator n of the degree of hardening of the wall material (with increasing uniform plastic deformation during the testing of specimens of pipe-wall material in axial tension); in this case, an increase of more than a factor of two in the working pressure of a banded pipe is possible when n>0.265.