Search

We analyze the stressed state of pipeline T-joints in which the connecting pipe makes an angle of 90° or 45° with the main pipe under the action of torques and bending moments causing the out-of-plane torsion and bending of the T-joint. The influence of the angle of orientation of the connecting pipe on the behavior of the stress tensor is studied for various loading modes. For all investigated loading modes, we determine the stress concentration factors according to the Maxell-More theory of specific distortion strain energy.

1. Anomalous creep of the metastable alloy 000Kh18N10 has been found in the temperature range 273–20°K; this is due to peculiarities of the martensite-type phase transformation. 2. At liquid-helium temperatures there is no linear relationship between the creep deformation and log creep time or between log creep rate and deformation in the transient stage. The amount of creep depends to only a small extent on the applied stress.

1. An anomalous decrease in the yield point of the03Kh20N16AG6steel was observed for T < 60 °K. It is shown that the temperature of the anomaly fits into the graph representing the dependence of the temperature of anomalies on the nickel content of stainless steels with a nickel concentration of 8–25%. 2. It is also shown that the application of the external magnetic field H = 20 kOe results in a monotonic increase in the temperature dependence of the yield point in the temperature range of the anomaly observed at H = 0. 3. An anomaly of the linear thermal expansion coefficient of the03Kh20N16AG6steel was observed at low temperatures.