The research of local tension in the average zone of the previously stressed steel beam, at action of the concentrated force

The article considers calculation of the local tension arising from action of the concentrated force applied in a zone of the maximum bending moment of the steel beam, previously stressed by the wall stretching. Values of multipliers for determination of local tension are found in previously stressed beam and in a beam without preliminary tension. The authors have received the general expression of normal tension in the cross section of a wall obtained for previously stressed beams. They have also found the expressions of normal tension for optimum geometrical parameters of previously stressed beam of double-T cross section. It is established that preliminary tension reduces local normal tension on an X-axis to 35% from external loading in comparison with a beam without preliminary tension.