Nondestructive Testing Method of Vertical Prestressed Finishing Twisted Steel Tension

Abstract

Based on the dynamic, selecting the vibration shape functions for obtaining the structural frequency, without using the differential operation of the conventional Rayleigh law which improved the calculation accuracy, the three-parameter model was built which include the frequency of the exposed segment, the segment length of the exposed steel reinforcements and anchorage segment increased stiffness coefficient. Meanwhile the validity of the three-parameter model was verified using finite element numerical simulation. The vertical pretensioning force of the box girder webs model was designed at laboratory. The natural frequency of vertical prestressing tendons exposed section was obtained through the high-frequency acceleration sensor which was set up at the top of the exposed section. Relying on experimental test data, the model which had the nonlinear relationship between the effective tensile force and anchorage segment increased stiffness coefficient was established.