The Research Of The Prestress Testing System For Membrane Structure

To meet the need of a high-precision prestress measurement which is convenient for operation and reliable in theory for membrane structures,according to the material properties of the structural membranes,according to cable analogy theory and measurement method of cable pretension,for the determination of the membrane prestress is proposed in this paper. The approach combines out-plane displacement measurement and theoretical relations between the displacement and the initial prestress of the membrane.The idea is supported by appropriate formulas describing the pretension-displacement behavior of rectangle-shaped, stretched membranes under uniform normal load.Based on this technique,measuring system (instrument) is finally assembled.The measurement reliability and accuracy of the system are validated by the test.The main contents in this paper as below:1,The reasons of causing prestress are analyzed,the algorithm of prestress is selected, the total designing program of this system is confirmed.2,According to single-cable analogy theory,set up the mathematics model for rectangle-shaped,stretched membrane.3,Mechanical structure and hardware are designed,and the software is compiled.4,Through the testing and examinations,it shows:the theory of this system is right,the performance of this system is reliable.The prestress on the membrane can be measured by this system effectively.It filled up the vacancy in this field in China,wihch opening membrane prestress testing system.If it is used widely,it will finish that time,which estimated the prestress just only depending on experiences.It will reinforce the . It will supply the amount gist for check and accept of membrane structure projects.It is advantaged to combine designing with construction in membrane structure.