Experiment And Numerical Analysis On Compensation Of Coated Fabrics Membrane Structure

In the actual construction,the pretension must be applied to the forming of the tension-membrane structure,so that the structure can produce the corresponding stiffness and shape to resist the external loads.The application of pre-tension is achieved by scaling the flat spread diaphragm according to the cutting reduction rate.To obtain a reasonable cutting reduction rate is an important prerequisite to ensure the safety and beauty of the whole structure.At present,there are relatively few studies on the cutting reduction rate in China,which is not conducive to the further healthy development of membrane structure.In this paper,the cutting reduction rate of coated fabrics is taken as the research object.Considering the construction process and mechanical characteristics,different testing schemes are carried out to determine the cutting reduction rate.Then the factors of influencing cutting reductions rates are discussed and the reasonable test scheme is put forward.The deformation characteristics of membrane materials are investigated.The deformation of membrane under loads is divided into four parts,crimp deformation,elastic deformation,plastic deformation and creep deformation.The deformation law of each part is analyzed,and the numerical calculation method of cutting reduction rate is put forward.The pretension distribution characteristics of the forming surface are discussed through the numerical analysis of the construction tension process and the stress relaxation behavior of the forming surface.Taking saddle surface as an example,the shape and pretension distribution of the formed surface after tension are obtained by using2 D scaling plane cutting plate as the initial condition.Taking the formed surface after tension as the initial surface,the stress relaxation analysis is carried out by using generalized Maxwell viscoelasticity.Compared with the designed pretension value,the stress distribution changes of membrane surface with time are analyzed.The feasibility of different methods for determining the cutting reduction rate is analyzed,which provides a theoretical basis for determining the cutting reduction rate.This paper presents the experimental method and numerical calculation method to determine the cutting reduction rate,and analyzes the influencing factors of the reduction rate,which makes up for the blank of the cutting reduction rate in the technical regulation.Through analyzing the mechanical characteristics of membrane surface,the validity of cutting reduction rate methods is verified.