Research On Automatic Identification Method For Mechanical Properties Decay Of Laminated Shell Structures

With continuous development of China's economic construction and the improvement of people's travel requirements,China's airport construction has entered a period of rapid development.Because cement concrete pavement has the advantages of high strength,good stability and good working performance,it has been widely used in airport runway paving in large and medium cities in China.However,in the process of use,there are many disease problems in the cement concrete pavement.Among them,the void of the bottom of the pavement is the most typical.Because the void disease is the direct predisposing factor of the pavement crack and the broken board disease,it seriously endangers the operation safety of the aircraft.Therefore,timely repair of the void area is particularly important,and accurate clearance identification is the premise and basis of the void repair.At present,the existing detection methods for void diseases can only be accurately identified in terms of detection of void location,and accurate identification of void range cannot be performed.This makes it impossible to assess the degree of damage at the bottom of the slab,so that it is impossible to perform targeted repair on the void disease.In view of the above situation,this paper conducts an in-depth study on the quantitative identification of voids.In this paper,the airport cement concrete pavement is taken as the research object,and a quantitative method for the underlying disease of multilayer shell structure is proposed.According to the evolution law of the void disease,it is proposed to use the equivalent void size to characterize the actual void range,so as to evaluate the damage degree of the base layer during severe voiding.It is proposed to use the inversion modulus value to evaluate the damage degree of the base layer in early evolution of void disease.Then,based on the quantitative method of multilayer shell structure underlying disease,using the secondary development function of ABABQUS software to establish three modules: parametric modeling module,parameter inversion module and user graphical interface module to realize automatic modeling,automatic parameter inversion and automatic parameter interface input function.On this basis,three modules are integrated to create the automatic identification software for the degradation of the mechanical properties of the multilayer shell structure,so as to realize the automatic identification of the quantitative identification of the void disease.Finally,using the measured data of the airport,the automatic identification software is used to evaluate the mechanical performance decay of the airport pavement,and the reasons for the large-scale modulus inversion error of the plate angle and the edge of the board are analyzed.The reason for the large inversion error of the void size are analyzed.