Research On Tower Structural Damage Diagnostic Model Of The Tower Crane Based On The Map Features

Tower crane,as a large-scale and high-risk special equipment,is widely used in the construction industry.However,numerous accidents are caused by structural fatigue damage,main segments fracture,high strength bolt looseness of the tower and so on.To ensure the safety of tower crane operation,new requirements of damage detection effectiveness,accuracy and reliability are brought up.Therefore,how to monitor the damage quickly becomes one of the key links to ensure the safety of tower crane operation.This paper compiled the present experiment and practice in tower structure damage detection in our group,set up the mathematical description of tower structure damage feature maps and damage judgment methods,the main contents are as follows:(1)Build a mathematical model of the trajectory on the top of the tower.Use the ADAMS dynamic simulation model of the tower crane QTZ40 to obtain the trajectory map of the tower under different damages.Respectively base on Fourier descriptor,piecewise spline curve,time series spline curve and sum of 3 sine functions to study the description methods of the trajectory.And build a mathematical model of sum of 3 sine functions of the trajectory curve of the tower after synthetically comparing description results to realize the mathematical description of the trajectory curve.(2)Construct the judgment method of tower damage based on the mathematical model.By using the fitting function of Matlab,fit the model parameter under different damages and solve each parameter of the curve model.Then structure generalized space coordinate system by using of model parameter,and find out the tower damage state judgment method according to the spatial distribution of different model parameters,namely: the frequency of the main frequency function determines whether the damage occurs,the amplitude determines the type of damage.(3)Test the effectiveness of the tower damage judgment method by experiment.Establish a physical experiment platform that can be used to simulate the tower section to simulate different degree of damages,and read trajectory data on the top of the tower under different damages,and solve the actual values of the model parameters.Then verify the correctness of the judgment method by comparing the experimental parameters and simulation parameters(4)Get a new method to measure the length of the pendulum in theory.Design a simple method for measuring the theoretical length in view of the acquisition signal accuracy is one of the determinants of simple pendulum length.In a word,in this paper,we study the trajectory curve of on the top of the tower,build a mathematical model of the trajectory on the top of the tower,construct the judgment method of tower damage based on the mathematical model to recognize the damage of the tower crane quickly.