Fatigue Crack Detection Technology And Experimental Research Of The Hoisting Equipment Based On Lamb Wave

Lifting equipment for the modern construction,providing huge convenient and efficient service,has become an indispensable industrial economic construction of lifting equipment.However,the equipment will bring heavy economic losses and even casualties,the social impact is harsh once the accident happens.Due to the long service life and poor operating environment,lifting equipment is prone to fatigue cracks in the use of the process.Crack is one of the most common failure modes of lifting equipment metal structure,and it is common for accidents such as fatigue failure and fatigue fracture due to crack propagation.It is of great significance to study the reasonable health monitoring technology for the crack to ensure the safe operation of the lifting equipment.As the active health monitoring technology based on active Lamb wave has the advantages of high sensitivity,wide application range,strong anti-interference ability,fast signal acquisition and processing methods,it has great application value.In order to improve the safety of lifting equipment,prevent the occurrence of accidents and provide technical support for fatigue crack monitoring,this paper studies the fatigue crack monitoring technology of lifting gear based on Lamb wave.The main contents are as follows:(1)Through the relevant literature retrieval and research,we can understand the harm of fatigue crack of lifting equipments and the existing detection and testing technology at home and abroad,and expound the importance of fatigue crack monitoring for lifting equipments.The research compares the internal situation on Lamb wave fatigue crack monitoring with the external.And the necessity of studying the fatigue crack monitoring technology of lifting gear based on Lamb wave is expounded.(2)Based on the basic theory of Lamb wave,the propagation model of Lamb wave and the solution equation of Lamb wave velocity and phase velocity are given from the perspective of elastic dynamics.The dispersion properties of Lamb wave are obtained.On this basis,this paper studies the Lamb Wave excitation method in detail.(3)According to the parameters and geometric parameters of the crane web material,the finite element simulation model is established and the numerical simulation of the propagation characteristics of the Lamb wave signal is carried out.The correctness of the Lamb wave fatigue crack simulation results is confirmed by the theoretical analysis of the Lamb wave signal.At the same time,the theoretical results of Lamb wave fatigue crack monitoring are further verified by comparing the model defects,and the basis for the Lamb wave signal excitation parameter setting is provided for the experimental study.(4)An experimental system of fatigue crack monitoring for lifting equipment based on Lamb wave is integrated.The function and selection principle of each subsystem are expounded.The working principle and main performance of piezoelectric sensor are introduced in detail.The ellipse localization method is used as defect diagnosis technology.(5)Based on the Lamb wave,the fatigue crack detection system is built.The testing experiment of the fatigue crack is used to verify the feasibility and accuracy of fatigue crack detection.It provides technical support and experimental basis for fatigue crack monitoring of lifting gear based on Lamb wave.