Analysis Of Transition Process Of Nonlinear Vibrating Beam With Cracks

Vibration machinery is an indispensable role in engineering.It is widely used in industry,agriculture,national defense and other aspects and daily life.Due to factors such as process,environment,etc.,it is inevitable that there will be tiny cracks on the structure in the use of vibrating machines.When the crack damage is serious,the equipment structure will be broken and cause serious damage,so it is very important to find the crack as soon as possible.This paper takes the crack problem of the beam structure of the single-axis inertial vibrating machine in the vibrating machine as an example to explore the effect of cracks on the dynamic response of the vibrating beam structure and provide theoretical support for crack diagnosis research.At present,in the research of dynamic response and fault diagnosis of vibration beam structure,most of them are based on the vibration signal under the stable operation state.While there are relatively few researches on the signal response during the transition process stage of switching between stationary and running states such as start and stop However,the high information content of the transition process signal is an important basis for comprehensively grasping the state of mechanical equipment.In this paper,through modeling and simulation,the dynamic response of the cracked vibration beam structure during the short-term transition process of start-up is studied with the trend of the degree of crack and the position of the crack,which provides a theoretical reference for the early diagnosis of cracks in vibration beam structures.It is conducive to the timely detection and treatment of cracks,which has greater theoretical significance and application value.In this paper,the crack problem of the complex nonlinear vibration beam structure is studied by means of equivalent modeling,dynamic analysis and time-frequency domain signal analysis.When designing simulation animations,establishing and solving dynamic models,comprehensively using Runge-Kutta numerical method,discrete Fourier transform and other theories,compiled a number of VB programs.And the visualization of the program is realized,vividly showing the dynamic model.And reasonably design the interface to intuitively reflect the time domain,frequency domain graphics and key values.This effectively innovates the technical method to explore the relationship between the crack and the response of the vibrating beam structure transition process.The cogitation of comparative verification is used throughout the text,and the research is carried out in the two major vibration systems: First,establish a dynamic model of the discretized system of a cracked vibration beam structure for key research.Simulate different start-up initial input motion signals,different structural parameters,different crack positions,and different crack degrees,then solve and analyze the response characteristics of displacement,velocity,acceleration,etc.in the time domain and frequency domain.Through multi-angle and multi-condition simulation and comparison,the influence of the degree of crack failure and the position of the crack on the transition process response of the vibration beam structure is explored,and the crack state of the structure is reflected from the vibration response.The study shows that the period and amplitude of the vibration response in the time domain will increase with the increase of the crack degree.In the frequency domain,the vibration response will appear "frequency amplitude change","frequency increase","frequency shift" and other changes with the change of crack degree and crack position;Second,establish the dynamic model of the elastic continuous system of the vibration beam structure with cracks,and simulate the crack failure situation as a variable cross-section continuous beam structure problem model.Under the spring model,it is concluded that the amplitude and period of the displacement response of each node position of the vibration beam structure increase with the increase of the crack degree.It echoes the displacement response results explored under the condition of the discretized system vibration model.In addition,this method is also suitable for simple beam models with similar structures,which expands the research space.This paper explores the relationship between the crack failure of the vibrating beam structure and the dynamic response of the transition process through the comparison and verification of multiple models,multiple conditions,and multiple angles.It provides an important theoretical reference and support for the early identification and diagnosis of cracks in vibrating beam structures,and has important theoretical significance.