Design Of Vibration Testing And Analysis System Based On LabVIEW

To solve the vibration and noise reduction problem of mechanical structures,this paper develops a vibration testing and analysis system to improve the dynamic characteristics of mechanical equipment,enhance the stability of vibration testing systems,improve the efficiency of system use and reduce the cost of testing systems.The vibration testing and analysis system can be used for experimental modal analysis of mechanical structures and vibration isolation effect detection of vibration isolation devices.The system can be used not only in practical engineering analysis,but also in teaching and scientific research.This study draws lessons from the current research results,and uses the modular design idea to divide the system architecture.The system is divided into three modules: vibration test data acquisition,vibration isolation effect detection and modal analysis.Vibration test data acquisition is mainly responsible for acquiring,processing the sensor signals in the vibration testing.In this paper,the method of force hammering is adopted.It has strong adaptability to the equipment excitation and data acquisition in different occasions.Modal analysis is mainly to study the dynamic characteristics of mechanical structures,to estimate the natural frequencies,damping ratios and modal modes of mechanical structures,so as to provide reference for structural fault diagnosis,vibration and noise reduction and design improvement.Vibration isolation effect detection can be realized through recording the vibration signals of the upper and lower layers of the isolation equipment,detecting the vibration level difference between the upper and lower layers of the isolation equipment,to judge the isolation effect of the equipment.In this study,each module is interdependent,and together constitutes a set of vibration testing and analysis system for mechanical structure and equipment.On the basis of studying the testing process and basic principle of experimental modal analysis,this paper deeply studies the key technologies such as high-speed synchronous data acquisition,signal processing,data storage,modal parameter analysis and so on.Combining the design ideas of vibration test and modal analysis system at home and abroad,vibration test and analysis system is developed based on Virtual Instrument Technology of LabVIEW platform.In modal parameter identification,many modal indicators are used to eliminate false modes.Two identification algorithms,least square complex exponential(LSCE)and frequency domain direct parameter identification(FDPI),are used to realize the accurate identification of modal parameters.In addition,through the octave analysis of vibration signal,the calculation method of vibration level is studied,and the vibration isolation effect and transmission characteristics of mechanical equipment are tested.Finally,the reliability of the system is verified by means of the authoritative third-party vibration analysis and research institute in China.Firstly,the modal test of the test workpiece designated by the third party is carried out,and the main modal parameters such as natural frequency and damping ratio of the test workpiece are obtained.The vibration isolation effect of a stone cutting machine and vibration isolator is tested.The results are consistent with the results of the third-party test.This shows that the method adopted in this study has high accuracy.The system developed in this study can be competent for modal testing and analysis of structures and vibration isolation effect detection of equipment,which has certain economic and scientific significance.