Modal Analysis And Experimental Research Of Twin-Shaft Mixer

Concrete is one of the most widely used civil engineering materials,which is required by the state to prepare high-performance concrete while saving resources and protecting the environment.Twin-shaft vibration mixer is a high-performance concrete production equipment based on the vibration mixing theory,which is still in the stage of popularization and application at home and abroad,but it has shown obvious technical advantages in the engineering construction.Therefore,the research and analysis of twin-shaft vibration mixer has strong practical significance and engineering application value.In this paper,the vibration response and vibration characteristics of the main components of the twin-shaft vibration mixer are studied and analyzed through the vibration test and ANSYS software.The main research contents of the thesis are as follows:1.The model of the mixing device is established,and the modal analysis and technical improvement are carried out.The model is established,the equivalent stiffness of the support is analyzed,and the first six modal modes and frequencies are obtained by modal analysis.There is a big difference between the modal frequency and the working frequency,which will not cause resonance.The first two modes have low frequencies（15.739Hz、18.841Hz）,and will pass through the resonance region during the starting stage.The vibration shaft is improved and analyzed by changing the support stiffness,the excitation mode and the structure of the shaft.The first mode frequency can be increased to 86.6Hz by changing the excitation mode.2.The steady-state and transient vibration response of the vibration stirring device is analyzed.The harmonic response analysis is carried out,and the response under different excitation is compared and analyzed.It is found that 2mm is the appropriate excitation displacement.Through the transient analysis of the dangerous state of the device,the transient response of the vibration mixing device is obtained,and the strength of the structure is checked.3.The test scheme of the twin-shaft vibration mixer is designed,and the vibration signals of the main components under different working conditions are obtained and processed.In the experiment,the excitation device of the mixer itself is used as the excitation source,and the vibration signals of several measuring points are obtained by grouping different working conditions and components.4.The vibration of the agitator shaft in the start-up and stop stage is more violent.The signal characteristics of this stage are obtained by time-frequency analysis.The frequency characteristics are similar to the modal analysis results,which verify the correctness of the simulation.There are significant vibration peaks in the start and stop stages,and the vibration of the mixing shaft is more intense when it stops.The maximum acceleration and displacement peak value in this stage are 101.8 m?s^-2 and 4.96mm.5.The vibration signals of the mixing shaft under the stable vibration state are analyzed in time and frequency domain,and the vibration law and axis track law of the mixing shaft are revealed.The vibration performance of the mixer is evaluated with reasonable indexes.In the stable vibration stage,the acceleration of the mixing shaft is smaller at both ends and larger in the middle,and the acceleration is more than 20 m?s^-2,which meets the design requirements.The vibration energy is concentrated in their working frequencies:29.3Hz,31.25Hz.The displacement is obtained by the second integration of acceleration signal,and the vibration intensity is obtained by this calculation.The maximum value is 3.5,which meets the design requirements.6.The vibration parameters and response characteristics of the mixing arm are obtained.When the vibration is stable,the vibration intensity of the mixing arm is close to that of the mixing shaft,and the energy is concentrated in the working frequency.The vibration of the mixing arm at both ends of the mixing shaft is weak,and the vibration of the mixing arm in the middle is strong,with the maximum acceleration of 28.8.The vibration amplitude at the top of the mixing arm is large,slightly greater than 1mm.