Structural Acoustic Field Analysis And Low Noise Design Of Construction Machinery Cabins

Construction machinery noise not only affects the surrounding environment,but also affects the driver.The influence of the noise on the driver must be analyzed,evaluated and improved in the preliminary design stage.The low frequency noise of 20?200Hz is difficult to be weakened among the noise,and it have the greatest impact on the driver's work.This paper will carry out the structural acoustic field analysis of the cabin of a certain loader,and the analysis method of the acoustic field in the cabin of the engineering machinery cab is put forward by experiment and simulation.Detailed research contents and results of this dissertation are as follows:(1)Taking the cabin of loader as an example,the evaluation criteria of cab noise vibration are established.Through the experiment of cabin,we found the noise vibration problem.The finite element model of the cab structure is established,and the modal of cab is obtained by simulation.Then the reliability of the finite element model is verified by comparing with the experimental modal.At the same time the stiffness of cab glass plate was optimized.(2)The acoustic modal and vibro-acoustic modal of the loader's cab was analyzed.The simulation model is separately established to analyse the structure-borne and airborne noise.The integrated model of the cabin is established to analyze the sound field of the cab.It can be concluded that the cabin interior noise is equal to the structure-borne and airborne noise.(3)Low noise design of loader cab.According to the relevant theory and practice of loader cabin acoustic test,it is difficult to reduce low-frequency noise.Considering the feasibility,economy and lightweight design,through theoretical and experimental to select the better sound-absorbing material and damping material.Then these materials are applied to the design of low noise cabin.Moreover,the integrated sound field model of cabin was established,and the thickness optimization of the important plates structure was taken as the driver ear pressure response curve for target.Through the simulation it can see the good effect of low noise design,the maximum sound pressure level was decreased by 3.37dB,the total sound pressure is reduced by 2.93dB.(4)The innovation of this paper was the two synthesis,one was the synthesis of the structure-borne and airborne noise.The second was the low noise design of the synthesis of the sound absorbing material,damping material and the important optimized plates.