Study On Structural Optimization And Interior Noise Control Of The Light Truck Cab

A truck cab is chosen as the research object in this paper,and a series of studies about optimization of structural lightweight and internal noise control are done on the basis of method of combining finite element simulation and experiment.A credible structure FE model of a cab is built and the model is verified by test.The main statics performances,including bending and torsional stiffness are analyzed.Also the speedup braking and swerve working conditions are calculated to find the stress concentration.In the lightweight model,the weight coefficients of constraint responses are determined through the analytic hierarchy process(AHP).Based on these,a concept of weighted relative sensitivity is proposed.With the results of weighted relative sensitivity analysis,the design variables and its optimization directions are identified,which can promote the accuracy of the optimization variable selection and improve the calculation efficiency in the process of optimization.Without reduction on the main static and dynamic performance of the cab,thickness of cab components is optimized with the total mass of the cab reducing by 8.7% and the main static and dynamic performance rising in different degrees.With building acoustic finite element model of the cab,the result of NTF experiment is compared with simulation results to verify the correct of this model.Using the coupling acoustic finite element model,the inherent characteristics of acoustic of the cab are calculated and the main frequency points of peak acoustic pressure are identified,which can influence the quality of sound obviously.Taking advantage of the panel analysis method with ATV and The modal contribution analysis method with MATV to analyze the acoustic contribution,the panels and modals are identified,which contribute to noise peak obviously and make the direction of quadratic optimization evident.In order to control the level of noise of quantitative cab,firstly,on the basis of the method of topology optimization,the beams should be added to the ceiling of the cab with more low-order modes to polish up the local stiffness of the ceiling.Then with establishing the FE model of the free damp layer and calculating the whole cell strain of the cab,the comprehensive modal strain energy of the main panel of cab is obtained under the panel contribution and modal contribution.And based on this,the free damp layer of the panel is optimized.With the quadratic optimization,the peak value of the considered sound pressure reduces,and the expected effects of noise control are achieved.