Evaluate the acceleration and the predominant frequency of the truck bed on local roads and investigate the effective parameters in vibration

Abstract

Fruit packaging is an essential factor in reducing the mechanical damages caused by transportation. Accurate information on the transportation status of any region helps packaging designers to reproduce a more precise simulation of the existing conditions. This study was aimed to analyze the vibration acceleration of truck beds during transportation on local roads. For this, a wireless sensor network combined of three sensor nodes with a tri-axial accelerometer was used to measure the instant acceleration on the front and rear bed of the trucks equipped with leaf-spring suspensions. Acceleration values were three-dimensionally received by the sink node and recorded in a laptop. The average power spectral density (PSD) levels were computed for the local roads. Increasing the speed from 70 to 90 km/h increased the maximum PSD from 0.193 to 0.340 G2/Hz. Compared to the ASTM 4728 standard, the PSD levels of the trucks with spring suspension on local roads were higher in 1 to 35 Hz and lower in 35 to 200 Hz. The highest PSD values occurred at frequencies below 6 Hz and the frequency range of 3-4 Hz was determined as the predominant frequency on local roads. The average RMSG values in the vertical direction were 0.654 G for heavy trucks. In this study, the effects of road type, speed, direction, and location of package on vibration level were also discussed in detail. The findings can be applied to simulate the realistic transportation modes of the packaged fruit in lab-programmable-vibration tables.