Effect Of Vibration Acceleration Transmissibility And Resonant Frequency On The Qualities Of Muskmelon During Transportation

The experiments were conducted under the conditions of different time and different frequency in vertical and horizontal vibration in order to find out the dynamic properties and the changes of qualities under the condition of resonant frequency, and also find out their effects both on the qualities during storage and the injury caused by the vibration. The DASP software was initiated combining with both window function and transferring function so as to record the acceleration amplitude and the acceleration transmissibility, as well as resonant frequency. The results show that,1. The vibration characteristics have great influence on the acceleration transfer ratio and the acceleration transmissibility will increase with the time extension. The acceleration transmissibility is large in the low-frequency situation and it may reach the maximum value with numbers of 2.1 and 1.4 respectively under vertical vibration of 4Hz. The results also show that vertical vibration are stronger effective on the fruits than that of horizonal vibration.2. There is the correlation between the change of muskmelon postharvest storage quality and acceleration transmissibility. Through the correlation analysis the three indexes of the increase in hardness, change of sugar dergee and the damage rate increased are positively correlation with the acceleration transmissibility under vertical frequency during the storage. That is to say the large vibration acceleration transmissibility, the hardness decreased faster, and the faster the soluble solids content was changed, the greater the damage rate was.3. Some useful signals may be picked up from many cluttered signals and obtained resonant frequency in sweeping frequency test through setting a certain interval with analysis by using the DASP software. The resonant frequency of muskmelons are very positive correlative to the fruit hardness with a correlation coefficient R2=0.9132.4. The qualities of muskmelon change with different time of vibration and vibration frequency during storage. Regardless of the resonant frequency or low frequency vibration of muskmelon firmness, soluble solids have a low trend, damage rate performance for increased significantly, and the damage rate caused by resonant frequency was significantly higher than that in low frequency.it can be workable through the use of appropriate packaging and the mode of transportion to avoid the resonant frequency and to minimize quality of muskmelon decay and prediction and prolong the shelf life during actual transportion.