Simulated In-transit Vibration Damage to Watermelons
Simulated In-transit Vibration Damage to Watermelons
复制标题
模拟西瓜运输途中的振动损伤
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
S. Rafie
中科院分区：
文献类型：
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作者：
F. Shahbazi;A. Rajabipour;S. Mohtasebi;S. Rafie
车辆在道路运输过程中产生的振动对农产品尤其是蔬菜水果的损伤过程有着重要的影响。弹性模量是水果最重要的力学性质之一，其变化规律可作为水果在运输过程中损伤的判据之一。研究了振动参数（频率、加速度和持续时间）和果实在仓中的位置对西瓜损伤的影响。首先，对某型货车的振动频率和加速度进行了测量，得到了货车在运输过程中振动频率和加速度的分布范围。其次，利用实验室振动器对西瓜在运输过程中的损伤进行了研究。损伤被描述为试验前后西瓜（果肉和船体）的弹性模量的差异。根据在货车上的测量结果，振动频率平均值为7.50 Hz和13.0 Hz，分别为5-10 Hz和10-15 Hz的频率间隔。此外，0.25-0.50 g和0.50-0.75 g区间的振动加速度平均值分别为0.30 g和0.70 g。振动频率和加速度平均值用于振动模拟。振动持续时间为30和60分钟，并测量了西瓜在仓中顶部、中部和底部位置的损伤。试验结果表明，振动频率、振动加速度、振动持续时间和果实位置作为控制变量，对果实损伤有极显著影响（P< 0.01）。对西瓜果肉的伤害高于西瓜船体。频率为7.5 Hz，加速度为0.70 g，持续时间为60分钟的振动造成更高的损坏水平。仓顶果实的受害率显著高于仓中和仓底果实（P< 0.05）。
Vibration generated by vehicles during road transport has an important effect on the agricultural products damage process, particularly vegetable and fruit. Modulus of elasticity is one of the most important mechanical properties of fruits and its variation can be described as one of the damage criteria during transportation. This research was conducted to evaluate the effects of vibration parameters (frequency, acceleration and duration) and fruit position in the bin, on watermelon damage. At first, vibration frequency and acceleration were measured on the different points of a truck-bed in order to obtain the range of vibration frequency and acceleration distribution during transportation. Second, a laboratory vibrator was used to obtain some factors influencing damage during watermelons transportation. The damage was described as a difference in the modulus of elasticity of the watermelon (flesh and hull) before and after the test. According to the results measured on the truck-bed, the vibration frequency mean values were 7.50 Hz and 13.0 Hz for 5-10 Hz and 10-15 Hz frequency intervals, respectively. Furthermore, vibration acceleration mean values were 0.30 g and 0.70 g for 0.25-0.50 g and 0.50-0.75 g intervals, respectively. Vibration frequency and acceleration mean values were used for vibration simulation. Vibration durations were 30 and 60 minutes and damage was measured for watermelons at the top, middle and bottom positions in the bin. Laboratory studies indicated that, vibration frequency, vibration acceleration, vibration duration, and fruit position, which were taken into consideration as controlled variable parameters, significantly affected the damage (P< 0.01). Damage to the watermelon flesh was higher than watermelon hull. Vibration with a frequency of 7.5 Hz, acceleration of 0.70 g, and duration of 60 minutes caused higher damage levels. Fruits located at the top of the bin showed more damage than those in middle and bottom positions (P< 0.05).