Abstract: In order to explore the mechanical properties of pellet feed, this paper took 3 types of formula feed produced by feed industry for pig, poultry and fish as experiment samples, and conducted axial compression, radial compression and shear tests, respectively. Under the 3 different test methods, the ultimate strength of aquatic formula feed was the highest, followed by poultry compound feed, and pig formula feed was the lowest. With the increase of aspect ratio, the ultimate strength of radial compression and shear did not change much, and the ultimate strength of axial compression tended to decrease with the increase of aspect ratio. With the increase of moisture content, the ultimate strength of pellet feed increased first then decreased, and the ultimate strength had the maximum value. Feed category, test method and moisture content had significant effects on ultimate strength. Adopting Design-expert response surface method, this paper obtained the response surface relationship among target load, dwell time and powder content rate. The results showed that there was a linear relationship between the powder content of pellet compound feed, payload and dwell time. The payload and dwell time had a significant effect on powder content, and the effect of payload on content of powder was more significant than that of dwell time.

Key words: pellet feed, aspect ratio, moisture content, ultimate strength, powder content, response surface

摘要： 为了探究颗粒饲料力学特性，采集饲料企业生产的猪、禽和水产三大类配合饲料作为试验样品，对单颗粒饲料分别进行了轴向压缩、径向压缩和剪切试验。在三种不同的测试方式下水产配合饲料极限强度最大，禽配合饲料次之，猪配合饲料最小；随着长径比的增加，径向压缩极限抗张强度和剪切极限抗剪强度变化不大，轴向压缩极限抗压强度随着长径比的增加有减小的趋势；配合饲料的极限强度随着含水率的增加，均存在先增加后减少的趋势，极限强度存在最大值；饲料类别、测试方式和含水率对极限强度有显著影响。采用Design-expert设计响应曲面法，得到目标载荷和保压时间与含粉率之间的响应曲面关系。结果表明，颗粒配合饲料的含粉率与载荷和保压时间之间存在线性关系，目标载荷和保压时间对含粉率均有显著影响，且载荷比保压时间对含粉率的影响更显著。

关键词: 颗粒饲料, 长径比, 含水率, 极限强度, 含粉率, 响应曲面