玉米秸秆-牛粪混料离散元仿真参数标定与试验

Discrete Element Simulation Parameter Calibration and Experiment of Corn Straw-Cow Manure Mixture

摘要:

为了提高玉米秸秆与牛粪混料在离散元压缩成型仿真过程中所需参数的准确性，本文对玉米秸秆-牛粪混料进行参数标定试验，并采用仿真与物理试验相结合的方式对标定参数的准确性进行验证。通过筛选试验得到对混料离散元有显著影响的参数；以堆积角为评价指标，利用Design-Expert软件对3个显著性影响参数进行最陡爬坡试验设计和Box-Behnken试验设计，并应用粒子群优化算法（PSO）进行参数寻优，得到最优参数组合为：玉米秸秆-牛粪滚动摩擦因数0.128、牛粪-牛粪滚动摩擦因数0.320、牛粪-牛粪JKR表面能0.033J/m2；在该参数组合条件下进行仿真试验，结果表明，仿真堆积角与实际堆积角相对误差为1.27%，单轴压缩仿真试验与物理试验的最大压缩位移相对误差为2.97%。研究结果可为玉米秸秆-牛粪混料压缩成型离散元仿真提供依据。

Abstract:

In order to improve the accuracy of parameters required in the discrete element compression moulding simulation process of corn straw and cow manure blends, a parameter calibration test on corn straw-cow manure mixtures was carried out and the accuracy of the calibrated parameters was verified by using a combination of simulation analysis and physical tests. The parameters with significant influence on the discrete elements of the blends were screened out through the screening test;taking the stacking angle as the evaluation index, the Design-Expert software was used to carry out the steepestclimbing experimental design and the Box-Behnken experimental design for the three parameters with significant influence, and the particle swarm optimisation (PSO) algorithm was applied for the parameter optimization, and the optimal parameter combinations were obtained as follows: corn straw-cow manure rolling friction coefficient was 0.128, cow manure-cow manure rolling friction coefficient was 0.320, and cow manure-cow manure JKR surface energy was 0.033J/m2;the simulation test was conducted under the conditions of this parameter combination, and the results showed that the relative error between the simulated stacking angle and the actual stacking angle was 1.27%, and the relative error between the uniaxial compression simulation test and the maximum compression displacement in the physical test was 2.97%. The results can provide a reference for the discrete element simulation of compression moulding of corn straw-cow manure mixture.