Authors

Abstract

The Plackett-Burman factorial experiment was carried out by Design-Expert for 10 related factors. The simulation calibration experiment with JKR contact model was performed based on discrete element method (DEM) with mixed biomass sawdust as the research object. Taken the Box-Behnken experiment together with the steepest climbing test scheme, the parameters of the multi-response indicators were calibrated as follows: the Poisson's ratio of mixed biomass sawdust is 0.30; the density is 399.22 kg·m-3; the recovery coefficient between sawdust particles is 0.47; the rolling friction coefficient between sawdust particles is 0.39 and the parameter of surface energy density between sawdust particles (JKR) is 0.29 J/m². The comparative verification experiments indicate that the relative error of the repose angle is 3.41% and the relative error of the stress-time response curve is less than 6.36%. These results verify the reliability of the calibration method and provide a theoretical reference for the study of the constitutive characteristics of biomass materials and the densification mechanism.

Abstract in Chinese

以混杂生物质木屑为研究对象，基于EDEM离散元原理进行接触模型为JKR的仿真标定试验，利用Design-Expert针对10种相关因素进行Plackett-Burman析因试验，结合最陡爬坡试验方案，根据Box-Behnken试验，完成响应指标为堆积角、成型压制力、应力松弛时长的参数标定，其结果为：混杂木屑的泊松比0.30，密度399.22 kg·m-3，木屑颗粒间的恢复系数0.47，木屑颗粒间的滚动摩擦系数0.39，木屑颗粒间的JKR表面能密度0.29 J/m²。通过对比验证试验可知，堆积角的相对误差为3.41%，应力-时间响应曲线的相对误差小于6.36%，验证了该标定方法的可靠性，为生物质本构特性及致密成型机理的研究提供了理论参考。