基于DEM与MFBD双向耦合生物质成型模具疲劳寿命分析

Fatigue Life Analysis of Biomass Molding Die Based on Bidirectional Coupling of DEM and MFBD

根据环模成型机的实际攫取工况,考虑环模与压辊和物料间存在大量接触和碰撞的非线性力学行为,采用FFlex法建立柔性体动力学模型;建立环模成型机的DEM-MFBD双向耦合的模拟仿真模型,使结果更加接近实际情况。采用正交试验,分析环模转速、模辊间隙、颗粒粒径对颗粒所受压力的影响。结果表明:各因素对试验指标的影响按大小次序排列应当是最小模辊间隙、颗粒粒径、环模转速。分析不同参数对环模最大扭矩的影响,结果表明:环模转速在5~6 rad/s时,环模所受最大扭矩随着环模的转速增加而增加,而环模转速增加到6 rad/s后,环模所受最大扭矩随着环模转速的增加而减小;在颗粒粒径为2~2.4 mm时,随着颗粒粒径的增加,环模最大扭矩也不断增大。将EDEM-RecurDyn耦合得到的数据结果导入到Durability模块进行疲劳寿命分析,结果显示,环模比压辊更容易出现疲劳破坏。

According to the actual picking conditions of the ring die forming machine,considering the non-linear mechanical behavior of a large amount of contact and collision between the ring die and the pressure roller and the material,the FFlex method was used to establish the dynamic model of the flexible body,and the ring die forming machine was established.The DEM-MFBD bidirectional coupling simulation model of the ring die forming machine was established,which can make the results closer to the actual situation.Using orthogonal test,the particles pressure with the three factors of ring die speed,die roll gap and particle size were analyzed.The results show that the influence of each factor on the test index should be arranged in the order of the smallest die roll gap,particle size and ring die speed.The influence of the maximum torque of the ring die was analyzed with different parameters.The results show that when the speed of the ring die is 5~6 rad/s,the maximum torque of the ring die increases with the increase of the ring die speed,and when the ring die speed increases to 6 rad/s,the maximum torque on the ring die decreases with the increase of the ring die speed.When the particle size is 2~2.4 mm,as the particle size increases,the maximum torque of the ring die also increases.The data results obtained by the EDEM-RecurDyn coupling were imported into the Durability module for fatigue life analysis.The results show that the ring die is more likely to cause fatigue damage than the pressure roller.