传动角最优的测井仪推靠系统优化设计

通过对微球聚焦测井仪推靠系统主传动机构的运动学、动力学和行程传动角分析.按照实际工况要求,建立了以工作行程内推靠系统主传动机构传动角与期望传动角均方根波动最小为目标的多变量优化设计数学模型.并通过实例计算,对比分析优化前后测井仪推靠系统主传动机构工作行程内传动角的曲线,结果证明,优化效果显著,优化结果改善了推靠系统主传...     

主轴类角度头在变扭器壳体键槽加工中的应用

介绍了角度头的分类,研究了主轴类角度头在变扭器壳体键槽加工中的应用。在应用中,对变扭器壳体键槽尺寸进行了分析,对角度头的类型进行了选择,编制了加工程序,并进行了切削功率核算。在应用中,还需要考虑刀具更换问题。将主轴类角度头应用于变扭器壳体键槽加工中,在实现高效率加工的同时,降低了成本。     

热固性酚醛树脂再生活性细料物性参数标定及应用

为准确评价再生热固性酚醛树脂再生活性细料的机械混合程度,提出了通过休止角合理推测其他参数的思路,并提出了一种粉体休止角测定方法.以休止角作为参照,基于Hertz-Mindlin接触模型与前馈神经网络的预测模型,采用离散元参数标定的方法,对细料离散元物性参数进行标定.采用K-means聚类分析法确定细料离散元参数范围,选...     

Prediction and validation of the profiles of the top and mixed loading surfaces during discharge from multiple-outlet silos

One of the problems for the efficient operation of large industrial silos is that it is difficult to check the volume of the materials that remain inside the silo at any given time. This problem is more pronounced when materials from two or more sources are stored in a multiple-outlet silo, so that the profile of the mixed loading surface, i.e., the interface between materials from different sources, is not visible. To date, no research addressing this problem has been conducted. Therefore, this study proposes a model to predict the profiles of the top and mixed loading surfaces using the simple kinematic theory and considering the effect of the angle of repose on the shape of the top surface. The accuracy of the proposed prediction model was verified by comparing actual profiles of the top and mixed loading surfaces with those predicted by the model when materials were discharged from a multiple-outlet hopper with discharge sequences varying from the left, central, and right outlets. The results showed that the proposed model adequately predicted the profiles with relatively negligible errors.     

夹角和开挖顺序对异形巷道交岔点稳定性的耦合影响

为揭示不同夹角和开挖顺序对矩形与拱形两种不同断面形状的巷道交岔点稳定性的影响,建立5个不同夹角的交岔点数值模型,拟定3种开挖顺序,利用FLAC3D软件进行数值计算分析。结果表明,增大夹角有助于提高交岔点的稳定性,夹角变化时开挖顺序对交岔点稳定性的影响具有统一的变化规律,但在单项指标上各有优劣。选取锐角区水平最大位移、交岔点顶板和底板垂直最大位移、塑性区体积和最大主应力对开挖顺序进行综合评判,确定最佳开挖顺序为方案Ⅱ,即先开挖靠近钝角区的主巷,再开挖支巷,最后开挖靠近锐角区的主巷。研究结果丰富了巷道交岔点稳定性研究成果,可供类似工程参考借鉴。     

Round robin test on angle of repose: DEM simulation results collected from 16 groups around the world

The round robin test (the simultaneous analysis of the same problem) is a method to investigate the variance and sensitivity of results provided by different analysts for a given problem and the reliability of the particular software used by each group participating in the test. A round robin test has been conducted for the traditional numerical method (e.g., finite difference method), but not yet for the discrete element method (DEM). This paper presents the results of the first ever round robin test on the DEM simulation for the angle of repose, involving 16 groups from around the world using different softwares. Within the scope of this round robin test, most groups reported similar simulation results for the angle of repose that differed only by a few degrees from the average of the experimental values, which was initially concealed from participants. There was also good agreement on the degree of variance of the angle of repose. In addition, this paper revealed the recent trends on the interparticle constitutive models and DEM softwares by considering the reports obtained from the participants.     

高速动态测角仪

利用高速线阵CCD和TMS320C62ll定点DSPs处理芯片，实现了对入射光线角度7300次秒的实时测量，对于运动机构的高精度控制有重要的实用价值。     

空间回转轴线交角的测量

本文介绍两种空间回转轴交角的测量方法，并进行了误差分析。