风力机叶片气动载荷的优化研究

为了研究垂直轴风力机的叶片气动性能,利用流固耦合法模拟了垂直轴风力机在实际工况下的气动载荷分析,模拟结果表明,由于翼型后部较薄,受到的变形应力最大。为了避免因叶片变形而引起风力机整体气动性能下降,提出了通过加大翼型后部厚度的方案来提高叶片的强度,并通过数值模拟对改进后的翼型做了气动性能分析,得出了适当的增加翼型后部厚度,并不会对翼型气动性能造成太大的影响,验证了此方案的有效性。这些研究结论为今后垂直轴风力机的设计制造提供了一定的参考依据。     

压装机装卸料机械手的研制

介绍了某品牌汽车组件装配线上压装机装卸料机械手,其主要功能是在两台压装机和物料自动输送线之间实现物料的自动安装、卸下和传递,并保证准确定位,且能装卸多种型号组件以实现生产线的多品种加工。阐述了机械手的功能和工作循环,介绍了针阀式缓冲活塞动力油缸、手臂、手爪等主要结构及特点。该机械手抓取和传动精度高,大大提高了生产效率。     

Effects of loading methods on rabbit welfare and meat quality

The effects of different loading methods on the welfare, carcass characteristics and meat quality traits of hybrid commercial rabbits were investigated. 384 male rabbits, 82 days old, were transported from the farm to the slaughterhouse. At the farm, 192 rabbits were loaded onto the truck smoothly (S) and 192 rabbits were loaded roughly (R). The S loading method consisted of carefully placing each rabbit into the transport crates. In the R method, the loading was hurriedly and carelessly executed by the transport operator, throwing each animal into the crates fixed on the truck.     

D433柴油机连杆螺栓的疲劳性能及其检验指标

着重研究了Ｄ４３３柴油机连杆螺栓的疲劳性能。通过两个欠螺栓的轴向疲劳试验，运用数理统计方法，获得该螺栓的疲劳极限，并对试验结果做出分析讨论，从而Ｄ４３３柴油机连杆螺栓疲劳极限的检验指标为平均载荷（Ｐｍ）３０．０ｋＮ、交变载荷（Ｂ１０）１０．０ｋＮ，以保证螺栓的质量和生产。     

一种袋装产品在线装车机械手设计

针对目前袋装产品在线装车主要靠人工完成,工人劳动强度大、装车效率低、环境恶劣等问题,设计了一种袋装产品在线装车机械手。给出了机械手的总体结构、主要功能和工作原理;重点设计了装有4个缓冲弹簧的双层落袋机构、可以补偿落料装置与货车车帮之间距离误差的摆动机构和落料门宽窄变换机构,减小了袋装产品下落时的冲击力,保证了袋装物料的完整性,实现了车厢空间的最大化利用,可以适应不同规格的袋装产品。对压缩弹簧和关键轴进行受力分析,从实用性和可靠性方面验证了结构设计的合理性。     

电液疲劳试验系统加载策略研究

为更好地复现实际工程中物体所受的各种复杂载荷,提出一种基于相位控制的双激振器电液疲劳试验系统:应用流体动力学和系统动力学理论建立激振器与疲劳试验系统数学模型,非线性分析激振器激励-响应特性,拟定疲劳试验系统加载策略;最后搭建试验平台,验证理论分析的准确性及加载策略的可行性。研究结果表明:实测激振器输出力波形与仿真分析结果基本一致,所拟的3种加载模式可达预期目标,即疲劳试验系统能输出不同频率和极值的拉-压交变力、交变力矩和交变力偶矩满足试验需要。     

Untersuchung des Einflusses der Beanspruchungsgeschwindigkeit auf das Deformations‐ und Bruchverhalten von Weizenkörnern

Compression tests of deformation and fracture behavior of wheat grains were carried out at different loading rates that varied from 0.02 to 0.11 mm s^–1. The contact model originally developed for the spherical particles was adapted to describe the deformation and fracture behavior of elliptical wheat grains. The distributions of basic fracture parameters of wheat grains such as fracture force, fracture strength, fracture energy, and fracture displacement were fitted with normal distribution function.     

Rock salt dilatancy boundary from combined acoustic emission and triaxial compression tests

This paper presents an experimental investigation of rock salt dilatancy boundary based on combined acoustic emission and triaxial compression tests carried out on the rock salt samples from the Asse Salt Mine, Germany. The experimental results were evaluated to determine the dilatancy boundary under specified stress, stress loading rate and pore pressure. Pore volume changes caused by deviatoric stresses were measured during triaxial compression tests. The dilatancy boundary was then determined from the maximum compression on a stress–strain curve which separates the compression and dilatancy regions. Variations in acoustic emissions that occur during microcrack development under triaxial compression were recorded with ten sensors mounted on the outer surface of the cylindrical samples. A spontaneous increase observed in the cumulative number of acoustic events is consistent with the dilatancy boundary determined from the minimum pore volume. It is confirmed that the dilatancy boundary depends on both stress loading rate and pore pressure. The dilatancy boundary slightly decreases with increasing the loading rate, but increases with increasing the minor normal stress. High pore pressures accelerate the dilatancy. A Biot coefficient of 0.25 for Asse rock salt was determined from the dilatancy boundary. An analysis of two-dimensional (2D) fractal dimensions determined for several samples shows that the samples with smaller dimensions have slightly higher dilatancy boundaries. The dilatancy boundary values of Asse rock salt are lower than those reported for crystalline rocks, although both rock types show similar dilatancy behaviour.     

DSP56362的双引导装载方法研究与实现

简要介绍了MOTOROLA公司的24位定点数字信号处理器DSP56362的并行引导过程和特点。并结合实际，提出了一种双引导模式，给出了具体的实现方法。通过这种双引导模式．巧妙地达到了系统的要求。另外，介绍了采用DSP软件编程来实现FLASH擦除和读写方法。     

沥青混合料疲劳性能影响因素的研究

主要就材料性质、环境温度和荷载条件对沥青混合料疲劳性能的影响进行了较为系统的研究。在这基础上提出了预测沥青混合料疲劳寿命的公式。同时还列出了沥青混合料弯拉强度和劲度的有关试验结果。