环境荷载联合作用下海上风电结构动力响应分析

为研究海上风电结构在复杂的海洋环境中承受环境荷载(风、波、冰、流)的联合作用时,结构产生的剧烈的动力响应问题。文章以三脚架基础海上风电结构为研究对象,采用ANSYS有限元软件建立其整体模型并进行荷载(风、波、流和风、冰、流)联合作用下的静力校核,通过对环境荷载联合作用下的三脚架基础海上风电结构进行瞬态分析,掌握其动力响应的特性及规律。结果表明:三脚架基础结构的一、二阶自振频率均为0.285Hz,在所选风机允许的频率范围内,可以保证整体结构不会与风机转动发生共振;风荷载在风、波、流荷载联合作用下主导控制结构响应的稳态波动,冰荷载在风、冰、流荷载联合作用下主导控制结构的稳态振动过程;塔筒顶端呈现的位移和加速度响应均远大于三脚架基础顶端;环境荷载联合作用下结构动力响应是环境荷载单独作用下动力响应叠加的结果。     

全方位太阳辐照度测量系统设计

设计一种以DSP为核心的全方位太阳辐照度测量系统,利用安装在云台上的太阳能电池板的转动以获取全方位的太阳辐照度数据。通过对采集到的数据进行分析,既可以测试太阳能电池板在各种安装方式（如平放、斜放和幕墙）下的发电效率,又可对光伏建筑一体化的光伏电站建设方案进行评估,还可在建成之后对光伏电站的发电状态进行管理和监测。     

三叉杆-球笼式万向联轴器传动轴的运动仿真分析

针对三叉杆-球笼式万向联轴器传动轴结构复杂,难以采用传统的图解法、解析法获得其运动规律的问题,采用Pro/E软件,在充分考虑各构件之间的相互约束关系的基础上,对三叉杆-球笼式万向联轴器传动轴整体进行了三维建模,仿真分析了传动轴中关键零件钢球的运动规律,得到了输入轴和中间轴分别在10°、20°和30°夹角下钢球中心的位移、速度和加速度等运动曲线。仿真结果表明,钢球随输入轴的等速回转做近似周期性的简谐运动,并且两个联轴器夹角越大,各运动参数波动的幅度也越大;该仿真结果为合理设计三叉杆-球笼式万向联轴器传动轴,有效解决其在应用中的摩擦、磨损、润滑问题打下了基础。     

带鳞田鱼丸的研制

为了开发青田田鱼加工新产品,结合田鱼鱼鳞柔软可食的特点,进行了带鳞田鱼丸的研制。利用感官评定法、凝胶特性分析、正交实验等方法确定鱼丸的最适生产工艺。结果显示:田鱼糜与杂鱼糜的最适质量比为4:1;正交实验得出最佳鱼丸制作配方为:田鱼糜55%,淀粉15%,色素0.03%,水15%;田鱼鳞片的最佳预处理方式为0.5%醋酸浸泡30min,最适添加量为鱼丸质量的2%~3%。利用本工艺制作的鱼丸,颜色鲜艳,口感爽滑,丰富了市场鱼丸的品种。     

三脚架支承结构的动力修改与再分析

在利用道特征灵敏度分析结果的基础上，对机枪三脚架支承结构作动力修改，获得了使结构固有频度达到预期改善时主要结构参数（敏感参数）的修改量．采用矩阵摄动法进行修改后动态再分析．结果表明，本文所做的动力修改方法可行、结果合理、效果明显．修改结果对改善机枪的动力学特性及改进机枪结构设计具有重要的实际指导意义．     

基于CXD3142R监控系统设计

为了达到远程监控的目的,采用CXD3142R的数字成像系统构建远程监控系统,并做了远程监控的实验。实验表明,该系统通过对视频信息的记录、回放、实时传递的智能管理,实现了预置点设置、定时录像和移动侦测等功能,达到了预期的远程监控的目标。     

7.62mm机枪枪身在模拟弹性架上的动力学分析

对带弹性枪架的机枪系统动力学问题进行了分析研究，构造了机枪系统（射手、机枪、土壤系统）的二自由度动力学模型。作为实例，计算了６７－２式７．６２ｍｍ机枪枪身及其自动机的运动规律，并进行了实验，最后将结果作为对比分析，并对提高机枪研制水平提出了建议。     

Optimal Structural Modifications of a Gun Tripod for Desired Natural Frequencies

Sensitivity analysis and structural modification techniques are used to investigate the structural modifications of a machine gun tripod which suffers from severe vibration during firing due to the resonance. The finite element analysis and modal test techniques are used to determine the natural frequencies of the machine gun. The sensitivities of natural frequencies with respect to the structural parameters of the tripod are obtained by the method of sensitivity analysis, and they can be used as an indication for the structural modification of the tripod so as to shift the natural frequencies effectively. By the structural modification techniques, finally, the optimal structural modifications of the tripod for desired natural frequencies are made to avoid the resonance, and this optimal structural modification is verified by re-analysis of the modified structure and the vibration contrast between original structure and modified structure. The research resulted in a successful structural modification for desired natural frequencies, which can avoid the resonance and thereby greatly improve the shooting precision of the machine gun during firing.     

Seismic evaluation of offshore wind turbine by geotechnical centrifuge test

As offshore wind turbines are now planned to be installed at seismic activity areas around Asia in large numbers, understanding of the seismic behavior of offshore wind turbine has become essential to evade structural hazards due to earthquake. Although the seismic behavior of the structure is largely affected by soil‐foundation‐structure interaction (SFSI), there is only a few experimental data about this subject as conventional offshore wind turbines are mostly located in the area where earthquakes are scarce. Geotechnical centrifuge experiment can provide reliable experimental data for this subject as it can reproduce field stress condition of the soil and simulate earthquake motion in a scaled model test. In this research, three case studies using centrifuge model test were performed to evaluate the seismic behavior of offshore wind turbine during the earthquake and permanent deformation after the earthquake. The results were compared with conventional seismic evaluation methods. Monopile, Monopod, and Tripod foundations were chosen for the experiment. Peak acceleration and rotational displacement of the wind turbine for three cases were evaluated under various intensities of seismic loading applied by centrifuge‐mounted shaking table. Results were compared with conventional evaluation method for design acceleration and conventional rotational displacement criteria suggested in DNV‐OS‐J101.     

三叉式万向节的质疑与改进

三叉式万向节是一种适用于轴角较小的车用新型万向节。作者经过研究,发现它作为一种相交轴间传动用联轴器,在结构上不尽合理,存在有过多的实际约束;因此,作者在理论上证明的同时,提出了原则性的改进意见。