共查询到20条相似文献，搜索用时 31 毫秒
1.
2.
TABESHPOUR M.R. GOLAFSHANI A.A. SEIF M.S. 《浙江大学学报(A卷英文版)》2006,7(8):1305-1317
INTRODUCTION There is obvious demand for oil exploitation in deep water. Increasing water depth will make the environment more severe and so some innovative structures are required for economic production of gas and petroleum in deep water. An engineering idea is the minimization of the structure resistance to en-vironmental loads by making the structure flexible. This structural flexibility causes nonlinearity in the structural stiffness matrix because of large deforma-tions. Wave loadi… 相似文献
3.
针对本田CBR600发动机重心过高问题,重新设计了新的油底壳,降低了59 mm的发动机重心高度,利用ANSYS-VOF模型对两种方案进行对比分析,得出采用“菱形”挡板布置的油底壳具有更好的减晃性能。为避开发动机和地面激励,利用ANSYS-Model模块对新设计的油底壳进行了模态分析,结果表明,油底壳固有频率有效避开了激振频率。装配新设计油底壳的发动机搭载在某学院第三代赛车上,通过近千公里的测试、比赛验证了方案的可靠性。 相似文献
4.
介绍了一种多采样率CIC抽取滤波器.研究了滤波器的原理,重点分析了设计过程中滤波器的误差.在此基础上,用一个滤波器的设计实例验证了滤波器的误差理论,并验证了CIC抽取滤波器通过采样速率变换因子R可降低滤波器的工作频率.结果表明,利用软件控制R可实现多采样率. 相似文献
5.
Giuseppe Carlo Marano 《浙江大学学报(A卷英文版)》2008,9(1):15-25
Based on a multiobjective approach whose objective function （OF） vector collects stochastic reliability performance and structural cost indices, a structural optimization criterion for mechanical systems subject to random vibrations is presented for supporting engineer＇s design. This criterion differs from the most commonly used conventional optimum design criterion for random vibrating structure, which is based on minimizing displacement or acceleration variance of main structure responses, without considering explicitly required performances against failure. The proposed criterion can properly take into account the design-reliability required performances, and it becomes a more efficient support for structural engineering decision making. The multiobjective optimum （MOO） design of a tuned mass damper （TMD） has been developed in a typical seismic design problem, to control structural vibration induced on a multi-storey building structure excited by nonstationary base acceleration random process A numerical example for a three-storey building is developed and a sensitivity analysis is carried out. The results are shown in a useful manner for TMD design decision support. 相似文献
6.
CHEN Li hong 《福建工程学院学报》2001,(Z1)
结合沿江出海口平坦地区的水文地理特点 ,提出雨水管道水力计算须按压力流考虑 ,管道水力计算的设计坡度采用水力坡降 ,管道连接采用管底平接的设计思想与计算方法 相似文献
7.
提出了一种液压系统集成块的设计方法。该方法是将空间六面体的集成块展开到平面上，通过平面图形设计确定集成块上液压油道在空间的位置。该方法便于检查油道之间的相互关系，在实际应用中证明该方法是行之有效的。 相似文献
8.
提出了基于理想情况下以期望输出为设计起点的消色差偏振旋转器的设计思路,并构建了消色差偏振旋转器的优化设计模型,提出了基于遗传算法的宽带偏振旋转器的全局优化设计方法. 相似文献
9.
By an iteration method, the influence of oil film inertia on piston skirt lubrication in a high speed engine is investigated. By alternately solving the Navier-Stocks equations and the Reynolds equation, the new iteration method can trace the variations of velocity field and pressure field with time. Based on this, the mixed-lubrication model suitable for the piston skirt of high engines is proposed. By introducing the inertia coefficient, the new lubrication model includes the inertia term in oil film. The model can be also used to solve for the lubrication performances of a piston skirt in low or medium speed engines and for lubrication problem in general excluding 相似文献
10.
基于PC的主锥选垫实验平台 总被引：1，自引：0，他引：1
介绍了一种以滚动轴承预紧垫片综合测量选配为主的教学实验平台。该平台面向高校机械设计制造及自动化专业课程实验教学,为融合滚动轴承预紧选配、轴承扭矩测量、轴承转速测量、轴承装配等环节而设计。平台采用PC机与数据采集卡作为控制系统,以液压系统作为驱动的模式,增强了整个实验平台的可视性与开放性。 相似文献
11.
利用有限元分析软件Ansys对履带式车辆主车架进行有限元静力分析和模态分析,计算出主车架各部位工作情况下的应力、应变及动态特征,求得在液压马达安装架与车架的纵梁交接处存在最大应力和应变,根据实际情况提出了优化方案。 相似文献
12.
According to the definition of the new hypothetical states which have obvious physical sig-nificance and are termed as no-gravity static and accelerated states, a method for exact computa-tion of the parallel robot's generalized inertia matrix is presented. Based on the matrix theory, the generalized inertia matrix of the parallel robot can be computed on the assumption that the robot is in these new hypothetical states respectively. The approach is demonstrated by the Delta robot as an example. Based on the principle of the virtual work, the inverse dynamics model of the robot is formulized after the kinematics analysis. Finally, a numerical example is given and the element dis-tribution of the Delta robot's inertia matrix in the workspace is studied. The method has computational advantage of numerical accuracy for the Delta robot and can be parallelized easily. 相似文献
13.
传统液压支架产品的设计和应用随着液压支架应用范围的持续扩展,逐渐出现了滞后现象。因此,有必要结合液压支架的现实使用需求,开发一种新型液压支架设计平台。借助蓝光数字矿山地理信息平台,采用VB6.0编程语言实现了液压支架设计系统的参数化与标准化。在液压支架模型建立过程中,现有Delauany三角剖分方法可用于任意多边形的三角剖分。该软件缩短了开发周期,简化了设计流程,降低了设计成本,并提高了设计效率,从而有效增强了产品的市场竞争力。 相似文献
14.
应用Flash技术实现液压与气动元件的动画演示 总被引：2，自引：0，他引：2
本文介绍了运用Flash MX软件的技术,采用补间动画,将工作台的移动、换向阀的换向、阀的移动等动作分散到各层,用箭头表示液体的流动效果,把液压与气动元件的动作、系统的回路从静止不动的图形符号,制作成丰富、生动的Flash动画.并使用Flash播放器播放,或将动画导出在PowerPoint、Word等其它环境下进行播放,利用继续、暂停和方向切换等按钮符号控制播放效果进行动画演示,形象的展现了液压与气动元件和系统的原理和工作特性. 相似文献
15.
具有轮换移动机构的爬壁机器人研究 总被引：1，自引：0，他引：1
李曙生 《泰州职业技术学院学报》2002,2(3):14-17
基于仿生学原理，章提出了一种具有良好越障性能及快速移动的新型爬壁机器人设计方案。中首先简要介绍了该机器人的工作原理，其中包括设计思想和自适应式多真空吸盘。详细描述了转换移动机构的越障特性，并用机器人学的理论对机器人的运动学和动力学进行了分析，并进行了仿真计算，最后得到有关结论。 相似文献
16.
艾红 《中国现代教育装备》2013,(21):20-22
介绍了PROFIBUS现场总线控制系统构成,阐述了基于PROFIBUS现场总线的水箱液位串级控制系统设计与实现、单闭环流量比值控制实现,描述了基于iCAN教学实验开发平台的课程设计。并对现场总线课程设计选题进行了分析。 相似文献
17.
This paper presents the forward displacement analysis of an 8-PSS （prismatic-spherical-spherical） redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting of a PSS joint and a strut with fixed length. A general approximation algorithm is used to solve the problem. To avoid the extraction of root in the approximation process, the forward displacement analysis of the 8-PSS redundant parallel manipulator is transformed into another equivalent problem on the assumption that the strut is extensible while the slider is fixed. The problem is solved by a modified approximation algorithm which predicates that the manipulator will move along a pose vector to reduce the difference between the desired configuration and an instantaneous one, and the best movement should be with minimum norm and least quadratic sum. The characteristic of this modified algorithm is that its convergence domain is larger than that of the general approximation algorithm. Simulation results show that the modelified algorithm is general and can be used for the forward displacement analysis of the redundant parallel manipulator actuated by a revolute joint. 相似文献
18.
To investigate the natural frequencies and towing behaviors of a 3-bucket foundation platform at different drafts, the decay and towing experiments were carried out in a towing tank on a scale of 1:20. The air pressure inside the bucket foundations, the water pressure at the bottom of the bucket foundations, the acceleration of the platform and the towing force were determined in the test process. The time-history curves of the measured parameters were obtained, and the frequency responses of the parameters at different drafts were analyzed by means of fast Fourier transform(FFT). The results showed that the platform natural frequency of heave decreased slightly with the rise of draft. The natural frequencies of roll and pitch are much lower than that of heave, and they increased slightly with the increase of draft. When towing in the following sea, the maximum acceleration of surge, sway and heave has downward trends with the increase of draft, but the change range decreased gradually with the increase of draft. When the draft is 5.0 m(the ratio of draft to bucket height is 0.56), the towing dynamic responses achieve the maximum, which is not conducive to the towing of the platform. When the draft is 6.0 m(the ratio of draft to bucket height is 0.67), the towing dynamic responses are the most stable. 相似文献
19.
分析了基于在线考试平台的试卷分析的意义,采用教育测量原理给出了试卷、试题的分析指标,提出了基于在线考试平台的试卷分析方法,给出了试卷分析系统的数据库设计,实现了试卷分析报告的自动生成。 相似文献
20.
基于FPGA的信号发生器的设计 总被引：4，自引：2，他引：2
贺敬凯 《深圳信息职业技术学院学报》2008,6(2):63-66
简要介绍了直接数字频率合成（DDS）的组成及其工作原理,给出了基于Ahera公司的FPGA实现多波形信号发生器的设计过程和电路结构。设计在QuartusII软件中完成,并给出了仿真波形。该设计用FPGA实现,因此有许多优点。比如：在不修改硬件电路的情况下频率可调,波形可以选择正弦、三角等多种波形,且电路结构简单、扩展性好,具有频率范围宽、频率分辨率高、相位连续、切换速度快等优点。 相似文献