摘要：The key parameters of the adhesive layer of a reinforcing patch are of great significance and affect the ability to suppress crack propagation in an Al–Li alloy patch-reinforced *** paper proposes a method to determine the key parameters of the adhesive layer of adhesively bonded joints in the Al–Li alloy patch-reinforced structure.A zero-thickness cohesive zone model(CZM)was selected to simulate the adhesive layer’s fracture process,and an orthogonal simulation was designed to compare against the test results.A three-dimensional progressive damage model of an Al–Li alloy patch-reinforced structure with single-lap adhesively bonded joints was *** simulation’s results closely agree with the test results,demonstrating that this method of determining the key parameters is likely *** results also verify the correctness of the cohesive strength and fracture energy,the two key parameters of the cohesive zone *** model can accurately predict the strength and fracture process of adhesively bonded joints,and can be used in research to suppress crack propagation in Al–Li alloy patch-reinforced structures.

摘要：There have been a great demand for a suitable and convenient method in the field of buckling analysis of stiffened ship structures, which is essential to structural safety assessment and is significantly time-consuming. Modeling, buckling behaviors and ultimate strength prediction of stiffened panels were investigated. The modeling specification including nonlinear finite element model and imperfections generation, and post-buckling analysis procedure of stiffened plates were demonstrated. And a software tool using set-based finite element method was developed and executed in the MSC. Marc environment. Different types of stiffen panels of marine structures have been employed to investigate the buckling behavior and assess the validity in the estimation of ultimate strength. A comparison between results of the generally accepted methods, experiments and the software tool developed was demonstrated. It is shown that the software tool can predict the ultimate capacity of stiffened panels with imperfections with a good accuracy.

摘要：从润滑性能引起航天微电机结构温升的角度出发,基于SKF轴承摩擦力矩计算方法,使用***软件,计算了电机在运转和停机状态下各部件的温度分布情况.分析结果显示,由于轴承内圈温度高于端盖,润滑油向端盖扩散,轴承系统润滑性能降低,引起电机转速不稳定.通过在支架端面施加8W的温度补偿,可使轴承内圈温度始终低于轴承端盖温度.仿真和实验证明,施加温度补偿可使微电机的转速稳定性满足设计要求.

摘要：通过正交实验设计,针对中国大型客机专用铝锂合金Al-Li-S4胶接技术中的关键技术——表面阳极化处理进行了参数设计优化。正交设计中以表面处理的参数,即磷酸溶液浓度、处理时间、电源电压、溶液温度作为4个因素,每个因素选择3种位级,进行了9组正交实验,以样品阳极化后的粗糙度作为评判标准,通过优化得出了最佳的阳极化处理方案。对该处理方案和9组实验中直观效果最好的实验方案进行对比,即将经这2种方案处理后的试样进行胶接、固化,测试其剪切强度,结果表明,剪切强度均较高,可以满足使用要求。

摘要：介绍一种新型磁悬浮轴承的工作原理,并且利用动力学和电磁学原理建立磁悬浮轴承系统的数学模型,讨论了刚度阻尼和控制系统的关系,通过此关系确定了常规P ID的控制参数.利用常规P ID的3个参数作为专家P ID控制器的初始参数设计了专家P ID控制器,并在磁悬浮轴承平台上进行了实验.实验结果证明此新型磁悬浮轴承控制系统在专家P ID控制器的作用下能够快速、稳定悬浮,性能良好.

摘要：通过非线性有限元软件marc建立了大型模锻液压机组合垫板结构的三维有限元模型。通过对比分析的方法,研究了在不同厚度、横向偏载和中载和不同的螺栓预紧力下垫板的应力和变形规律。发现这种组合结构中在垫板边缘部分对模压力的分配没有贡献。螺栓在垫板弯曲变形的情况下有滑动趋势。针对这种缺陷给出了相应修改建议,对于指导组合垫板结构设计具有参考意义。

摘要：为揭示多缸并行驱动液压系统多参数耦合作用规律,采用解析法建立了液压机驱动系统动态数学模型。利用变步长Runge-Kutta法探讨了粘性阻尼系数、油液有效弹性模量、管道内径、运动部件质量以及负载刚度等参数对驱动系统动态特性的影响规律。结果表明:粘性阻尼系数增大或减小运动部件质量使系统瞬态振荡幅度减弱;油液有效弹性模量增大或管道内径减小,系统响应速度加快;随着负载刚度增大,主缸稳定压力值增大,开环系统稳态误差增大。液压机在快降过程中不宜采取主动同步控制方式;液压机空载或工件处于塑性变形阶段应重点关注系统稳定性,而工件处于弹性变形阶段时,则应着重提高系统的跟踪精度。研究结果可为液压机驱动系统设计和参数选择提供理论依据。

摘要：应用有限元分析软件***对巨型水压机的主工作缸进行静力分析。以三万吨水压机的主工作缸为研究对象,模拟其在最大工作压力(45MPa)下的应力分布,并与实际测量值对比,验证了有限元模型及分析的准确性。同时分析了在仅改变螺钉位置的情况下,主工作缸各主要应力集中处的应力变化规律。

摘要：主要针对磁悬浮球系统中非接触式位移检测,依据感光器件的光伏效应原理,阐述了非接触式光电传感器的研究与设计,实现了光电信号测量微位移。通过磁悬浮球实验研究表明该传感器的精度(0.01mm)和响应速度(<0.1ms)均达到预期要求,从而给出了一种方便、低成本的位移检测方法。

摘要：随着网络技术迅速发展,校园网的建设已成为各级各类学校实现教育现代化、管理信息自动化不可缺少的基础设施之一。概述了校园网的规划设计方法,对校园网的硬件和软件的设施提出了需求,最后介绍了校园网的安全、故障维护和流量管理的方法,并对校园网的日常管理维护提出了自己的见解。