载重绳索参数激励横向振动的减振策略

论述了一种抑制载重绳索参数激励横向振动的简便方法. 假设绳索底端的质量受到一个垂直简谐激励并忽略载重绳索高阶振型的影响, 载重绳索的运动方程可以用一个带有立方非线性项的Mathieu方程来描述. 根据Mathieu方程的有关理论, 在载重绳索系统中, 当索端质量垂直振动的频率接近绳索横向振动固有频率2倍时, 一旦索端质量垂直振动的幅度超过某个临界数值时, 绳索将产生参数共振. 为了避免这种现象, 建议在索端质量上加装一个减振器以削减索端质量的垂直振动, 进而抑制绳索的横向振动. 实验验证了该减振方案的有效性.     

The revival of thermal utilization from the Sun: interfacial solar vapor generation

Since solar energy is the ultimate energy resource and a significant amount of global energy utilization goes through heat, there have been persistent efforts for centuries to develop devices and systems for solar–thermal conversion. Most recently, interfacial solar vapor generation, as an emerging concept of solar–thermal conversion, has gained significant attention for its great potentials in various fields such as desalination, sterilization, catalysis, etc. With the advances of rationally designed materials and structures and photon and thermal management at the nanoscale, interfacial solar vapor generation has demonstrated both thermodynamic and kinetical advantages over conventional strategies. In this review, we aim to illustrate the definition, mechanism and figures of merit of interfacial solar vapor generation, and to summarize the development progress of relevant materials and applications, as well as to provide a prospective view of the future.     

一种机动车前轮悬架的设计及应用

该文介绍一种新型机动车前轮悬架,它由主、副减振器以及减振弹簧组成,其中减振弹簧由三个螺旋弹簧并联组成,在承受不同载荷时,减振弹簧刚度值随之变化。在主减振器与副减振器间存在较小夹角,并随载荷不同而发生变化,有利于改善了阻尼系数。这种结构提高驾驶时的舒适性,特别适合在单前轮机动车上使用。     

不同减震器对弓箭系统减震效果的动态测试

为了借助动态测试方法来研究弓箭系统，特别是研究弓的减震问题，采用美国产HOYT牌T／D-3反曲弓，选用ESTON和BEITER两种减震器，以四川省射箭队的4名优秀运动员为测试对象进行测试。运动员根据这一反馈信息选用BEITER减震器后，通过短暂的适应过程，在2002年全国射箭奥林匹克项目锦标赛上获得个人赛第一的优异成绩。结果表明，通过动态测试这种方法对弓箭系统的研究可以为运动员选弓和调弓以及选择不同的减震器提供一些有价值的参数，提高训练效率和射箭成绩。     

汽车传动轴减振器静动刚度测试分析

论述了在用MTS810材料试验机进行静动态性能测试的原理及方法,并对三种汽车传动轴减振器试件分别进行静刚度、动刚度特性测试。测试结果表明,这种方法简单、有效。试验结果为汽车传动轴减振器的改进提供了参考依据。     

Parametric design of an electrorheological shock absorber with the mixed-mode

1. Introduction As is known, the function of a suspension system is to support an entire vehicle at axles so as to improve ride comfort by vibration absorption. It also provides handling stability in steering and acceleration as well as braking. However, the solution of the design contradiction between ride comfort and handling stability can抰 be achieved by passive suspension system elements. Some active suspension systems have been developed in order to handle the compromise, but they requi…     

关于谐激励下无阻尼多自由度系统的振动

给出了一般初值条件下无阻尼自由度振系对简谐激励的响应公式，作为特例讨论了无阻尼动力吸振器，结果表明无阻尼动力吸报器并不能完全消除主系统的振动。     

A microgap surge absorber fabricated using conventional semiconductor technology

A new type microgap surge absorber fabricated by only semiconductor technique has in it a special structure silicon chip which forms microgaps for gas discharge with electrodes, and has advantages such as small size, low cost, suitability for mass production besides the desirable characteristics that common microgap surge absorbers have. Applications of this absorber in communication facilities are discussed.     

可变阻尼对汽车悬架系统振动性能影响分析

通过建立1/4悬架系统的理论数模,分析阻尼系数影响系统的幅频特性.在不同的振动频率范围内,阻尼的相应变化将改善悬架系统的输出性能.     

An Energy Absorber with Force Modificator

Thin-walled tubes are extensively applied in engineering, especially in vehicle structures to resist axial or traversal impact loads, for their excellent energy absorbing capacity. However, in the axial deformation mode, the force history has an extremely high peak force which may bring not only fatal injury to occupants but also damage to structures, cargo and environment. Aiming to develop energy absorbers with impact-force modificator, square metal tube with force modificator is investigated which can monitor the force-deformation history of the tube. A small device is designed to serve as an impact-force modificator, which introduces desired imperfections to the square tube just before the impact happens between the impactor and the tube, so as to reduce the peak force. Prototypes with various governing parameters were manufactured and tested both quasi-statically and dynamically to study the effects of these parameters on the characteristics of energy absorption. The results show that the force modificator can achieve the desired reduction of the peak force well whilst remaining the specific energy absorption capacity of the original square tube. With future improvements, it could be applied to vehicles or roadside safety hardware to mitigate the consequences produced by traffic accidents.