弹簧质量对振子振动周期影响的实验研究

通过对有弹簧质量弹簧振子的振动实验,分析研究弹簧振子振动周期与弹簧质量的关系,并提出"轻质弹簧"实验中的振子质量与弹簧质量关系.     

如何计算有质量弹簧的形变量

在高中物理阶段,所处理的弹簧问题,都是将弹簧理想化为轻质弹簧,即没有质.如果将两个大小不等的F作用于轻弹簧的两端,根据牛顿第二定律F=ma,轻弹簧将会产生无穷大的加速度,导致问题无法研究.因此大多高中题目中都强调是轻弹簧,弹簧各处张力相等,两端受的的拉力大小时刻相等,弹簧伸长量根据胡克定律△x=F/k,其中F是弹簧一端受力的大小.如果是有质量的弹簧则不同,对于有质量的弹簧两端的拉力可以随便取,一旦弹簧两端拉力不同时,伸长量又是多少呢?     

非轻质弹簧串联系统能量分析

在弹簧质量不能忽略的情况下,讨论了串联弹簧振子系统动能和弹性势能表达式,结果表明：串联弹簧的动能不仅与两弹簧自身的质量m1、m2有关,还与各弹簧的劲度系数k1、k2密切相关;串联弹簧的弹性势能只由各弹簧劲度系数和串联弹簧的总伸长量决定。     

低温制冷机用柔性弹簧的研究进展及分析

阐述了柔性弹簧的结构类型和评价指标,归纳和总结了国内外柔性弹簧的研究现状和发展趋势。针对低温制冷机的大冷量和长寿命需求,提出了我国研究发展柔性弹簧的一些关键技术,完善柔性弹簧的综合性能评价标准,加强柔性弹簧的动态性能分析和弹簧组件研究,开发适应大冷量低温制冷机的间隙密封用柔性弹簧组件,实现柔性弹簧的自主设计。     

多弹簧串联系统能量计算

在弹簧质量不能忽略的情况下,推导了n个弹簧串联系统的动能和弹性势能具体表达式,结果表明:n个串联弹簧系统的动能与每个弹簧自身质量、劲度系数密切相关;系统的弹性势能由n个串联弹簧的等效劲度系数和串联弹簧的总伸长量决定.     

弹簧的质心

依据圆柱形弹簧的劲度系数公式和胡克定律,导出了形变前后有重量的弹簧上同一点相对于弹簧固定端的距离关系式,给出了弹簧非均匀形变的数学表述,讨论了弹簧的质量分布和质心位置问题.     

平行型片弹簧机构的类型及特性

1.根据产生平行运动的受力的情形,提出了无轴向力平行型片弹簧机构形式。2.无轴向力平行型片弹簧机构在空间综合受力下片弹簧端部的变形和应力计算。3.单片弹簧的类型及平行型片弹簧机构的组合类型。4.平行型片弹簧机构的设计原则要点。     

弹簧等效质量和劲度系数示波器测量法

介绍了利用圆柱状弹簧作为电路电感元件,把弹簧振动信息转变为电信号,通过数字存储示波器的扫描模式显示,记录弹簧在一段时间内的振动过程,从而可对振动系统的振动周期进行比较直观的测量,进而测出弹簧等效质量、弹簧劲度系数.     

弹簧串、并联略谈

如图1所示，已知弹簧A的劲度系数为k1，弹簧B的劲度系数为k2，如果把两弹簧串联使用，在弹簧末端挂一个重为G的物体，弹簧A，B所受的拉力均为G，设弹簧A的伸长量为△x1，弹簧B的伸长量△x2，则有     

滑动摩擦力作用下弹簧振子的振动

对在粗糙水平面上作振动的弹簧振子进行研究,探讨该弹簧振子最后停止的位置,估算了弹簧振子的振动总次数,得出弹簧振子的相轨迹.     

考虑弹簧质量的振子精确解

给出了考虑弹簧质量时弹簧振子系统频率的精确解，指出了近似解的实质是假设弹簧的位移模式为线性模式，而其实解的位移模式为正弦曲线；算例的结果显示，通常情况下，精确解的一阶位移模式与线性模式非常接近，因此近似解具有相当的精度．     

Analysis of a damped pneumatic spring

The complex dynamic stiffness of a damped spring is determined. The damping is produced by transient pressure feedback from an auxiliary tank connected by a capillary to the spring cylinder. From the complex stiffness, the damping and stiffness are determined as functions of excitation frequency. The behavior of a compound spring, consisting of a damped pneumatic spring in parallel with a stiffer linear spring, is also examined. The analysis shows that the damping loss factor depends only on the tank/cylinder volume ratio, and that the capillary dimensions affect only the frequency at which maximum damping occurs. The compound spring is shown to have a maximum loss factor which quickly reaches an asymptotic value as the tank/cylinder volume ratio increases. From this presentation a clearer understanding of the behavior of a damped air spring, and a better sense of how design parameters affect the component's characteristics are obtained.     

螺旋弹簧变形的一种推导

用自制的演示仪器,容易说明弹簧的形变主要是由金属丝的扭转引起的,借助于量纲分析及螺旋弹簧变形机理的二维模型,直接推导出螺旋弹簧的变形公式与劲度系数。     

Seasonal variation on radon emission from soil and water

Radon is being measured continuously in spring water and soil-gas at Badshahi Thaul Campus, Tehri Garhwal in Himalayan region by using radon Emanometer since December 2002. An effort was made to correlate the variance of radon concentrations in spring water and soil-gas with meteorological parameters at the same location. The main meteorological parameters that affect the radon emanation from host material is surrounding temperature, barometric pressure, wind velocity, rain fall and water level of the spring. The correlation coefficient between radon concentration in spring water and different atmospheric parameters was computed. The correlation coefficient between radon concentration in spring water and the maximum atmospheric temperature was 0.3, while it was 0.4 for minimum atmospheric temperature at the monitoring site. The correlation coefficient for radon concentration in spring water with minimum and maximum relative humidity was 0.4. Spring water radon concentration was found positively correlated (0.6) with water discharge rate of the spring. A weak correlation (0.09) was observed between the radon concentration in spring water and rain fall during the measurement period. As temperature of near surface soil increases, the radon emanation coefficient from the soil surface also increases. The possible effects due to global warming and other climatic changes on environment radiation level were also discussed in detail.      

Finite element mapping for spring network representations of the mechanics of solids

We present a general finite element mapping procedure for defining spring network representations of solid mechanics. The procedure is rigorous and equally suitable for setting regular and unstructured spring network models of generally anisotropic solids. We use the procedure to define close-packed triangular and simple cubic lattice spring models of isotropic 2D and 3D elastic media, respectively. We extend the study to heterogeneous solids and show that the mapped spring network approach constitutes an appealing route for incorporating subelement level constitutive equations.     

弹簧振子实验不确定度的分析研究

采用静力伸长法和振动周期法测量并计算弹簧振子的劲度系数,通过分析不确定度,比较了用静伸长法求弹簧劲度系数中逐差法和用最小二乘法作Excel直线拟合这两种数据处理方法的精确性差异,并通过计算得出测量弹簧劲度系数时静伸长精确度高于振动法的结论。实验结果具有一定的理论意义,并对于改进弹簧振子实验过程有重要的指导作用。     

Dynamic optimization design of a cylindrical helical spring

In this paper, a numerical method to model the dynamic behavior of an isotropic helical spring is coupled with optimization algorithms to construct a dynamic optimization method based not only on mechanical and geometrical objective functions and constraints; but also on dynamic ones. In the proposed dynamic optimization problem, four geometric parameters are chosen as design variables (wire diameter, middle helix diameter, active coils numbers and spring pitch). In addition of mechanical and geometrical constraints, dynamic ones related to natural frequencies of the helical spring are added. Two objective functions are chosen to be optimized: the spring mass and its natural frequencies. This method is then applied to the case of circular cross section helical spring, and then optimization results are presented and discussed.