共查询到19条相似文献,搜索用时 109 毫秒
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在进行组件级产品振动试验时,传统试验方法存在产品的低阶振动模态激发能力较弱,试验结果重现性差,而采用低频特性优良的电动振动台及其控制仪进行应力加载则可克服RS机的缺陷.本文给出了基于电动振动台的随机振动试验剖面的数学描述,推导出应力量级和试验应力谱参数的解析关系,进而导出便于工程应用的剖面参数计算方法,并讨论了应力剖面的控制.最后在某导弹发射控制盒组件的振动强化试验中进行了应用,验证了该方法的有效性. 相似文献
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本文根据系统振动传递原理,论述了分解子系统振动试验的理论根据、分解子系统的方法、子系统阻抗等效振动试验的各种类型及分解子系统阻抗等效振动试验的优点. 相似文献
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正弦振动试验的目的是在试验室内模拟产品在使用、运输和贮存过程中可能经受到正弦振动时的效应。振动对产品引起变形、弯曲、产生裂纹、断裂,造成部件间的相互撞击等,包括由于振动产生的交变应力超过构件所能承受的弹性和塑性极限应力而造成的破坏,以及由于长时间振动的交变应力造成的累积损伤,使产品发生疲劳损坏。特别是在产品的固有频率与激励频率相同而引起共振导致响应幅值急剧增大时,会更加迅速、更多地发生。 相似文献
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主要通过对产品包装和运输包装测试的介绍,引出振动试验在包装测试中的应用,并对其重要作用、试验方法和参数确定等相关问题进行了探讨。 相似文献
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随着减振降噪及消声技术的发展,水声探测技术逐渐向低频段延伸。相应地,对适用于超低频频段且具有高灵敏度的水听器需求也越来越迫切。该研究基于有限元理论,对4种形式的声压水听器进行了灵敏度对比分析,构建了超低频、高灵敏度声压水听器的系统模型;通过仿真,得到了其前二阶模态,空气及水中的导纳曲线,以及声压接收灵敏度,仿真结果表明,超低频频段内,该研究设计的声压水听器在空气及水中的频响曲线平坦。基于仿真结果进行了样机制作,对所研制的实物样机进行了实验测试,测试结果表明该种声压水听器具有良好的超低频响应特性以及较高的灵敏度。通过对实物样机的测试,验证了其实用性。 相似文献
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常规兵器三综合环境试验技术研究 总被引:1,自引:0,他引:1
对温度-湿度-振动综合试验过程中的环境应力故障分析、试验标准剪裁、试验量值确定、试验设备及试验过程、试验结果评定等问题进行分析论述,分析结果对温度-湿度-振动综合试验设备选型和温度-湿度-振动综合试验具有参考价值。 相似文献
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Anthony S. Donigian Ray K. Linsley 《Journal of the American Water Resources Association》1979,15(1):1-16
ABSTRACT: This paper describes a methodology for the evaluation of water quality plans analogous to procedures used in flood control planning, where flood damage frequency curves provide the basis for determining flood control benefits. The proposed method uses continuous water quality simulation to develop long term information from which water quality frequency curves can be obtained. This frequency information allows the evaluation of the impact of proposed water quality control plans taking into consideration the variable nature of the water resource. Using treatment costs and other economic indicators of water quality, the frequency information can be used to estimate the cost-effectiveness and economic efficiency of alternative plans. The method is demonstrated in a semi-hypothetical environment; real hydrologic and climatic characteristics are assigned to a hypothetical watershed configuration. Alternative management plans are simulated and analyzed for both physical and economic impacts. The advantages of continuous simulation and its use in water quality planning are explored. 相似文献
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Robert B. McKusick J. Herbert Snyder 《Journal of the American Water Resources Association》1972,8(3):431-445
ABSTRACT. Water and related land resource planning has generally been characterized by project evaluation in isolation. Feasible alternatives have been ignored because the economic analysis did not include the interdependence of such subregional and regional variables as factor and product prices and production possibilities. This paper presents an economic framework, consistent with a regional development objective and an efficiency criterion, for proposing and evaluating resource projects. Subregional and regional derived demand curves for water are developed under alternative assumptions of subregional competition, regional market restraints, and yield and price uncertainty. The derivation of water demand curves using the proposed regional framework as compared to sub regional isolation has the desirable properties of (1) a marginal analysis that is more flexible over time is substituted for a static average analysis; (2) range estimates incorporating probabilities are substituted for point estimates; (3) approximations to functional demand curves are substituted for “needs”; and (4) fewer resources are required to meet a regional market restraint. 相似文献
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Magda RouwErnst Worrell 《Resources, Conservation and Recycling》2011,55(4):483-492
Packaging materials are one of the largest contributors to municipal solid waste production. This paper evaluates the material impacts packaging policy in The Netherlands in the period 1986-2007. Five different voluntary agreements were implemented over this period to reduce the environmental impact of packaging. The analysis shows that among the investigated indicators, population statistically is the most robust indicator to estimate the packaging demand. A baseline is developed on the basis of population growth in The Netherlands, and is used as reference to evaluate policy impacts. The policy periods are evaluated on the basis of overall effectiveness compared to the baseline and target achievement. Dutch packaging policies have been effective to reduce the total packaging volume until 1999. After 2000, packaging consumption increased more rapidly than the baseline, suggesting that policy measures have not been effective. The largest increase in packaging recycling rates was achieved during the first policy period. More clear and consistent packaging policy measures and targets could improve the effectiveness of policies. 相似文献
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为了满足消防电子产品提出的正弦振动扫频试验条件,提出了一套在机械振动台上实现定加速度控制方法。通过实际测试及计量,证明该方法定振精度较高,稳定性及可靠性较好。 相似文献