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1.
中子管是一种用途广泛的关键部件,然而目前国产中子管的可靠性水平与国外相比还有一定差距,难以满足各行业的使用需求。本文分析了中子管的主要故障模式,采用模糊综合评判和层次分析法对中子管故障进行了多级模糊综合评判,并对中子管故障风险进行了评估。结果表明,中子管总体故障风险水平中等,故障风险前3位的部件为靶、氘氚储存器和加速极,在设计和使用中应重点关注靶释放氦气,靶膜氧化,氘氚储存器吸气剂局部破损,绝缘瓷管破损,加速极离子加速、聚焦不稳定等故障。  相似文献   
2.
Predictive maintenance is one of the important technical means to guarantee and improve the normal industrial production. The existing bottlenecks for popularization and application are analyzed. In order to solve these problems, a cooperative awareness and interconnection framework across multiple organizations for total factors that affect prediction maintenance decision-making is discussed. Initially, the structure and operation mechanism of this framework are proposed. It is designed to support the sharing of data, knowledge and resources. As a key supporting technology, the digital twin is also integrated into it to improve the accuracy of fault diagnosis and prediction and support making a maintenance plan with higher accuracy and reliability. Then, under this framework, an integrated mathematical programming model is established with considering the parameter uncertainty and an NSGA-II hybrid algorithm is utilized to solve it. Moreover, an adjustment strategy for a maintenance plan is discussed in response to the dynamic characteristics of the actual maintenance environment. Finally, a case, prediction maintenance decision-making for bearings in grinding rolls of the large vertical mill, is studied. Analysis results verify the advantage of the integrated solving mechanism based on the proposed framework. The framework and integrated decision-making approach can guide the implementation of predictive maintenance with higher accuracy and reliability for industrial enterprises.  相似文献   
3.

一种用于空间光学载荷隔振的被动式隔振器设计与测试

杨剑锋1,2,3,黄创绵1,2,4,王远航1,3,4,李锴1,2,4

(1.工业和信息化部电子第五研究所,广州 510610;

2. 广东省电子信息产品可靠性与环境工程技术中心,广州 510610;

3. 广东省电子信息产品可靠性技术重点实验室,广州510610;

4. 广州电子信息产品可靠性与环境工程重点实验室,广州510610)

创新点说明:

本文提出了一种构型新颖的用于空间光学载荷隔振的隔振器,该隔振器具有结构简单、环境适应性强、隔振效果好等优点。通过对其静态特性进行分析,推导得到隔振器的等效刚度模型,考虑到粘弹性阻尼材料其阻尼系数随激励频率和环境温度变化的特点,给出一种基于复刚度模型的分析方法。最后,设计、加工出了一套隔振系统的原理研究,并对其静态性能及隔振性能进行了测试试验。试验结果表明:本文提出的用于粘弹性阻尼材料动力学分析的分析方法有效,计算值与测试结果具有较好的一致性,设计的隔振器可以有效降低传递给光学载荷的振动。

研究目的:

设计一种适用于空间光学载荷在轨隔振的隔振器,并给出其隔振性能的分析方法。

研究方法:

复刚度理论、有限单元法;

试验仪器:HF-10型数显式拉亚测试机,气浮平台,力锤,频谱分析仪。

结果:

静刚度分析值与测试值的最误差大4.21%,最小误差为0.02%,模态分析计算值与测试结果几乎一致,隔振性能分析低频段分析值与测试结果吻合度较好,但高频段出现一定偏差。

结论:

本文设计的隔振器隔振性能较好,能适应不同空间光学载荷的隔振需求,文中提出的用于粘弹性阻尼材料动力学分析的分析方法准确、有效,适用于被动式粘弹性材料隔振器的隔振性能分析。

关键词:隔振器;粘弹性材料; 空间光学载荷

  相似文献   
4.
余热排出系统管道发现的热疲劳裂纹问题关系到压水堆的安全。本文基于开源有限元软件Code_Aster,采用Lagoda-Macha-Sakane模型预测了余热排出系统管道材料304L不锈钢的疲劳寿命,并根据预测结果提出了改进的Lagoda-Macha-Sakane模型。采用改进的Lagoda-Macha-Sakane模型对余热排出系统管道的热疲劳寿命进行了预测,结果表明预测热疲劳寿命与试验热疲劳寿命吻合。  相似文献   
5.
决定信息安全评估结果是否科学有效的前提和基础是选择正确的风险评估方法,因此如何选择就成为关键。该文将模糊综合评价方法和数据包络(DEA)方法相结合,提出一种筛选评估方法的数学模型,用于评价风险评估方法的有效性。该方法充分考虑评价指标的客观性,从工程的角度综合计算进行风险评估活动的投入与产出,从定量的角度考察风险评估的评估效果,该方法具有良好的可操作性,为风险评估人员筛选更有效、科学、合理的评估方法提供一个具有实用价值的数学工具。  相似文献   
6.
Big data is one of the most important resources for the promotion of smart customisation. With access to data from multiple sources, manufacturers can provide on-demand and customised products. However, existing research of smart customisation has focused on data generated from the physical world, not virtual models. As physical data is constrained by what has already occurred, it is limited in the identification of new areas to improve customer satisfaction. A new technology called digital twin aims to achieve this integration of physical and virtual entities. Incorporation of digital twin into the paradigm of existing data-driven smart customisation will make the process more responsive, adaptable and predictive. This paper presents a new framework of data-driven smart customisation augmented by digital twin. The new framework aims to facilitate improved collaboration of all stakeholders in the customisation process. A case study of the elevator industry illustrates the efficacy of the proposed framework.  相似文献   
7.
压水堆核电站余热排出系统冷热水混合区管道发现的热疲劳问题影响核反应堆的安全。本文通过一种采用单轴疲劳试验数据拟合疲劳寿命曲线,进而用于预测多轴疲劳寿命的分析方法,基于文献中的疲劳试验数据,对Dang Van模型、Matake模型和Fatemi-Socie模型进行了余热排出系统冷热水混合区管道材料304L不锈钢疲劳寿命预测结果的对比研究。基于余热排出系统冷热水混合区管道的三维简化有限元模型,分别应用Dang Van模型、Matake模型和Fatemi-Socie模型对管道热疲劳寿命进行了预测,并与试验结果进行了对比验证。研究结果表明,基于应变(含平均应力修正)的Fatemi-Socie模型比较适用于304L不锈钢的疲劳分析,其热疲劳寿命预测结果相对Dang Van模型、Matake模型较合理。  相似文献   
8.
The study aims at evaluation of the steady-state heat dissipation capability of a high-density through silicon via (TSV)-based three-dimensional (3D) IC packaging technology (briefly termed 3D TSV IC packaging) designed for CMOS image sensing under natural convection through finite element analysis (FEA) and thermal experiments. To enhance modeling and computational efficiency, an effective approach based on FEA incorporating a 3D unit-cell model is proposed for macroscopically and thermally simulating the heterogeneous TSV chips. The developed effective thermal conductivities are compared against those obtained from a rule-of-mixture technique. In addition, the proposed numerical models are validated by comparison with two experiments. Besides, the uncertainties in the input chip power from the specific power supply and in the measured chip junction temperature by the thermal test die are evaluated. Finally, a design guideline for improved thermal performance is provided through parametric thermal study.  相似文献   
9.
To investigate the degradation of the touchpad usability by surface wear, the touchpad with new, worn, plastics and paper surfaces are examined in terms of performance and frictional response. It is found that the friction coefficient of the surface affect the usability. It is concluded that the major factors controlling the friction was surface roughness. It is also found that friction coefficient is affected by the difficulty of the task. The reasons for this is the human tendency to be cautious, he/she try to reduce the load to be precise. Then the load dependence of friction coefficient results in high friction. The other reason is mental sweating, which will be increased when the task is difficult.  相似文献   
10.
甚长波红外波段富含大气湿度、CO2含量及云层结构和温度轮廓等大量信息,是大气遥感的重要组成部分。设计了一种3232甚长波红外焦平面阵列,采用在ZnCdTe衬底上液相外延生长的As掺杂p型材料上进行B+离子注入形成光敏元,通过铟柱倒焊技术和带有改进型背景抑制结构的读出电路互联,制成截止波长达到14 m的焦平面器件。该红外焦平面器件像元面积为60 m60 m,工作温度在50 K温度下。测试结果显示:读出电路性能良好,焦平面黑体响应率达到1。35107V/W,峰值探测率为2。571010 cmHz1/2/W,响应率非均匀性约为45%,盲元率小于12%。  相似文献   
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