Results 71 to 80 of about 13,790 (168)
Gaoya dianqi, 2021 针对一二次融合配电开关设备运行过程中实时数据标准化度、采集准确度和处理效率低,导致决策水平融合性差以及故障诊断误差大突出等问题,文中提出了基于不同信息类型的分类、识别与融合决策方法,形成了标准化的数据源。在此基础上开发了基于决策层的融合算法、一二次融合开关设备实时运行数据准确采集与高效处理技术和BP神经网络故障模型的故障快速诊断系统,通过大幅提高实时运行数据采集精度和处理速度,为用户赢得提前处置故障信息的宝贵时间,当运行中的一二次融合配电开关设备发生故障时能够及时向用户发出预警及对故障隔离。经试验验证 ...
韩筛根 +3 more
doaj
, 1982 传统的寿命估算方法是名义应力法,这种方法根据构件的名义应力历程、构件的S-N曲线和累积损伤理论估算寿命。这种方法需要做构件的S-N曲线,而且估算的结果常常很不精确。近年来国外发展起一种新的寿命估算方法,这种方法根据构件关键部位的弹塑性分析,将名义应力历程转化为关键部位的局部应力-应变历程,根据局部应力-应变历程和材料的疲劳特性及累积损伤理论进行裂纹形成寿命的估算,称之为局部应力-应变法 ...
伍义生
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Study on failure characteristics and control of roof separation with weak interlayer of deep gob-side entry driving [PDF]
Roof with weak interlayer has significant influence on the stability of deep gob-side entry driving, to effectively control the separation of roof with weak interlayer in deep gob-side entry driving under high deviatoric stress, based on the mechanical ...
Bowen WU +5 more
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FATIGUE RELIABILITY ASSESSMENT of MULTI-LOADING SUSPENSION BRIDGES BASED ON SHMS [PDF]
, 2014 考虑到火车、汽车与风荷载的长期作用以及多荷载的随机性,评估大跨多荷载桥梁的疲劳可靠度是一项富有挑战的任务。该研究基于健康监测系统提出了大跨多荷载悬索桥的疲劳可靠度分析框架,并应用到香港青马大桥。首先,定义了疲劳可靠度的极限状态函数,基于监测数据建立火车、汽车与风荷载的概率模型。基于概率模型和蒙特卡洛模拟方法,利用疲劳关键位置上多荷载的每日随机应力响应,估计每日应力幅M次方之和的概率分布。假设交通保持不变,可确定在给定时段内应力幅M次方之和的概率分布。最终得到桥梁不同疲劳关键位置不同时间点的疲劳失效概率 ...
陈志为
core
Analytical solution of predicting rib spalling depth of fully-mechanized coal working face based on tri-linear strain softening model [PDF]
In order to predict rib spalling depth in fully-mechanized mining faces, taking the coal wall as the research object, the coal wall is regarded as a tri-linear strain softening material. Then the direct roof and main roof are taken as macro roof, and the
Chunhui ZHANG +3 more
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Gaoya dianqi, 2022 随着电力物联网的高速发展，庞大数量的分布式传感器的供电问题成为了亟待解决的技术难题。摩擦纳米发电机作为一种高效且低成本的新型供能技术，在自驱动传感领域具有极大的应用前景。文中提出并研制了一种面向电力物联网应用环境下的宽风速摩擦纳米发电机自驱动系统，创新地引入了同心双转轴的结构设计，使其在宽风速范围下能够有效收集风能并保证优异的输出性能。实验阶段搭建了基于风力涡轮机的风力测试平台，测试了不同风速下摩擦纳米发电机的基本电气性能和负载特性。最后构建并演示了所设计的摩擦纳米发电机自驱动系统 ...
冯运 +6 more
doaj
Jianzhu Gangjiegou Jinzhan型钢混凝土组合结构中采用超高性能混凝土（ultra-high performance concrete，UHPC）可以提高承载能力、减小截面尺寸，同时改善其因密集配置箍筋和剪力件而导致的施工复杂等问题。目前型钢UHPC组合梁有限元仿真研究主要集中在受弯性能参数化定性分析，忽略了型钢与UHPC间的黏结滑移，缺少对其界面黏结性能和组合效应的评估，对受拉区UHPC的受力性能也缺乏深度讨论。对型钢UHPC组合梁开展基于Abaqus的受弯性能有限元仿真分析，对UHPC强度、型钢强度 ...
沈德建 +4 more
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Gaoya dianqi, 2012 为了探寻电子设备中的单元电路在电磁脉冲激励下的响应规律以及响应输出与输入脉冲干扰之间的关系,笔者选用两种不同型号的运算放大器集成芯片组成的仪表放大电路进行了脉冲注入实验。根据采集的实验数据,分析了脉宽、幅值等因素对响应输出的影响。通过对比发现:一定功能的电路,在同一类但不同参数的脉冲激励下,响应有所不同,且与各参数有一定的联系。根据基于人工神经网络的系统辨识理论,建立了能量耦合模型。经过自验证,其拟合度能够达到88.4%,且具有较好地泛化能力,能够定性地对电路做出响应预测。
刘卫超, 魏明, 樊高辉, 吴启蒙
doaj
Failure depths of stope floors under dynamic loading induced by roof breaking [PDF]
ObjectiveAccurately assessing the failure depths of stope floors is crucial for assessing floor water inrush risks. Conventional theoretical models for calculating the failure depths generally merely consider static loads from the support pressure and ...
Bo XU +5 more
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Main control factors of rock burst and its disaster evolution mechanism [PDF]
With the gradual transfer of shallow coal mining to deep coal mining in China, the rock burst disasters are becoming an increasingly serious problem. In the process of rock burst mechanism cognition to rock burst prevention engineering, the primary task ...
Deyuan FAN +6 more
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