共查询到20条相似文献，搜索用时 484 毫秒
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船舶板架结构除了受到自身重力和设备重力作用外,还受到激振力的作用。应用大型有限元软件ANSYS软件对部分船体板架在受设备激振力和不受设备激振力两种情况进行计算,并就计算结果进行对比分析。结果显示,往往被我们忽视的激振力对船舶板架结构强度的影响不容忽视。 相似文献
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以Ф800衬里热风阀阀体为对象,针对热风阀阀体结构特点及工艺要求,运用有限元技术对热风阀阀体结构进行模态分析,研究了阀体在其固有频率下激振力和动应力间的关系,为选择振动时效中所施加激振力的频率提供了依据．通过振动时效,有效降低了阀体焊接残余内应力． 相似文献
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低应变基桩检测中传感器及激振技术 总被引：1，自引：0，他引：1
王东青 《辽宁科技学院学报》2001,3(2):46-49
基桩低应变检测中传感器的选择及安装技术、激振技术直接则到测试准确与否。本文根据波动理论及从事桩检测的实践经验，重点探讨低应变基桩检测中传感器技术及激振技术。 相似文献
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在轴承滚子裂纹缺陷无损检测中,对滚子采用敲击激振方法,分析敲击所发出的声音的频谱谱形特征,揭示因裂纹使滚子受激所发出的声音的音频特征的变化规律. 相似文献
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《实验室研究与探索》2020,(4):59-62
设计了海洋立管涡激振动实验。首先设计单立管涡激振动实验,通过实验,学生可掌握应变片半桥设计的基本知识,波流联合水槽及数据采集仪的工作原理和使用方法,学会立管涡激振动的测试方法,并且对涡激振动的理论知识进行巩固和强化。在此基础上拓展进行立管群涡激振动实验及涡激振动抑制实验,分析立管间距以及不同抑振装置对涡激振动的影响,增强了学生应用所学知识发现问题、分析问题和解决问题的实践创新能力,从而达到提高教学质量的目的。 相似文献
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《实验室研究与探索》2017,(3):44-47
以桥梁模态测试研究为工程背景,为解决桥梁模型模态测试中常规激振装置存在的不足,研制了一种小型惯性式激振器。该激振装置主要由步进电机、驱动器、控制器、齿轮传动部件、一对偏心质量块及底座组成。对某大跨度悬索桥模型进行激振,通过动力放大系数峰值处激振频率确定共振时模态频率,并与ANSYS有限元模型计算、锤击自由振动实验结果对比,证明了该激振器在桥梁模型模态测试中的适用性。该激振器具有质量轻、体积小、激振频率精准可控的特点,除在模型模态测试中的应用,还为实验教学及实际桥梁的激振提供了新的思路和方法。 相似文献
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王兆香 《中国科教创新导刊》2008,(5):129-129
历史教学的方法多种多样,本文主要从质疑激趣、电教激趣、竞赛激趣、图片激趣、情感激趣、角色激趣、故事激趣、成语激趣这＂八大＂激趣方法来研究如何激发学生学习历史的兴趣。 相似文献
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本文围绕现代素质教育课堂教育教学效果升值的普遍问题,探究了课堂教学升值激趣的六种方法:图画激趣;语言激趣;实物激趣;情景激趣;活动激趣;情绪激趣。 相似文献
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采用激振方法,以声卡做为数据采集卡,应用MATLAB专用工具箱构建轴承滚子无损检测数据采集与处理系统,给出MATLAB环境中的程序设计和实现过程,并用实例证明该系统的有效性和实用性. 相似文献
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This paper proposes a new numerical simulation method for analyzing the parametric vibration of stay cables based on the theory of nonlinear dynamic response of structures under the asynchronous support excitation. The effects of important parameters related to parametric vibration of cables, i.e., characteristics of structure, excitation frequency, excitation amplitude, damping effect of the air and the viscous damping coefficient of the cables, were investigated by using the proposed method for the cables with significant length difference as examples. The analysis results show that nonlinear finite element method is a powerful technique in analyzing the parametric vibration of cables, the behavior of parametric vibration of the two cables with different Irvine parameters has similar properties, the amplitudes of parametric vibration of cables are related to the frequency and amplitude of harmonic support excitations and the effect of distributed viscous damping on parametric vibration of the cables is very small. 相似文献
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Stay cables, the primary load carrying components of cable-stayed bridges (CSBs), are characterised by high flexibility which increases with the span of the bridge. This makes stay cables vulnerable to local vibrations which may have significant effects on the dynamic responses of long-span CSBs. Hence, it is essential to account for these effects in the assessment of the dynamics CSBs. In this paper, the dynamic responses of CSBs under vehicular loads are studied using the finite element method (FEM), while the local vibration of stay cables is analyzed using the substructure method. A case study of a cable-stayed steel bridge with a center span of 448 m demonstrates that stay cables undergo large displacements in the primary mode of the whole bridge although, in general, a cable’s local vibrations are not obvious. The road surface roughness has significant effects on the interaction force between the deck and vehicle but little effect on the global response of the bridge. Load impact factors of the main girder and tower are small, and the impact factors of the tension of cables are larger than those of the displacements of girders and towers. 相似文献
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以某双塔单索面人行钢斜拉桥为对象,采用Midas Civil建立全桥空间杆系有限元模型,进行恒载、活载和承载能力极限状态作用下结构受力性能分析,同时开展该桥的动力特性分析。研究表明:对于该异形斜拉桥,活载引起的主梁和主塔弯矩效应较恒载作用下的结果更加显著;承载能力极限状态作用下,该桥主梁、主塔、斜拉索等主要承重构件的最大应力均小于材料容许应力,满足规范要求;动力特性分析结果表明主梁面内刚度和主塔面外刚度较小,此外遮阳棚的局部振动在高阶振型中所占比例较大,在地震作用下可能发生破坏;该桥的一阶竖向自振频率为1.92 Hz,不满足现行规范要求,建议采取有效的减振措施来控制人致振动响应。 相似文献
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ZHANG Xin-jun YING Lei-dong 《浙江大学学报(A卷英文版)》2007,8(5):693-698
To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable’s cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge, its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable’s cross-sectional area should be deter-mined by the principle of equivalent axial stiffness. 相似文献
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The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables'sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper. 相似文献
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The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables' sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper. 相似文献
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李文 《辽宁科技学院学报》2021,23(1):14-16,47
电梯是现代高层建筑必不可少的组成部分,而作为电梯最重要的零部件,曳引钢丝绳在使用过程中经常会出现断丝,断股和油污过重等情况,如不及时处理,容易引发各种电梯的安全事故,造成较大的人员和财产损伤。传统的检测方法往往不能及时地发现曳引钢丝绳的缺陷,文章通过集成了微处理器、A/D、I/O、存储器、图像处理软件、模式识别软件的机器视觉检测系统来对电梯曳引钢丝绳进行检测,能够有效地避免这一问题,提高工作效率和存在问题的检测率,从而有效地预防电梯事故的发生。 相似文献
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同相大截面并联电缆敷设对其电流分布的研究 总被引：1，自引：0，他引：1
介绍了某变电站内6.6kV单芯交联聚乙烯绝缘500mm2电缆同相两根并联的敷设和运行情况,通过ANSOFT软件模拟计算,分析出其载流量不平衡的主要原因是同相并联电缆的外感值不相同。通过研究分析,建议在同相多根并联的高压大截面电缆线路中采用上下两层水平布置、正＂品＂型和水平对称排列布置的敷设方式。 相似文献
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