建筑结构抗震特性有限元分析评估

随着计算机性能的不断提高,采用有限元软件对结构抗震性能进行评估成为一种趋势。介绍了建筑结构抗震性能评估方法,指出采用静力弹塑性分析方法可对建筑结构破坏形式、塑性铰位置进行计算,并对结构的性能点进行分析。介绍了常用建筑结构抗震性能有限元软件及其主要原理,对采用有限元软件进行建筑结构抗震性能评估的相关研究进行了总结与分析。设计了第1~第3层层高5m、第4~第20层层高3m、共20层的典型型钢-混凝土结构,采用核心筒模式,应用ANSYS有限元分析软件得到了建筑位移,结果表明,该结构能够满足我国高层建筑规范"小震不坏、中震可修、大震不倒"的要求,为高层建筑结构设计提供了参考及有限元实践实例。     

基于有限元法的核工程液压系统抗震研究

核工程液压系统属于抗震Ⅰ类机械设备,在极限安全地震震动(SL-2)引起的载荷作用下,必须保持其功能性。根据核安全法规要求必须对抗震Ⅰ类机械设备进行抗震性能鉴定。本文根据液压系统结构及工况特性,采用有限元法,对核工程液压系统有限元模型进行模态分析和谱分析,并通过计算,评估了核工程液压系统在地震条件下的抗震性能,为核级设备抗震研究提供了一定参考。     

基于时间历程响应的核电站环吊抗震分析

针对地震反应谱分析法的不足,以某三代核电站环吊为研究对象,建立了环吊抗震计算模型,研究其在SSE地震发生过程中的抗震性能.运用ANSYS对环节进行地震时程响应分析,计算评估在SSE地震中吊车结构受力、变形等在地震载荷作用下的响应情况.抗震计算结果也表明,对核电站大吨位环吊进行地震时程分析,实施抗震性能设计校核,是非常重...     

核级主给水控制阀性能评估技术研究

针对核二级主给水控制阀抗震性能评估的要求,基于ASME规范和Femap+NX Nastran有限元平台,研究核阀虚拟性能评估技术。首先,针对直立式控制阀门的结构特点,提出了直立式控制阀执行机构力学模型,给出了结构风险评估及改进方法。然后,对于某型号控制阀进行仿真分析,通过实验数据和仿真数据的对比,验证了有限元分析技术的有效性;最后,对所设计的核二级主给水控制阀在地震载荷及设计组合载荷作用下的抗震性能进行分析。典型部位处的应力仿真结果与经验公式计算结果误差小于5%。仿真结果表明所设计阀门整体自振频率大于33 Hz,具有良好的抗震性能,并且各工况下阀门承受应力在许用应力范围内,满足设计要求。     

基于ANSYS Workbench高压电阻箱式结构的抗震分析

利用有限元分析软件ANSYS Workbench作为仿真平台,采用振型分解反应谱法对高压电阻箱式结构进行抗震分析,得到电阻箱式结构的位移、速度、加速度动力响应及整体结构的等效应力响应,评估结构的抗震性能。     

基于ANSYS Workbench通信机柜的抗震分析

利用ANSYS Workbench对通信机柜进行了模态分析,并用振型反应谱法对机柜结构进行抗震分析,从而得出机柜结构在一定频率范围内地震振动下的响应,评估了机柜结构的抗震性能,对于通信机柜的抗震设计有一定的参考价值。     

桥梁动载监测仪的时频分析编程实现

随着运输行业中车辆载重性能的提高、运行速度的提升以及车辆的增多,对桥梁的破坏日趋严重,因此对桥梁的动载性能进行实时监测已成为桥梁维护工作的重要任务之一。及时、快捷地掌握桥梁动载性能对判断桥梁的综合状况、辨识桥梁故障的有无、保证运输的安全畅通有着重要意义。通过VB编制程序对利用加速度传感器采集的桥梁振动信号进行时域和频域的分析,为桥梁的实时监测和评估提供了重要依据。     

1E级智能温度变送器的抗震试验研究

首先介绍了1E级温度变送器整体的硬件设计、软件设计。然后对1E级温度变送器进行抗震试验,并具体阐述了抗震试验的评估方法及试验步骤。最后,抗震鉴定试验表明,此温度变送器在试验中及试验后结构完整并运行功能完好,设计符合核安全级抗震Ⅰ类的抗震要求。     

某核电站柴油发电机组抗震分析

柴油发电机组属于抗震Ⅰ类设备,根据核电安全法规必须对抗震Ⅰ类设备进行抗震性能鉴定。利用有限元分析软件ABAQUS建立机组整体有限元模型,以机组所在厂房标高的楼层反应谱为地震输入利用反应谱分析法采用CQC振型组合结合SSRS地震方向组合并考虑自重和柴油机不平衡力矩作用对机组进行抗震分析,根据ASME规范中B级和D级使用准则评估机组抗震性能,结果表明忽略公共底座应力集中的情况各机组部件抗震性能良好。采用修正的等效静力法对机组部分连接螺栓进行可靠性分析,结果表明在等效地震加速度作用下螺栓强度满足ASME规范并且预紧力设计合理。     

钢筋混凝土核心筒结构抗震性能分析和设计方法研究

城镇化发展进程不断加快,建筑工程逐渐趋向于高层化发展。为保障建筑结构安全稳固,需要重点关注钢筋混凝土核心筒结构抗震性能,配合使用适宜的建筑设计方案。本文以钢管混凝土框架中的钢筋混凝土核心筒结构抗震性能概念为切入点,提出核心筒结构抗震性能设计参数,通过使用静力弹塑性与动力弹塑性分析方式,优化钢筋混凝土核心筒结构抗震性能设计方案,以供参考。     

起重机械金属结构振动与故障诊断的研究

在桥梁、高层建筑的结构安全测试和旋转机械的振动故障分析等应用中,振动测试技术已形成了一套完整的体系,该体系包括测试原理及方法、特征信号的处理与提取、故障诊断和状态识别。在起重机械金属结构服役安全评估与评价方面,结合大量的现场振动测试数据结果发现,金属结构的疲劳失效与结构的振动响应密切相关,故此对将振动研究与故障诊断应用于起重机械金属结构服役安全评估上的可行性展开了探讨,并提出振动失效机理研究、振动故障诊断是目前急需要解决的难题。     

基于能量算子梯度邻域特征提取的核电应急柴油发电机组故障诊断方法

气门间隙故障作为应急柴油发电机组(EDG)的典型故障,容易导致性能下降、机械故障等,传统人工拆盖检查气门间隙的方式费时费力.利用Teager能量算子的瞬态振动识别能力,结合振动冲击能量变化规律,提出了一种基于能量算子梯度邻域的振动冲击始点自适应精确提取的EDG气门间隙故障在线诊断方法,该方法的故障识别参考阈值为EDG设...     

振动图像结合CNN的轴承振动信号分析方法研究

本文以强背景噪声下振动信号特征提取和建模分析为研究目标,提出将振动信号转换为振动图像的信号变换方法,以深沟球轴承故障诊断振动信号和轴承质量等级评估振动信号为实验数据集,基于振动图像的卷积神经网络模型（VI-CNN）,并采用正确识别率（CRR）作为模型精度的评价指标。实验结果表明:对于轴承故障诊断和质量等级评估的定性判别,采用VI-CNN对比其他建模方法正确识别率分别为100%和98.16%,模型有更好的稳健性。     

Design of a wireless measurement system based on WSNs for large bridges

The structural vibration detection for large bridges is critical. A wireless measurement system based on Wireless Sensor Networks (WSNs) for large bridges was developed in this paper. The overall architecture of the wireless system is introduced; the design of wireless nodes and the principle of the central station are given in detail. Experiments are conducted in the laboratory and the Nanjing IV Yangtze River Bridge to verify the performance of the designed system. Experimental results show that the performances of the designed system are improved in the transmission distance. The system anti-jamming ability and data transmission packet loss rate are also improved compared to traditional wireless sensor systems. Meanwhile, with the external sensing interfaces, the system has a superior performance in characteristics of high sensitivity and ultra low frequency. It can easily and quickly carry out structural vibration detection for a large bridge in its construction, future operation, and maintenance periods with strong practicality and high application value.     

A scheme for an internet-based checking method of machine-tools with variant CNC architecture

This paper proposes an Internet-based checking technique for machine-tools with variant Computerized Numerical Controller (CNC). According to its architecture, CNC is classified into one of two types: Closed Architecture Controller (CAC), which is the conventional CNC, or Open Architecture Controller (OAC), which is a recently introduced PC-based controller. Since CAC has a closed architecture, it is dependent on CNC vender specification. Because of this, it has been very difficult for users to implement application programs in the CNC domain. Recently, the conventional CNC of machine-tools has been replaced by a PC-based open architecture CNC. However, now many conventional CAC machines are being operated together with OAC machines in inadequately equipped shop floors. For Internet-based checking for variant CNC machines with CAC and OAC, a suitable systematic environment is necessary. Through this research, for the global management of variant CNC machines both a CAC and an OAC in the manufacturing system, a suitable environment for Internet-based checking of variant CNC machines was designed, and the checking methods for CAC and OAC machines were compared. The results of this research may serve as a base model for global monitoring and remote control in an integrated manufacturing system with variant CNC machines. Checking points defined in this research are classified into two categories: structured point and operational point. The former includes the vibration of bearing, temperature of spindle unit, and other points of periodical management, while the latter includes oil checking, clamp locking/ unlocking, and machining on/off status.     

载货汽车驾驶室车身噪声控制策略

针对载货汽车驾驶室本身,结合其结构特点,从结构传播噪声和空气传播噪声入手,阐述了驾驶室车身噪声性能的评价方法和噪声控制的主要策略,综合采取车身隔振、壁板减振、阻尼控制、隔声处理、吸声处理、密封控制等多种措施进行降噪处理。     

检具随机误差的验收评定方法

介绍了四种常用的检具随机误差验收评定方法，并分析了各种评定方法的特点及适用性。     

Identification modale sous excitation ambiante : Application à la surveillance des ponts

Vibration measurements on bridges are not recent and many studies were carried out in the past by the LCPC and many French or foreign agencies or companies. What is new today, it is the increase of the number of dynamic tests carried out on bridges for a better assessment of their structural behaviour. The prime objective in a dynamic assessment is the determination – or identification – of the modal characteristics. That includes natural frequencies, damping ratios and mode shapes. The use of tests under ambient vibration is increasingly popular today because they make it possible to measure the structural response in service. The increase in the data acquisition system capacity and data storage also largely supported the development of tests under ambient vibration. The excitation can be induced by wind, pedestrians or vehicles traffic or any other live loads. In this case, identification methods which do not require measurement of the excitation source must be used. After pointing out the objectives and the stakes of bridge dynamic testing, this paper highlights some of these methods and provides some practical applications.     

桥梁结构损伤的振动模态检测

首先介绍了桥梁结构损伤检测的振动模态方法的原理及其４ 个要素。总结了用模态参数（固有频率、阻尼比及位移振型）进行损伤检测评估的困难,进而阐述应变模态测量的原理及其用于桥梁结构损伤检测时,相对于位移模态的优势。由于应变模态方法应用于实桥检测受到传统应变测量手段的制约,本文最后提出了一种通过相邻点振动位移的测量,推估桥梁在动载作用下的应力状态,进行实桥损伤检测的途径,并推荐一种新型低频高灵敏度传感器作为位移测量用传感器。     

集装箱正面吊运起重机试验体系研究

基于GB/T 16905-1997《集装箱正面吊运起重机试验方法》,阐述了集装箱正面吊运起重机试验项目体系,确立了集装箱正面吊运起重机试验评价体系,归纳了其试验方法及注意事项.为全面考核集装箱正面吊运起重机是否达到设计要求的主要性能指标提供决策依据.