井下振动环境分析与模拟

智能导钻井下工具及仪器在钻进过程中产生复杂的振动,剧烈或长时间振动会造成井下仪器的电路故障与钻具机械疲劳破坏,引发钻井事故,增加钻井成本.为了验证井下仪器的振动环境适应性与可靠性,需要开展破坏机理、井下工况数据采集与分析、测试与试验的体系化研究,在实验室充分发现仪器潜在的故障,不断迭代升级,提升仪器可靠性.本文通过自主研制的井下振动冲击记录仪器在实钻井中采集真实的振动环境数据,对数据进行处理分析后,制定了三个方向的振动试验条件;定制研制了国内首台专门用于井下仪器测试的双台并激振动试验系统,研究了基于双台振动设备的并激振动试验与测试方法,实现了实验室条件下真实模拟井下振动环境,构建的系统化井下振动试验平台有效支撑了井下工具及仪器的高质量研发.     

单层结构远程协同拟动力试验平台开发

基于网络通讯平台NetSLab,采用Visual Basic语言开发了一个标准化的开放式单层结构远程协同拟动力试验平台NetSLab-SDOF,它由控制中心、真实试验机、虚拟试验机和远程观察器4个模块组成,并通过互联网传输试验控制信号和反馈数据。该平台可以使不同的结构实验室联合进行结构拟动力试验,同时还提供远程用户同步观察试验并获取试验数据的功能。通过桥梁结构的真实拟动力试验及数值模拟试验和网络速度测试,验证了NetSLab-SDOF试验平台的有效性。     

桩基静载试验与高应变对比分析

桩基承载力对桩基抗震性能有很大影响。通过对大量的桩基静载荷试验和同一根桩上的高应变的对比研究，总结了高应变测试极限承载力的准确性与可靠性，分析了引起高应变测试结果误差的原因，提出了消除高应变测试误差的一些方法和注意事项。     

基于OpenSees的钢骨混凝土受弯构件非线性有限元分析

分别考虑了钢材和混凝土的非线性性能,在开源软件OpenSees的平台上,采用纤维截面模型对钢骨混凝土受弯构件进行非线性有限元分析,并将计算结果与相关的试验结果进行了对比分析。分析结果表明:本文采用的纤维模型得到的计算结果与试验结果比较吻合,验证了在OpenSees的平台上,选择合理的本构及计算参数的纤维模型分析钢骨混凝土梁的可靠性。     

采用位移外环控制的拟动力试验方法及验证

拟动力试验是一种重要的结构抗震试验方法。在该类试验中,试件出力大,连接件和支座往往产生滑移与弹性变形,导致试件实际位移与期望位移存在较大偏差,降低试验数据的精度和可靠性。位移外环控制,是在作动器控制回路之外直接以试件位移为控制变量的控制回路,是解决该问题的有效方法。本文阐述了PI(即比例-积分)位移外环控制的原理,分析了在非实时平台实现该控制的延迟不确定问题,详细介绍了在混合试验平台软件Hy Test中的实现架构。采用混合试验平台软件Hy Test及该外环控制方法,完成了阶跃命令试验、单自由度结构拟动力试验和6自由度结构拟动力试验模拟,研究表明该方法稳定可靠,能大幅提高位移控制精度。     

砂土液化大变形本构模型及在ABAQUS软件上的实现

基于Yang和E lgam al等人提出的砂土液化大变形本构模型,对该模型的建立过程进行了详细的推导,基于新的嵌套屈服面硬化规则,对原有模型的硬化规则的不连续性做了改进,把该本构模型扩展应用到三维液化大变形的数值分析中,实现了基于ABAQUS大型商用软件计算平台上砂土液化大变形的计算子程序的开发,基于该计算平台和开发的本构模型,对动三轴试验体系中砂土试样的液化过程进行了数值试验分析,给出了试验过程中试样的竖向动位移、整体竖向应力应变关系滞回曲线和动孔压时程曲线的数值计算结果。文中初步验证了该模型在ABAQUS上开发的子程序的可靠性和数值计算模型的可行性,模型的可靠性及其子程序的稳定性还需通过试验结果和数值计算结果的对比分析与进一步验证。     

土样剪切波速超声测试装置与方法研究

本文介绍了自行设计的土样剪切波速超声测试装置与测试方法，与扭剪三轴仪相结合，测试了多组干砂试样的剪切波速，检验了量测系统的可靠性，探讨了试件的边界条件及震相识别等问题，试验测得的干砂在不同固结压力下的剪切波速，与Hardin公式吻合良好，表明所研制的测试装置及测试方法是可行的。     

测震专业软件评估平台在地震行业中的应用1

本文简要介绍了测震软件评估平台的基本架构和功能,通过具体测试实例阐述了评估平台的应用,为地震行业专用软件的测试提供了一个比测运行的软件支撑平台.通过对被测软件进行合理、有效的测试,评价了被测试专业软件在数据汇集、数据交换、实时处理、交互处理、地震编目、数据管理与服务等方面的功能和性能指标,为进一步完善和改进测震专业软件提供了相应的实验依据,为地震行业专用软件的质量保证起到积极作用.     

手持式钻孔应变仪井下传感器现场检测装置的设计和应用

介绍了在WIN CE控制平台下设计的一种钻孔应变仪井下传感器现场检测装置。设计采用了基于32位ARM工控触屏板以及嵌入式Windows CE操作系统作为软硬件平台,集成了485通信接口和多通道高精度模拟信号的数据采集单元,实现对钻孔应变仪井下传感器(应变传感器、气压、水位、水温传感器)部分的控制、调零、故障检测等功能,完成了基于触控界面的人机交互界面设计,优化了检测步骤,提高工作效率。实际测试和台站应用表明,本装置具有方便,轻巧,操作简单等特点,并具有较高的可靠性和稳定性,可满足地震台站对钻孔应变仪井下传感器的实际检测要求。     

PHC管桩单桩振动台试验与数值模拟对比分析

利用振动台对PHC管桩进行单桩承台模型试验;同时将土体PHC管桩-上部结构视为共同工作整体,建立三维有限元模型,再以ABAQUS软件为计算平台,对单桩试验工况下的地震反应进行数值模拟计算,并将试验结果与数值模拟计算结果进行对比分析。结果表明：数值模拟和振动台模型试验基本吻合,两者得到的地震反应影响体现出相似的规律性,印证了模型试验的可靠性和数值模型的合理性。     

地震力作用下海洋平台的可靠性研究

本文分析了在地震力作用下海洋平台的受力情况,文中运用概率论原理,建立了海洋平台在地震力作用下的可靠性分析方法。     

Hybrid platform for vibration control of high‐tech equipment in buildings subject to ground motion. Part 2: analysis

The experimental results of using a hybrid platform to mitigate vibration of a batch of high‐tech equipment installed in a building subject to nearby traffic‐induced ground motion have been presented and discussed in the companion paper. Based on the identified dynamic properties of both the building and the platform, this paper first establishes an analytical model for hybrid control of the building‐platform system subject to ground motion in terms of the absolute co‐ordinate to facilitate the absolute velocity feedback control strategy used in the experiment. The traffic‐induced ground motion used in the experiment is then employed as input to the analytical model to compute the dynamic response of the building‐platform system. The computed results are compared with the measured results, and the comparison is found to be satisfactory. Based on the verified analytical model, coupling effects between the building and platform are then investigated. A parametric study is finally conducted to further assess the performance of both passive and hybrid platforms at microvibration level. The analytical study shows that the dynamic interaction between the building and platform should be taken into consideration. The hybrid control is effective in reducing both velocity response and drift of the platform/high‐tech equipment at microvibration level with reasonable control force. Copyright © 2003 John Wiley & Sons, Ltd.     

Hydrodynamic constraints and storm wave characteristics on a sub‐horizontal shore platform

Few studies of wave processes on shore platforms have addressed the hydrodynamic thresholds that control wave transformation and energy dissipation, especially under storm conditions. We present results of a field experiment conducted during a storm on a sub‐horizontal shore platform on the east coast of Auckland, New Zealand. Small (<0.5 m) locally generated waves typically occur at the field site, whereas during the experiment the offshore wave height reached 2.3 m. Our results illustrate the important control that platform morphology has on wave characteristics. At the seaward edge of the platform a scarp abruptly descends beneath low tide level. Wave height immediately seaward of the platform was controlled by the incident conditions, but near the cliff toe wave height on the platform was independent of incident conditions. Results show that a depth threshold at the seaward platform edge > 2.5 times the gravity wave height (0.05–0.33 Hz) is necessary for waves to propagate onto the platform without breaking. On the platform surface the wave height is a direct function of water depth, with limiting maximum wave height to water depth ratios of 0.55 and 0.78 at the centre of the platform and cliff toe, respectively. A relative ‘platform edge submergence’ (water depth/water height ratio) threshold of 1.1 is identified, below which infragravity (<0.05 Hz) wave energy dominates the platform energy spectra, and above which gravity waves are dominant. Infragravity wave height transformation across the platform is governed by the relative platform edge submergence. Finally, the paper describes the first observations of wave setup on a shore platform. During the peak of the storm, wave setup on the platform at low tide (0.21 m) is consistent with measurements from planar sandy beaches, but at higher tidal stages the ratio between incident wave height and maximum setup was lower than expected. Copyright © 2014 John Wiley & Sons, Ltd.     

基于工业CT力学实验平台的建立及应用

将工业CT与数字体图像相关法相结合测量物体内部三维变形及应变已发展成为一种新的实验力学方法。本文介绍基于工业CT,自行研制的加载装置和数字体图像相关法(DVC)建立起的力学实验平台,该平台包括基本原理模块、数字虚拟实验模块、原位加载扫描实验模块、变形计算模块和结果输出模块,可以实现单轴压缩、三点弯曲、四点弯曲、点加载及拉伸实验试件内部三维变形场的测量。针对岩石材料与复合材料介绍该平台的应用。      

An experiment with joint mapping of the vertical velocity and its horizontal gradient in the study of recent tectonic movements

An experiment is described dealing with the detailed mapping of the vertical velocity V of recent crustal movements in the central Danubian riverside region of the Moesian platform in Northern Bulgaria. The error in V being significant here, the problem of statistical control on the reliability of the initial data and results of such studies is investigated; this question is also relevant for other platform regions in Eastern and Central Europe. With the aim of assessing the significance of a movement, the sampling distribution of V is used. The problem is reduced to a checking of a standard statistical hypothesis and to a probabilistic characterization of V. In order to estimate the statistical significance of the relative velocity δV between neighbouring benchmarks, the distribution of the module G of the horizontal gradient of V is studied. An agreement between the sampling distribution obtained and the theoretical Weibull distribution is established. A sufficiently high probability P>86% is determined for the significance of δV in this region and an optimal interval of the isobases is suggested. The experiment itself embraces three variant solutions: independent mapping of V, independent mapping of G, and mapping of V with respect to G. The analysis and comparison of the results obtained demonstrate the high efficiency of the third solution.     

奉节钻孔应变前兆异常机理分析——区域应力场应力传递的结果

奉节钻孔应变前兆异常对应震例较远，前兆异常机理不明确。结合其他观测数据和历史背景资料，对比分析该异常的可信度及观测物理意义，并进一步利用有限元模拟方法分析其前兆异常机理。结果显示：奉节钻孔应变的趋势变化与附近的其他观测资料较吻合，能记录到区域应力场的变化信息。数值模拟分析认为该台位于扬子地台四川台坳东缘，扬子地台基底较硬，具有很好的应力传递性；地台边缘岩性破碎较软，受力易变形，对块体另一端的应力较敏感。因此，奉节钻孔应变趋势异常变化是区域应力场应力传递的结果。     

Analytical correlation of a dynamic brace buckling experiment

A dynamic response analysis procedure for an x-braced tubular steel offshore platform frame is described, including details of the mathematical model adopted to represent the dynamic buckling behaviour of the brace member. Results obtained with this mathematical technique are compared with experimental data measured during shaking table tests of a 5/48 scale model frame. The agreement between experiment and analysis is excellent for different levels of response, ranging from linearly elastic to cyclic brace buckling.     

基于GT3的网格计算平台的构建及应用

基于CEDAGrid项目的需求, 通过应用Web服务技术和网格计算技术, 构建了基于GT3的网格计算应用平台, 在有4个节点的网格计算平台上(其中只有3个节点参与了科学计算任务)进行了地震应力触发计算实例(以川滇地区为例, 共有17个断层), 系统耗时为13min25s, 如果只在一个节点上进行计算, 则需要时间为35min10s。 该实例的成功运行证明, 基于网格技术构建的计算平台可以解决传统的地震领域内的科学计算问题, 在时间效率上可以提高许多, 如果应力触发计算本身越复杂, 网格的计算资源越丰富, 网格计算的执行效率会体现的越优越。 通过这一科学计算试验为网格技术在地震领域的应用做了有意的探索。     

中国数字测震台网专业软件评测

介绍我国“十五”期间建设测震台网专业软件评测平台基本架构及原理,举例描述了专业软件评测平台运行效果.认为,测震专业软件测试与评估对我国“十五”测震台网建设项目实施和提高台网运行质量发挥重要作用.