Seismic performance of double- skin steel- concrete composite box piers: Part Ⅰ——Bidirectional quasi-static testing

To study the seismic performance of double-skin steelconcrete composite box（ DSCB） piers, a total of 11 DSCB pier specimens were tested under bidirectional cyclic loading. The effects of the loading pattern, the steel plate thickness, the axial load ratio, the slenderness ratio and the aspect ratio were taken into consideration. The damage evolution process and failure modes of the tested specimens are presented in detail. Test results are also discussed in terms of the hysteretic curve, skeleton curve, ductility and energy dissipation capacity of DSCB pier specimens. It can be concluded that the hysteretic performance of DSCB piers in one direction is affected and weakened by the cyclic loading in the other direction. DSCB piers under bidirectional cyclic loading exhibit good performance in terms of load carrying capacity, ductility, and energy dissipation capacity. Overall, DSCB piers can meet the basic aseismic requirements. The research results can be taken as a reference for using DSCB piers as high piers in bridges in strong earthquakeprone areas.

Explosion resistance performance of reinforced concrete box girder coated with polyurea:Model test and numerical simulation

To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests.The reliability of the numerical simulation using LS-DYNA software was verified by the test results.The effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were studied.The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder.The top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local dent.The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen G.For the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of fracture.With the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more significant.The optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn.

Centrifugal model test and numerical simulation of vertical earth pressure on soft foundation box culvert

To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and the comparisons with the current methods to determine the load on a culvert were completed. The results of the model test and numerical analysis are in satisfactory agreement, which shows that the direction of the shear stress between the culvert and the adjacent embankment depends on the differential settlement between them. A vertical earth pressure concentration appears on the culvert with a rigid piles foundation because of a downward shear stress. The ratio of the load on a soft foundation culvert and the overburden pressure above the culvert raises first and then decreases as the backfill height increases. In order to reduce the load on a culvert, it is suggested to limit the stiffness difference of the foundations under the culvert and embankment and to use a light backfill over the culvert.

Concurrent Validity of a Virtual Version of Box and Block Test for Patients with Neurological Disorders

Background: The Box and Block clinical test is a validated and standardized scale for use in the clinical environment that allows the assessment of rough manipulative dexterity. Proposing virtual methods to carry out these assessments is an attempt to eliminate some of the subjectivity that the test may entail depending on the observer and the way in which the patient gives instructions. Applied to the assessment of skills after neurological pathologies, previous experiences in stroke patients have been found. So, this work was centered on the Spinal Cord Injury. Objective: To present the virtual application of the Box and Block scale, as well as details about its design and development for its manipulation based on Leap Motion Controller. Methodology: The relationship between the results obtained in the actual test and in the virtual application in healthy subjects and, mostly, patients with cervical spinal cord injury is analyzed, obtaining a high correlation index between both tests’ performance. Results: A high correlation index was obtained between both tests performance, the real and virtual version of the Box and Block Test. Conclusion: This virtual test can serve as an element to evaluate in the future the effectiveness of the RehabHand prototype based on virtual reality applications with a therapeutic and a rehabilitative sense that, manipulated from Leap Motion Controller, allow the improvement of the manipulative dexterity in patients with neurological diseases such as spinal cord injury.

Full-scale model tests and nonlinear analysis of prestressed concrete simply supported box girders

Full-scale model tests were carried out on a 30 m span prestressed concrete box girder and a 20 m span prestressed concrete hollow slab. Failure models were prestressed reinforcement tensile failure and crashing of roof concrete, respectively. The ductility indexes of the box girder and hollow slab were 1.99 and 1.23, respectively, according to the energy viewpoint. Based on the horizontal section hypothesis, the nonlinear computation procedure was established using the limited banding law, and it could carry out the entire performance analysis including the unloading, mainly focusing on the ways to achieve the unloading curves computation through stress-strain, moment-curvature and load-displacement curves. Through the procedure, parameters that influence on the bearing capacity, deformation performance and ductility of the structures were analyzed. Those parameters were quantity of prestressed reinforcement and tension coefficients of prestressed reinforcement. From the analysis, some useful conclusions can be obtained.

Box-Behnken响应面法优化“五味子-吴茱萸”药对的提取工艺及含量测定

目的:优化“五味子-吴茱萸”药对提取工艺并测定其不同配伍的化学成分含量。方法:利用Box-Behnken设计在单因素考察的基础上考察“五味子-吴茱萸”药对的提取工艺,确定最佳提取工艺,并通过高效液相色谱法测定“五味子-吴茱萸”的化学含量,确定药对的最佳比例。结果:“五味子-吴茱萸”药对最优提取工艺为乙醇体积分数70%,料液比1∶15(g/mL),提取时间60 min,提取次数3次。该提取工艺科学可靠。结论:本研究方法简单可行,可为“五味子-吴茱萸”药对的开发利用及相关研究提供参考。

An Experience of On-site PD Testing for Condition Monitoring of an 11 kV PILC Cable Insulation System

A cable circuit of a substation in the United Kingdom showed high level of PD activities during a survey using hand hold PD testing equipment. The authors were invited to carry out on-site PD testing experiment to further diagnose and locate the potential problem of the cable system. This paper presents the experience of the present authors carrying out the cable test. Following a brief introduction to the experiment equipments and physical connections, the paper analyses the data collected from the testing, including PD pulse shape analysis, frequency spectrum analysis and phase resolved PD pattern analysis. Associated with PD propagation direction identification, PD source diagnosis and localisation was made. Four different types of sensors, which were adapted during the testing, are shown to have different frequency bandwidths and performed differently. Aider comparing the parameters of the sensor and the PD signals detected by individual sensor, optimal PD monitoring bandwidth for cable system is suggested.

Scale Effects of Direct Shear Box on Behavior of Geogrid-Sand Interface

Direct shear test is one of the simplest and most economical tests to measure shear strength parameters of dry or saturated sandy soil as well as soil-geogrid interaction parameters.In the current study the effects of specimen size and density on soil-geogrid interaction parameters employing shear boxes of 6×6 cm,10×10 cm and 30×30 cm have been investigated.Results show that increasing specimen size of unreinforced sand with constant density results in a decrease in angle of friction which has been attributed to reduced confinement effect using larger shear boxes.The rate of reduction in angle of friction is increased by increasing soil density and using geogrid as reinforcement.

Discussion on Detection and Evaluation of Simply Supported Prestressed Concrete Small Box Girder Bridge After a Fire

The article takes a simply supported prestressed concrete small box girder bridge project as an example for inspection and evaluation after a fire incident.This includes appearance detection,concrete color hardness detection,concrete strength detection,concrete surface damage layer detection,reinforcement protective layer detection,and concrete carbonation detection.It is hoped that this analysis can be used as a reference for the detection and evaluation of future bridge projects with fire incidents to smoothen its subsequent repair and maintenance.

Strategy and Methodology of Integration Testing for GUI Software

In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.

Guideline of Test Suite Construction for GUI Software Centered on Grey-Box Approach

In this paper, the test suite construction for GUI (Graphical User Interface) software may be executed centered on grey-box approach with the prior test design of window access controls for unit testing, including front-end method of white box and follow-up black box method for integration testing. Moreover, two key opinions are proposed for the test suite construction for GUI software, the first one is that the “Triple-step method” should be used for unit testing with the prior disposing of data boundary value testing of input controls, and another one is that the “Grey-box approach” should be applied in integration testing for GUI software with necessary testing preparation in the precondition. At the same time, the testing of baseline version and the incremental testing should be considered for the test case construction to coordinate with the whole evolution of software product today. Additionally, all our opinion and thought are verified and tested with a typical case of GUI software—PQMS (Product Quality Monitoring Software/System), and results indicate that these methods and specific disposing are practical and effective.

一种车载T-BOX协议一致性测试系统及方法

为提升车联网系统无线车载终端(T-BOX)协议一致性测试准确度及场景覆盖度,降低实车道路极限工况测试潜在的安全风险,文章提出了一种基于试验室虚拟仿真环境的自动化测试系统及方法。通过自动化管理与执行单元调用自定义测试脚本,模拟导航卫星定位信号,仿真实车各类工况车载总线通信场景,构建多种典型电磁波传输信道模型及异常故障,实时解析处理车载T-BOX与虚拟云平台通信数据,自动判定测试结果并生成报告。该方法在提高测试准确性、覆盖度和安全性前提下,自动化建立闭环测试链路,有效缩短了产品开发测试周期。

Finite element failure analysis of continuous prestressed concrete box girders

In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity.

Selection of Example Varieties Used in the DUS Test Guideline of Tagetes L.

[Objective] Taking the characteristic of flower diameter of Tagetes L.as an example,this study aimed to select example varieties used in the DUS Test Guideline of Tagetes L.[Method] Two continuous years of measurements of flower diameter of 25 varieties were collected and then analyzed by using the box plot to illustrate the uniformity and stability of flower diameter of each variety.[Result] According to the information of variability,distribution symmetry of measurements and outliers of flower diameter of varieties provided by box plots,variety 16,2 and 4 were selected as the example varieties for the three expression states with respective flower diameter of 3.0-4.4,6.0-7.4 and 9.0-10.4 cm.[Conclusion] The box plot is an efficient method for the general analysis of varieties,which provides information covering the actual and possible expression range,median and outliers of measurements of flower diameter of each variety.It also provides references for selecting example varieties for other quantitative characteristics and evaluating the quality of varieties.

正交试验结合Box-Behnken响应面法优化靓靓胶囊水提取工艺

目的采用正交试验法结合Box-Behnken响应面法优化靓靓胶囊水提取工艺。方法以没食子酸、葛根素、芍药苷提取率以及水提物出膏率为指标,以液料比、提取时间、提取次数为因素,正交试验初步筛选工艺参数,BoxBehnken响应面法作进一步优化。结果最佳条件为液料比12∶1,提取两次,每次90 min,各指标相对误差均小于2%。结论正交试验结合Box-Behnken响应面法可减少靓靓胶囊水提取次数,降低生产成本。

Box-Behnken设计-响应面法优化桂枝茯苓胶囊的闪式提取工艺

目的:优化桂枝茯苓胶囊的闪式提取工艺。方法:以内刃转速、液固比、提取时间等为考察因素,以没食子酸、芍药苷、苯甲酸、肉桂酸、苯甲酰芍药苷、苦杏仁苷转移率的综合评价值为考察指标,在单因素试验基础上结合Box-Behnken设计-响应面法对桂枝茯苓胶囊闪式提取工艺进行优化;进行验证试验,并与常规的煎煮提取法(提取2次,共用时240 min)进行效果比较。结果:闪式提取桂枝茯苓胶囊的最优工艺为以水为提取溶剂,内刃转速5 600 r/min,液固比10.5:1,提取时间60 s。在此条件下验证试验的平均综合评价值为85.40%(n=3),与预测值85.55%的相对误差为0.15%,并高于煎煮提取法(72.65%)。结论:优化的闪式提取工艺用于桂枝茯苓胶囊的提取,具有高效、快速的特点。

基于Box-Behnken试验设计优化传统奶制马钱子的炮制工艺

目的:通过单因素结合Box-Behnken试验对马钱子的牛奶炮制工艺进行优化。方法:在单因素试验的基础上,以炮制时间、浸泡时间、牛奶倍量为自变量,以马钱子碱和士的宁的含量为因变量,采用Box-Behnken试验设计,优化马钱子的牛奶炮制工艺。结果:最佳炮制工艺为生马钱子浸泡6 d,润后取出,刮去外种皮、去掉胚芽,加入9倍量牛奶,加热提取1.5 h。结论:优化出的牛奶炮制马钱子制备工艺,具有工艺可控、操作简便的特点,适合工业生产。

Box-Cox转换在估计危险因素平均暴露剂量中的应用

目的 :Box -Cox转换在估计危险因素平均暴露剂量中的应用。方法 :用Stata软件包进行数据的Box -Cox转换 ,并用转换后的数据计算暴露剂量算术平均数。结果 :大多数的氡子体暴露计量的数据不呈正态分布 ,只有约 2 1%的原始数据适合用算术平均数代表 ;Box -Cox转换后所有数据都可以计算出有代表性的氡子体暴露剂量平均水平。结论 :在估计环境危险因素的年平均暴露剂量时 ,若原始数据分布不呈正态或近似正态 ,应当先进行数据转换。Box -Cox转换是一种适用范围较广的数据转换方式 ,在估计放射性氡子体平均暴露剂量时 ,结果令人满意。

基于PSD谱的SCR box频域加速耐久试验

介绍了冲击响应谱(SRS)和疲劳损伤谱(FDS)等概念在描述零件的全寿命损伤和冲击响应上的应用。以某重型车选择性催化还原器(SCR box)为研究对象,提出了通过道路采集时域信号合成加速度PSD谱控制振动台的频域加速耐久试验方法。与现有室内试验方法相比,在失效模式相同和损伤等效的前提下,实现了台架试验与试车场道路试验相关联,并大大缩短了试验时间,解决了SCR box耐久开发难题。

利用BOX-COX变换改进加速寿命模型的研究

在加速寿命试验中,产品的寿命通过加速方程和所承受的应力水平密切相关。以往常用的三种加速模型为幂律模型、阿伦尼斯模型和伊林模型。利用BOX-COX变换改进加速寿命模型,提出了一种加速寿命模型族,幂律模型、阿伦尼斯模型和伊林模型作为这种模型族的特例。仿真算例验证了BOX-COX加速模型族的适用性。