别桥商会会长宋保兴坚守抗洪第一线

7月6日笔者来到地处茅山革命老区的溧阳市别桥镇东溪村、乌荡湾圩堤抗洪第一线,看到了别桥商会会长、江苏富民新材料有限公司董事长宋保兴,正在圩堤上指挥抗洪抢险小分队加固圩堤。在抗洪现场的一位女职工顾岑告诉我们：＂宋会长已经五天四夜在这里指挥抗洪抢险了,晚上实在吃不消,就坐在圩堤边打个盹继续战斗。＂

Operational modal identification of suspension bridge based on structural health monitoring system

An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The methods are applied to the operational modal identification system of the Runyang Suspension Bridge, which can be used to obtain the modal parameters of the bridge from out-only data sets collected by its structural health monitoring system （SHMS）. As an example, the vibration response data of the deck, cable and tower recorded during typhoon Matsa excitation are used to illustrate the program application. Some of the modal frequencies observed from deck vibration responses are also found in the vibration responses of the cable and the tower. The results show that some modal shapes of the deck are strongly coupled with the cable and the tower. By comparing the identification results from the operational modal system with those from field measurements, a good agreement between them is achieved, but some modal frequencies identified from the operational modal identification system （OMIS）, such as L1 and L2, obviously decrease compared with those from the field measurements.

DAMAGE ANALYSIS AND LOCATION OF RUNYANG BRIDGE USING MULTI-LAYER PERCEPTRON

A damage location method using multi-layer perceptron （MLP） is developed to diagnose the cable damage of a real long span cable-stayed bridge. Firstly, the damage patterns are defined based on dynamical calculation. The analysis of damage pattern reveals that the damage patterns caused by different damage locations have inherent distinctness, while the damage extent only linearly amplifies the damage pattern curves. And 4th, 6th and 7th order frequencies are canceled from the patterns because of their insensitiveness to cable damage. Then a MLP network is designed by trail-error method to describe the 7-D mapping space of damage pattern. Identification results prove that the properly organized MLP can grasp the damage pattern and identify the damage location.

农机推广:抓好选好节点

金秋时令,＂四秋＂大忙自南向北拉开帷幕,苏南水稻产区逐渐步入抢收抢种的繁忙时节。江苏溧阳市埭头、别桥等乡镇的农机合作社根据地域特点,在＂四秋＂收种农事里,注重选好农机推广应用节点,着力推进农机化事业发展。2014年＂四秋＂,他们的农机合作社主打烘干,同时耕翻播种兼备,统筹兼顾,全力推进农机化产业服务,保障秋收秋种质量。溧阳市海斌农机合作社自有200余hm2水稻抢收任务,同时还需为周边农户266.7余hm2水稻抢收与麦子抢种提供＂一条龙＂农机化服务。

侨讯园地

在国家侨务政策和富民政策扶持下,江苏省溧阳市别桥镇陈巷村侨眷马姗华先是办起了服装店,后又办起了手套厂,现已拥有固定资产100多万元,厂房2500平方米,工人300多名,月产手套五万打,年产值500万元,1993年出口创汇60万美元,上交税收10万元,是江苏省最大的一家私营手套生产企业。 1980年初,马姗华第一个在别桥镇办起了个体服装店。她生意越来越好,名气越来越大。尔后,她决心走走大都市。

Study on effects of environmental temperature on dynamic characteristics of Taizhou Yangtze River Bridge

The dynamic characteristics of three-tower and two-span suspension bridge are analyzed at different global temperatures. An equivalent cable inner force method is proposed to consider temperature effects and to study the effects of environmental temperature on dynamic characteristics of Taizhou Yangtze River Bridge. The result demonstrates that the effects of temperature can not be neglected in static or dynamic analysis of Taizhou Yangtze River Bridge. The relationship between temperature and frequency is negative. The effects of temperature should be taken into account in experimental modal analysis of long-span bridges and damage identification.

Damage Identification in Footbridges from Natural Frequency Measurements

The present study aims to develop a robust structural damage identification method that can be used for the evaluation of bridge structures. An approach for the structural damage identification based on the measurement of natural frequencies is presented. The structural damage model is assumed to be associated with a reduction of a contribution to the element stiffness matrix equivalent to a scalar reduction of the material modulus. A computational procedure for the direct iteration technique based on the non-linear perturbation theory is proposed to identify structural damage. The presented damage identification technique is applied to the footbridge over the Slunjcica River near Slunj to demonstrate the effectiveness of the proposed approach. Using a limited number of measured natural frequencies, reduction in the stiffness of up to 100% at multiple sites is detected. The results indicate that the proposed approach can be successful in not only predicting the location of damage but also in determining the extent of structural damage.

Damage alarming of long-span suspension bridge based on GPS-RTK monitoring

Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions.

State Representation Methodology （SRM） for Bridge Condition Assessment in SHM

This paper introduces a new concept of ＂State Representation Methodology （SRM）＂ which is a kind of bridge condition assessment method for structural health monitoring system （SHM）. There are many methods for system identification from the simplicity comparison of damage index to the complicated statistical pattern recognition algorithms in SHM. In these methods, modal analysis and parameters identification or many defined indices are common-used for extracting the dynamic or static characteristics of a system. However, there is a common problem： due to the complexity of a large size system with high-order nonlinear characteristics and severe environment interference, it is impossible to extract and quantify exactly these modal parameters or system parameters or indices as the feature vectors of a system in damage detection in an easy way. The SRM considered a more general theory for the non-parametric description of system state.

Seismic performance evaluation for super-long span cable-stayed bridges

Based on the capacity/demand(C/D)analysis of bridge components,and life cycle and performance based seismic design principles,a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges.According to the approach,the seismic performance evaluation of the Sutong Bridge,which is a cable-stayed bridge with a main span of 1 088 m,is completed,and the practicality of the approach is validated.The earthquake resistance level for super-long span cable-stayed bridges is discussed,including the earthquake level,its corresponding structural performance and check indices.And a set of formula for capacity/demand ratio calculation of bridge components is proposed.

Identification of Suspension Bridge Parameters under Exploitational Conditions

The paper concerns a research into dynamic properties of the steel suspension bridge across Opolska Street in Krakow, Poland. Parameter identification was carried out with the application of the nonlinear system identification method on the basis of system responses to exploitational excitation resulting from pedestrian traffic. In order to verify obtained results, on the basis of the geometrical and material properties of the considered system, the FEM （finite elements model） was created. Created FEM model was updated through the comparison with the model determined by the use of experimental modal analysis method and then applied to analytical evaluation of the considered suspension bridge natural frequencies.

营造适合每个孩子成长的绿色家园

创办于1931年的古渎小学,位于河渠交错、沟塘密布的＂江南水乡、鱼米之地＂别桥镇。随着拆乡并镇城市化进程的加快,古渎小学人数锐减,一个年级只有一个班级,在校学生数不足200人。我们依据地方特色与学校实际,提出了＂营造适合每个孩子幸福成长的绿色家园＂的办学理念,确立了建设＂成功乐园·幸福校园·绿色家园＂的办学愿景,明确了知感恩、明责任、会合作、能分享、强体魄、有自信的培养目标。

为了红色沃土的振兴——记江苏省溧阳市海斌农机专业合作社理事长王海斌

溧阳市海斌农机专业合作社地处茅山革命老区的江苏省溧阳市别桥镇西部,与金坛接壤。合作社2006年成立,现拥有成员584户,各种农业机械269台（套）,带动周边大户包括家庭农场6000多亩;服务范围覆盖16个行政村的6708户;年加工销售大米1.2万吨,成为当地服务面积最大的农机合作社。2014年6月被授予＂常州市农业产业化经营龙头企业＂称号。

《现代航空航天工业质量管理》一书审稿会在北京召开

部质量司、质量管理协会共同组织编写的《现代航空航天工业质量管理》一书,经过全体编写人员两年多的辛勤劳动,各章、节均已陆续完稿,为保证全书的系统性、正确性、协调性,于1990年6月29日至7月1日在北京召开了全书的审稿会会。

Self-contained eigenvector algorithm applied to the identification of aerodynamic derivatives of bridge model

On one hand, when the bridge stays in a windy environment, the aerodynamic power would reduce it to act as a non-classic system. Consequently, the transposition of the system’s right eigenmatrix will not equal its left eigenmatrix any longer. On the other hand, eigenmatrix plays an important role in model identification, which is the basis of the identification of aerodynamic derivatives. In this study, we follow Scanlan’s simple bridge model and utilize the information provided by the left and right eigenmatrixes to structure a self-contained eigenvector algorithm in the frequency domain. For the purpose of fitting more accurate transfer function, the study adopts the combined sine-wave stimulation method in the numerical simulation. And from the simulation results, we can conclude that the derivatives identified by the self-contained eigenvector algorithm are more dependable.

Damage identification method of girder bridges based on finite element model updating and modal strain energy

A timely and accurate damage identification for bridge structures is essential to prevent sudden failures/collapses and other catastrophic accidents.Based on response surface model(RSM)updating and element modal strain energy(EMSE)damage index,this paper proposes a novel damage identification method for girder bridge structures.The effectiveness of the proposed damage identification method is investigated using experiments on four simply supported steel beams.With Xiabaishi Bridge,a prestressed continuous rigid frame bridge with large span,as the engineering background,the proposed damage identification method is validated by using numerical simulation to generate different bearing damage scenarios.Finally,the efficiency of the method is justified by considering its application to identifying cracking damage for a real continuous beam bridge called Xinyihe Bridge.It is concluded that the EMSE damage index is sensitive to the cracking damage and the bearing damage.The locations and levels of multiple cracking damages and bearing damages can be also identified.The results illuminate a great potential of the proposed method in identifying damages of real bridge structures.

Fuzzy finite element model updating of bridges by considering the uncertainty of the measured modal parameters

It is significant to consider the effect of uncertainty of the measured modal parameters on the updated finite element(FE) model,especially for updating the FE model of practical bridges,since the uncertainty of the measured modal parameters cannot be ignored owing to the application of output-only identification method and the existence of the measured noise.A reasonable method is to define the objective of the FE model updating as the statistical property of the measured modal parameters obtained by conducting couples of identical modal tests,however,it is usually impossible to implement repeated modal test due to the limit of practical situation and economic reason.In this study,a method based on fuzzy finite element(FFM) was proposed in order to consider the effect of the uncertainty of the measured modal parameters on the updated FE model by using the results of a single modal test.The updating parameters of bridges were deemed as fuzzy variables,and then the fuzzification of objective of the FE model updating was proposed to consider the uncertainty of the measured modal parameters.Finally,the effectiveness of the proposed method was verified by updating the FE model of a practical bridge with the measured modal parameters.