Dong-Sheng Li

Universität Siegen · Department of Mechanical Engineering

Traditional vibration-based detection methods seek to detect structural damage based on changes in dynamic features, which assume that changes in dynamic features are solely caused by structural damage. However, environmental and operational variations (EOV) significantly influence structural dynamic features, and these changing conditions can caus...

Vibration-based damage detection relies on the observation of changes in damage-sensitive dynamic features. However, a major problem is that dynamic features are sensitive not only to structural damage but also to environmental and operational variations (EOVs), such as temperature, humidity, and operational loading. In addition, the influence of E...

Jacket platform is the marine structure that anchor piles to the sea floor, among which the leg is one of the most important components of fixed marine structure. Most of the existing stress and strain monitoring methods for offshore platform ignore the existing forces in the structures caused by deck load and installation errors before the monitor...

Pipelines provide an economical mode of transportation for hauling gas and liquids such as oil over long distances. Pipeline explosions cause massive loss of lives, and adversely impact both the environment and the economy. Accurate and automated detection of the arrival times of negative pressure waves (NPW) because of leakages is the key paramete...

Pipeline, serving as one of the most important gas transportation methods, can cause serious consequences in the event of leakage, so leakage monitoring is particularly important. In our previous study, a fiber Bragg grating hoop strain sensor was developed to detect pipeline leakage by measuring circumferential strain, and this sensor was utilized...

The conventional extended Kalman filter (EKF) for detecting structural damage with measured responses is a dynamic inverse problem. With the increase in size of the extended state vector, EKF suffers from low accuracy and convergence difficulty due to the ill‐condition of the inverse problem and increased computational error. To overcome the aforem...

Pipeline is an important structure to transport oil and gas through long distances. However, pipeline also suffers from many threats especially corrosion and leakage. Therefore, it is necessary to conduct pipeline safety monitoring. With the advantage of high precision in distributed strain measurement, the optical frequency domain reflectometry (O...

This paper describes the backgrounds, motivations and recent history of structural health monitoring (SHM) developments to various types of engineering structures. Extensive applications of SHM technologies in bridges, high-rise buildings, sport avenues, offshore platforms, underground structures, dams, etc. in mainland China are summarily categori...

Researchers and administrative authorities have long recognized the significance of implementing long-term structural health monitoring (SHM) systems for civil infrastructures, especially large-span space structures or other complex infrastructures, in order to secure structural safety and issue warnings regarding the structural damage prior to cos...

A structural health monitoring system consists of permanently installed sensors to collect structural information, and these sensors are required to be placed at 'good' positions for damage identification. Conventional sensor placement methods make use of dynamic characteristics of a structure, i.e., mode shapes and natural frequencies, to determin...

Ice load is one of the most dangerous factors which threaten the health of offshore structures in cold area. The ice-loading model experiment is an effective method to identify the ice load and to evaluate its influence towards structures. Fiber Bragg grating (FBG) with advantages of reliability, durability and high accuracy, has become one of the...

The importance of real-time detection of cable force during stretching construction can hardly be overstated, especially in long-span space cable system. In this paper, a novel approach to monitor the cable structure health using fiber Bragg grating (FBG) sensors was elaborated and applied in monitoring the tensioning process of suspend-cable dome...

Fiber Bragg grating (FBG) sensors have attracted a considerable amount of interest for their superior characteristics. However, the FBG sensors made on bare fibers are easily damaged. For their safe use in engineering, the glass core of optical fibers is coated with softer low modulus protective coatings. A portion of the host material strain is ab...

A novel sensor placement criterion is proposed for structural health monitoring after five influencing criteria are critically reviewed. The objective of the proposed criterion is to achieve best identification of modal frequencies and mode shapes through almost unbiased estimation of modal coordinates. The proposed criterion derived by the Represe...

A simple and fast computational algorithm of the Effective Independence for sensor placement is presented in the paper. It is based on the relationship between the Effective Independence and Modal Kinetic Energy method, and on a downdating algorithm of the QR decomposition for a reduced modal matrix. Traditional computations of the Effective Indepe...

Nomenclature: M = mass matrix of a structure K = stiffness matrix of a structure C = Rayleigh damping matrix of a structure Φ = rectangular mode shape matrix (, and Φ m n× ∈ R n m ≤) n = scalar number of candidate sensor positions m = scalar number of target mode shapes to be identified or correlated s = scalar desired number of sensors to be place...

When a fiber Bragg grating (FBG) sensor is embedded in a structure to sense its strain, a portion of strain is absorbed by the protective interlayer of the fiber optical sensor. If an angle exists between the FBG sensor axis and external principal stress direction of the host material, the strain transfer from the host material to the sensor will b...

Fiber Bragg grating (FBG) sensors show superior potential for structural health monitoring of civil structures to ensure their structural integrity, durability, and reliability. In this work, FBG sensors, including strain and temperature sensors, are applied for health monitoring of the oil production offshore platform number CB271, which is locate...

This paper presents an overview of current research and development in the field of sensor placement methods in structural health monitoring. Due to the limitations of equipment facilities and cost, the number of sensors to be installed in a structure is relatively few. In many cases, three are always degrees of freedoms in a structure are not easi...

Optic fiber Bragg grating sensor is a new type of sensor, which plays an important role in structural healthy monitoring. When the optic fiber Bragg grating sensor is embedded in the structure or adhered to the structure, there is a strain transferring course between structure and sensor for the existence of interlayer. Important factors that affec...

The past decade has seen rapid advances in research, development, and application of optical fiber Bragg grating technology. Sensors based on this technology have special advantages of being lightweight and small in size, inert and corrosion resistant, immune to electromagnetic interference (EMI), easily multiplexed and multifunctional (they can me...

We develop an analytical model for the relationship between the strain measured by a fiber Bragg grating sensor and the actual structural strain. The values of the average strain transfer rates calculated from the analytical model agree well with available experiment data. Based on the analytical model, the critical adherence length of an optical f...

The relationship between the strains measured by a fiber Bragg grating sensor and the actual structural strains is deduced, then the average strain transfer rate computed by the formulation developed in this paper is compared with available experimental data. The critical adherence length of an optical fiber sensor is determined by a strain lag par...

Optical fiber sensors have received increasing attention in the fields of aeronautic and civil engineering for their superior ability of explosion proof, immunity to electromagnetic interference and high accuracy, especially fitting for measurement applications in harsh environment. In this paper, a novel FBG (fiber Bragg grating) strain sensor, wh...

This paper presents an overview of current research and development in the field of structural health monitoring with civil engineering applications. Specifically, this paper reviews fiber optical sensor health monitoring in various key civil structures, including buildings, piles, bridges, pipelines, tunnels, and dams. Three commonly used fiber op...

Optical fiber sensors show superior potential for structural health monitoring of civil structures to ensure their structural integrity, durability and reliability. Apparent advantages of applying fiber optic sensors to a marine structure include fiber optic sensors' immunity of electromagnetic interference and electrical hazard when used near meta...

This paper presents a new approach to reduce the seismic responses of spatial structures with magneto-rheological (MR) dampers using genetic algorithm with small populations (/spl mu/GA). /spl mu/GA is used to obtain the controller for the MR dampers for structural vibration reduction that is difficult to be solved by the classical optimal control....

A new method for identifying dynamic parameters of a structure by measuring its first several frequencies and mode shapes is presented in this paper. Accurate estimates of the dynamic characteristics of a structure using limited measurement data are necessary for applications such as damage localization and finite element model verification. This m...

A method is presented for the selection of a set of sensor locations from a larger candidate sent for the purpose of structural loading identification. The method ranks the candidate sensor locations according to their effectiveness for identifying the given known loadings. Measurement locations that yield abnormal jumps in identification results o...

In civil engineering, the smart health monitoring method by use of fiber optic sensor is a new approach that evaluates the structural health situation. The current status in applications of fibre optic structural health monitoring in civil engineering structures with a brief introduction of the advantages, basic principles of fibre optic sensors is...