References of "Erdenebat, Dolgion 50008823"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCurvature based DAD-method for damage localisation under consideration of measurement noise minimisation
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Teferle, Felix Norman UL

in Engineering Structures (2019), 181

Several research projects on condition assessment of bridges have proven that structural responses from dynamic excitation or static loading are influenced by local damages and thus, could be used for the ... [more ▼]

Several research projects on condition assessment of bridges have proven that structural responses from dynamic excitation or static loading are influenced by local damages and thus, could be used for the detection and localisation of damages. Particularly, the curvature of structures is directly depending on their stiffness. In order to localise the discontinuities in curvature lines resulting from damage, this paper uses the so-called Deformation Area Difference Method (DAD), which is based on static load deflection tests on bridge structures. The DAD-method for damage localisation is presented within the paper using a theoretical example, which is then verified by two laboratory experiments. The first experiment consists of a reinforced concrete beam, which is loaded stepwise until failure of the concrete in the compression zone. Due to the load increase, the tensile zone of the beam starts cracking, leading to a stiffness reduction. The application of the DAD-method allows identifying the cracked area from the measurement of the deflection line. However, a challenge and a prerequisite for the applicability of the DAD-method is the highly accurate measurement of the deflection line. Therefore, one of the most modern measurement techniques such as digital photogrammetry is applied. Nonetheless, the accuracy of each measurement technique is limited. The second laboratory experiment consists of a steel beam, which is locally damaged at three positions. The degree of the damage is stepwise increased in order to identify at which degree of damage the applied DAD-method is still able to identify and localise damage. In this work, the focus lies on the minimisation of the effect of noise resulting from the limited measurement precision. Possible solutions were examined and proposed based on methods such as data smoothing using polynomial regression, consideration of standard deviation and measurement point variation. The reduction of the noise effect leads to an increase in the sensitivity of the damage localisation. The DAD-method has proven its potential for practical application through the successful localisation of cracking in the concrete beam. [less ▲]

Detailed reference viewed: 119 (29 UL)
Full Text
Peer Reviewed
See detailStatic load deflection experiment on a beam for damage detection using the Deformation Area Difference Method
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Teferle, Felix Norman UL

Scientific Conference (2018, October)

A reliable and safety infrastructure for both transport and traffic is becoming increasingly important today. The condition assessment of bridges remains difficult and new methods must be found to provide ... [more ▼]

A reliable and safety infrastructure for both transport and traffic is becoming increasingly important today. The condition assessment of bridges remains difficult and new methods must be found to provide reliable information. A meaningful in-situ assessment of bridges requires very detailed investigations which cannot be guaranteed by commonly used methods. It is known that the structural response to external loading is influenced by local damages. However, the detection of local damage depends on many factors such as environmental effects (e.g. temperature), construction layer (e.g. asphalt) and accuracy of the structural response measurement. Within the paper, a new so-called Deformation Area Difference (DAD) Method is presented. The DAD method is based on a load deflection experiment and does not require a reference measurement of initial condition. Therefore, the DAD method can be applied on existing bridges. Moreover, the DAD method uses the most modern technologies such as high precision measurement techniques and attempts to combine digital photogrammetry with drone applications. The DAD method uses information given in the curvature course from a theoretical model of the structure and compares it to real measurements. The paper shows results from a laboratory load-deflection experiment with a steel beam which has been gradually damaged at distinct positions. The load size is chosen so that the maximum deflection does not exceed the serviceability limit state. With the data obtained by the laboratory experiment, the damage degree, which can still be detected by the DAD method, is described. Furthermore, the influence of measurement accuracy on damage detection is discussed. [less ▲]

Detailed reference viewed: 112 (27 UL)
Full Text
Peer Reviewed
See detailThe Deformation Area Difference (DAD) method for condition assessment of reinforced structures
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Scherbaum, Frank et al

in Engineering Structures (2018), 155

The investigation and condition assessment of bridges have a very high priority in the construction industry today. Particularly, due to the fact that many bridge structures are getting old and partly ... [more ▼]

The investigation and condition assessment of bridges have a very high priority in the construction industry today. Particularly, due to the fact that many bridge structures are getting old and partly reach the end of their useful life, the control and condition assessment of bridge structures have become very important and essential. The present research work introduces an efficient new method for condition assessment called the Deformation Area Difference (DAD) Method. This new method represents an attractive alternative to visual inspection and long-term monitoring. In this paper, the new method with its theoretical background is presented and explained by means of a laboratory experiment and some additional theoretical calculation examples. The experimental investigations have been realised on a reinforced concrete beam, which has been gradually loaded until failure. For each load step, the stiffness reduction and the apparent cracking have been monitored. High-precision measurements such as close-range photogrammetry, digital levelling and displacement sensors have been used for the determination of the deflection curve. The DAD method has been applied to identify the area of the crack pattern of the laboratory experiment. Furthermore, the method is discussed with regard to the load level and the precision of the deformation measurements. On the basis of the laboratory experiment, the applicability of the DAD method for damage detection could be proven. Furthermore, the sensitivity of the method with regard to the damage degree, the static system, the damage position and the impact of temperature variation were analysed. [less ▲]

Detailed reference viewed: 196 (74 UL)
Full Text
Peer Reviewed
See detailLaboratory experiment for damage assessment using the DAD-method
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Teferle, Felix Norman UL

in Conference proceedings SMAR 2017 (2017, September)

In the following, a new analytical method, the Deformation Area Difference (DAD) method for damage assessment of bridge structures is applied using experimental test results of a statically loaded beam ... [more ▼]

In the following, a new analytical method, the Deformation Area Difference (DAD) method for damage assessment of bridge structures is applied using experimental test results of a statically loaded beam. An essential prerequisite for the application of this method is a high precise measurement of the deflection line. In this paper, the results from a laboratory experiment using modern measurement techniques such as photogrammetry and displacement sensors are discussed. A reinforced concrete beam is stepwise loaded until reaching the ultimate limit state. The DAD-method is applied to the resulting data from the measurements and the outcome is discussed for further optimisation of the method. In principle, the measured deflection line of the beam contains already essential information on discontinuities which occur due to cracking. These entries are processed and visualised using the DAD-method. This study shows that a high accuracy of the measurement techniques in combination with the DAD-method can become an effective tool for damage detection. [less ▲]

Detailed reference viewed: 106 (23 UL)
Full Text
Peer Reviewed
See detailCondition assessment and damage localisation for bridges by use of the Deformation Area Difference Method (DAD-Method)
Erdenebat, Dolgion UL; Waldmann, Danièle UL

in Performance-based approaches for concrete structures (2016, November)

Already today, a huge number of bridges are in an ailing condition due to their increasing age and due to an increased traffic volume, especially of heavy transport vehicles. To assess their load bearing ... [more ▼]

Already today, a huge number of bridges are in an ailing condition due to their increasing age and due to an increased traffic volume, especially of heavy transport vehicles. To assess their load bearing capacity and subsequently predict their remaining life span, every bridge needs to be analysed by con-dition assessment. The consequences of unreliable condition assessment should not be underestimated, as most bridge constructions constitute cost intensive and indispensable infrastructures. Thus, modern condition assessment methods, easy and obvious in their application, are needed in order to reduce future investigations. To offer an easy handling alternative to evaluate the condition of bridges, the Deformation Area Dif-ference Method has been developed. Hereby, the accruing deformation of bridges under a static load will be analysed with the help of modern measurement equipment. Therefore, the resulting defor-mation curves like the deflection, the inclination angle and the curvature curves, will be analysed in one diagram together with the results out of initial measurements or theoretically calculated defor-mation curves. The DAD-Method is then applied on the surface difference area between those two curves for the deflection, the inclination and the curvature. It will be demonstrated that a localisation of damage is possible, independent from the degree of damage. In this study, the applicability of the DAD-Method including the comparison of innovative measure-ment techniques using a laboratory specimen is investigated. For further explanation of the back-ground of the DAD-Method, the results from a FE-calculation are presented. [less ▲]

Detailed reference viewed: 249 (67 UL)
Full Text
Peer Reviewed
See detailNumerical investigation of bridges with the aim of condition assessment in applying the Deformation Area Difference method (DAD-method) and selecting appropriate measurement techniques
Erdenebat, Dolgion UL; Waldmann, Danièle UL; Teferle, Felix Norman UL

in 5th International Symposium on Life-Cycle Civil Engineering (IALCCE 2016), Delft (2016, October)

Condition assessment of existing road bridges gains ever increasing importance today as bridges are getting older and the inflow of heavy traffic is constantly increasing. The further development of ... [more ▼]

Condition assessment of existing road bridges gains ever increasing importance today as bridges are getting older and the inflow of heavy traffic is constantly increasing. The further development of recognized techniques and the development of new methods for early and accurate detection of damage to the structure are made possible by means of innovative technological progress. In this contribution, the principles of Defor-mation Area Difference Method (DAD-Method) for condition assessment of bridges are presented. This method is based on the further processing of measured and computed deformation values. The application of the DAD-Method requires a precise recording of the deflection of a load-deflection test. On the basis of theoretical cal-culations, this method has allowed to identify as well as to localise damage to a structure. The DAD-Method is independent of a reference measurement and insensitive to global influences such as temperature fluctuations. For precise detection of deformations, the most modern measuring instruments and methods like photogram-metry, total stations, displacement sensors, strain gauges and levelling are compared to each other. In collabo-ration with the appropriate measurement technology, the localisation of damage in bridges becomes possible. [less ▲]

Detailed reference viewed: 234 (49 UL)
Full Text
Peer Reviewed
See detailInvestigation of temperature-dependent stiffness variation of a layer of asphalt and their possible effect on the deformation behaviour of concrete structures
Waldmann, Danièle UL; Erdenebat, Dolgion UL; Scherbaum, Frank et al

in 6th International Conference on Experimental Vibration Analysis for Civil Engineering Structures, Duebendorf 2015 (2015, October)

In the time of increasing maintenance costs, the continuous inspection and the earliest possible damage detection become more and more important. In order to minimize future maintenance costs, the exact ... [more ▼]

In the time of increasing maintenance costs, the continuous inspection and the earliest possible damage detection become more and more important. In order to minimize future maintenance costs, the exact evaluation of the condition of the structure and the exact assessment of potential damages are of essential importance. Therefore the University of Luxembourg carries out projects to investigate an efficient application of different assessment methods taking into account praxis relevant test conditions. As a part of this project especially the changing temperatures which influence the stiffness of the materials are analysed. As a consequence, for the condition assessment of structures, the asphalt layer cannot only be taken into consideration as a mass applied as load on the structure. Due to bond effects of the asphalt layer to the load carrying element its changing stiffness induced by changing temperatures influences the stiffness of the whole structure. Within this paper this effect will be illustrated. First the load carrying behaviour and the stiffness of pre-stressed concrete slabs realized with and without an additional asphalt layer will be investigated in a climate chamber and the results will be compared for different temperatures. [less ▲]

Detailed reference viewed: 250 (64 UL)