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1

Możliwe straty spowodowane w Polsce wichurami, trąbami powietrznymi i szkwałami

Chmielewski T., Szer J.

Inżynier Budownictwa

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2018

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nr 1

26--31

2

Kaiser effect observation in reinforced concrete structures and its use for damage assessment

Vidya Sagar R., Raghu Prasad B. K., Singh R. K.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

548--557

EN

Reinforced concrete (RC) beams of span 3 m were tested under incremental cyclic load at different loading rates and simultaneously during the fracture process in the RC beams acoustic emissions (AE) were recorded. An attempt has been made to study the Kaiser effect as a measure of damage in RC beams. It was observed that RC beams made with high strength concrete under incremental cyclic loading showed an obvious Kaiser effect before the failure load. The results may be useful to study the damage in concrete structures and provide a reference for the application of Kaiser effect in engineering practice.

3

Influence of test conditions on modal characteristics of reinforced concrete structures under different damage scenarios

Srinivas V., Sasmal S., Ramanjaneyulu K., Jeyasehar C. A.

Archives of Civil and Mechanical Engineering

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2013

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Vol. 13, no. 4

491--505

EN

In the present work, studies are carried out on experimental modal analysis of reinforced concrete structural members for damage assessment using linear and nonlinear vibration characteristics at different levels of damage. Parameters such as support conditions, type and level of excitation etc. are found to have prominent influence on vibration characteristics. Experimental investigations have been carried out to estimate the influence of these parameters on the vibration characteristics of reinforced concrete structures. Based on the investigations using different excitation mechanisms, it is noted that resolution of modal responses in the case of burst random is much better when compared to true random excitation. The excitation type and force levels are found to have considerable influence on vibration characteristics. It is opined that judicious selection in using the type of excitation, level of excitation force plays important role especially when evaluating the vibration characteristics of reinforced concrete structures for damage assessment.

4

Damage evaluation of a town's sewage system in southern Poland by the preliminary hazard analysis method

Królikowska J.

Environment Protection Engineering

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2011

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Vol. 37, nr 4

131-142

EN

In the paper, the technical risk has been evaluated for the sewage network of a city in Southern Poland. The basis for calculations were field studies concerning operation of the said network, with the focus on technical data (network type, length, materials, size) and the failure rate information (type and duration of failure, unwanted event frequency). A two-dimensional matrix for failure risk in the pipelines was prepared with consideration to the type of pipeline and the material, as well as a risk map for pipeline malfunction. Obviously, the number of factors may be extended. In order to perform such analyses and add new factors, an appropriate database is needed, while in the case of sewage systems there is still little data collected. The evaluated risk of failure for the studied network was discovered to be in the tolerated and controlled-risk groups. The matrices and technical risk maps can prove to be useful in the process of optimizing the operation of the sewage network, e.g. in planning and executing repair works.

5

Studies on woollen threads from historical tapestries

Odlyha M., Theodorakopoulos C., Campana R.

Autex Research Journal

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2007

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Vol. 7, no. 1

9--18

EN

Fourier transform (FTIR) attenuated total reflectance (ATR) and second derivative spectroscopy has been used for the first time to evaluate the state of degradation in historical woollen threads from the collections of Flemish tapestries (15th-17th centuries) in the Royal Palace, Madrid, Hampton Court Palace, and museums in Brussels. The work was performed as part of the EC-funded project "Monitoring of Damage in Historic Tapestries", also known as the MODHT project [1]. The overall aim was to develop procedures for recognising tapestries at risk and provide analysis for informing collection care. Prior to the testing of the historical threads, model tapestries were prepared according to traditional techniques of weaving and dyeing. They were then subjected to accelerated light ageing. This paper reports on the part of the MODHT project in which ATR-FTIR was used. It was selected since it is a non-destructive method, and also because it has previously been used to study the oxidation products of cystine in wool and to provide a semi-quantitative assessment of change [2]. Evaluation was conducted on the model tapestries, and the cysteic acid peak was selected as the marker for change, as it showed a systematic change with light ageing. The same marker was used to assess the change in historical threads.