Model Validation and Simulation

The Bauhaus Summer School series provides an international forum for an exchange of methods and skills related to the interaction between different disciplines of modern engineering science. The 2012 civil engineering course was held in August over two weeks at Bauhaus-Universität Weimar. The overall aim was the exchange of research and modern scientific approaches in the field of model validation and simulation between well-known experts acting as lecturers and active students. Besides these educational intentions the social and cultural component of the meeting has been in the focus. 48 graduate and doctoral students from 20 different countries and 22 lecturers from 12 countries attended this summer school. Among other aspects, this activity can be considered successful as it raised the sensitivity towards both the significance of research in civil engineering and the role of intercultural exchange. This volume summarizes and publishes some of the results: abstracts of key note papers presented by the experts and selected student research works. The overview reflects the quality of this summer school. Furthermore the individual contributions confirm that for active students this event has been a research forum and a special opportunity to learn from the experiences of the researchers in terms of methodology and strategies for research implementation in their current work

Nonlinear Analysis of Structures: Wind Induced Vibrations

The proceedings at hand are the result of the International Master Course Module: "Nonlinear Analysis of Structures: Wind Induced Vibrations" held at the Faculty of Civil Engineering at Bauhaus-University Weimar, Germany in the summer semester 2019 (April - August). This material summarizes the results of the project work done throughout the semester, provides an overview of the topic, as well as impressions from the accompanying programme. Wind Engineering is a particular field of Civil Engineering that evaluates the resistance of structures caused by wind loads. Bridges, high-rise buildings, chimneys and telecommunication towers might be susceptible to wind vibrations due to their increased flexibility, therefore a special design is carried for this aspect. Advancement in technology and scientific studies permit us doing research at small scale for more accurate analyses. Therefore scaled models of real structures are built and tested for various construction scenarios. These models are placed in wind tunnels where experiments are conducted to determine parameters such as: critical wind speeds for bridge decks, static wind coefficients and forces for buildings or bridges. The objective of the course was to offer insight to the students into the assessment of long-span cable-supported bridges and high-rise buildings under wind excitation. The participating students worked in interdisciplinary teams to increase their knowledge in the understanding and influences on the behaviour of wind-sensitive structures

Cultural heritage assets in Central Asia – Interdisciplinary approach to the complex problem of environmental risk assessment.

Uzbekistan owns more than 7,500 Cultural Heritage (CH) assets and the Republic of Tajikistan has registered a total of 2020 historical and cultural monuments including more than 300 architectural and more than 1000 archaeological sites. Several CH assets have been destroyed from constant negative influence of natural and man-made hazards. The governments have made considerable efforts to comply with its obligations under the UNESCO 1972 Convention. Both territories have a number of concepts for the preservation of architectural heritage. Whereas there is a lack of qualified engineers as well as review and consideration of international developments as well as international practice adoptable to Central Asia CH. This paper presents the findings of the partner’s investigations as well as the concept and objectives for the development of a master’s course in Cultural Heritage Conservation in Central Asia within Erasmus+CBHE project with focus on environmental risk assessment and mitigation (hydrogeology, climate changes, seismic action, etc.) on structures and natural places, documentation and monitoring strategies of structures and landscapes, restoration and conservation strategies and others

The characteristics of 2D and 3D modelling approach in calibration of reinforced concrete frames cyclic behaviour

A 3D FE micromodel of a bare RC frame was developed. The model is based on validated 2D micromodel. The 3D model obtained higher response when compared to its 2D counterpart. Consequently, a calibration of the frame was initiated. Calibration involved modifying parameters that govern the plastic behaviour of the computational model, such as fracture energy, plastic displacement and direction of plastic flow. It was shown that the greatest effect in lowering the response had the direction of plastic flow. Plastic flow direction was selected as -0.1 as it has greatest correlation with the experimental data. Negative value denotes that material volume will decrease due to crushing.publishe

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015

Comparative study of approaches for identification of passing trains from measurements

Tragwerke des Konstruktiven Ingenieurbaus sind in der Regel Unikate. Systematische Untersuchungen dienen daher dem Ziel, Umwelteinflüsse und Einwirkungen auf die Tragwerke und deren tatsächliches statisches und dynamisches Verhalten kurzzeitig und auch langfristig zu erfassen und zu verstehen. Im Rahmen des DFG-geförderten Graduiertenkollegs 1462 wurden drei vorgespannte Schleuderbetonmaste entlang der ICE-Neubaustrecke Erfurt–Leipzig mit verschiedenster Sensorik instrumentiert, um unter anderem das Verhalten der Maste während einer Zugvorbeifahrt zu untersuchen. Die Datenaufzeichnungen werden von Lichtschranken ausgelöst und erfolgen für einen definierten Zeitraum. Infolge von Störfaktoren und der Aufzeichnungslänge sind einerseits eine Vielzahl von Fehlmessungen und andererseits mehrere Zugvorbeifahrten in einem Datenfile zu verzeichnen. Somit sind in einem ersten Schritt die einzelnen Aufzeichnungen für die gezielte Auswertung des Einflusses der Zugvorbeifahrt auf das Verhalten der Oberleitungsmaste zu separieren. Dies erfolgt auch vor dem Hintergrund, dass die Bestimmung einer tatsächlichen Zugvorbeifahrt zukünftig nahezu fehlerfrei automatisiert erfolgen soll. Im Beitrag werden Methoden und erhobene Datensätze unterschiedlicher Sensorik zur Identifikation der Zugvorbeifahrten verglichen. Die Auswertung der gemessenen Daten des Erddrucksensors und der Beschleunigungsaufnehmer erfolgt mittels Techniken der Signalanalyse: Fast Fourier (FFT) und Gabor-Transformation.Civil engineering structures are mostly unique. Stochastic properties of acting loads and the corresponding structure reaction can be determined by help of long-term measurements. The identified loads and reactions can further be used in validation and assessment procedures to analyze static and dynamic behavior of the structure. Three reinforced concrete poles located along the new high-speed railway track Erfurt–Leipzig have been equipped with a monitoring system in the framework of the DFG founded Research Training Group 1462. The goal of the monitoring system is to identify influence of passing trains on the structural behavior of the poles. The measurement record is controlled by two photoelectric sensors. However, due to different disturbing factors fault detections of train passing are possible. Therefore, the obtained measurement data at first step must be classified with respect to actual train passing. Additionally, to simplify analysis of a huge amount of upcoming data, a classification algorithm should work automatically. In this paper, we present a comparative study of train identification methods based on tools of signal analysis compared to the identification based on the signals of photoelectric sensors. Especially, Fast Fourier Transform and Gabor Transform are applied to the time-history records from the soil pressure and acceleration sensors.publishe

On the use of climate models for estimating the non-stationary characteristic values of climatic actions in civil engineering practice

The characteristic values of climatic actions in current structural design codes are based on a specified probability of exceedance during the design working life of a structure. These values are traditionally determined from the past observation data under a stationary climate assumption. However, this assumption becomes invalid in the context of climate change, where the frequency and intensity of climatic extremes varies with respect to time. This paper presents a methodology to calculate the non-stationary characteristic values using state of the art climate model projections. The non-stationary characteristic values are calculated in compliance with the requirements of structural design codes by forming quasi-stationary windows of the entire bias-corrected climate model data. Three approaches for the calculation of non-stationary characteristic values considering the design working life of a structure are compared and their consequences on exceedance probability are discussed

Forecast Engineering: From Past Design to Future Decision 2018

Institute of Structural Engineering, Institute of Structural Mechanics, as well as Institute for Computing, Mathematics and Physics in Civil Engineering at the faculty of civil engineering at the Bauhaus-Universität Weimar presented special topics of structural engineering to highlight the broad spectrum of civil engineering in the field of modeling and simulation. The summer course sought to impart knowledge and to combine research with a practical context, through a challenging and demanding series of lectures, seminars and project work. Participating students were enabled to deal with advanced methods and its practical application. The extraordinary format of the interdisciplinary summer school offers the opportunity to study advanced developments of numerical methods and sophisticated modelling techniques in different disciplines of civil engineering for foreign and domestic students, which go far beyond traditional graduate courses. The proceedings at hand are the result from the Bauhaus Summer School course: Forecast Engineering held at the Bauhaus-Universität Weimar, 2018. It summarizes the results of the conducted project work, provides the abstracts/papers of the contributions by the participants, as well as impressions from the accompanying programme and organized cultural activities

Yığma yapıların deprem etkisi altında gözleme ve hesaba bağlı değerlendirilmesi için yöntem

Geleneksel kanıya göre donatısız yığma yapılar, kuvvetli deprem etkisine karş ı daha az dayanıklıdırlar. Ancak, bu binaların davranışını ifade edebilecek uygun modeller pek bulunmamaktadır. Orta Avrupa Standartlarına göre (EuroCode 8) sadece analitik yöntemlerle yapılan yığma binaların deprem davranışı çalışmaları, deprem sonrası yapılan hasar gözlemleriyle karşılaştırıldığında, hasar ilerlemesinin birinci şiddetten ikinci şiddete geçişinde çok fa zla kötümser sonuçlar vermediği yönündedir. Bu çalışmada, farklı analiz yöntemleri ve programlar kullanılarak yapılan analitik inceleme sonucu elde edilen verilere göre çok amaçlı yerinde aletsel test prosedürü uygulanmıştır. Ek olarak malzeme elemanları üzerinde laboratuvar testleri yapılarak yerel malzeme özellikleri de belirlenmiştir. İki boyutlu deneysel testlerin mevcut yapıların üç boyutlu kalitelerini belirlemede uygun olmadığından, doğrusal olmayan davranışı ifade etmek, hasar ilerlemesini ve duru mlarını belirlemek için büyük ölçekli üç boyutlu testler gerçekleştirilmiştir. Yığma yapılar için dijitalleştirilmiş veri tabanı oluşturulmasında deneyime bağlı veri , çok amaçlı yerinde bina instru me ntasyonu ve laboratuvar testlerinin analitik araştırmala rla etkileşimli olarak değerlendirilmesine dayanan yenilikçi bir yöntem geliştirilmiş ve önerilmiştir. Bu yaklaşım kullanılarak birçok bina incelenmiş ve kırılganlık eğrileri elde edilmiştir. Türetilen dijitalleştirilmiş veri tabanı, elde edilmiş kırılganl ık eğrileri ve farklı deprem senaryoları için elde edilen hasar tahminleri , başka ilgili kurumların (belediyeler, yığma yapı endüstrisi, sadece Türk değil farklı Avrupa ülkelerinin sorumlularının yönetmelik geliştirmesi) yeni projeler başlatmasına imkan sa ğlayabilecek niteliktedir.Unreinforced masonry is traditionally deemed to be less suitable for strong earthquake shaking, but appropriate models are missing to describe the behavio r of these building types. The pure analytical investiga tions to the earthquake behavio r of masonry buildings based on the new code standards in middle Europe (e.g. EC 8) leads to too pessimistic damage prognosis in the range of 1 to 2 intensity steps, which are in contra diction to the observed behavio r. A multi - tasking in - situ instrumental testing pr ocedure is carried out which in each phase is related to the outcome of parallel analytical investigation by using differ ent analysis methods and program mes. Additional aboratory tests on single material pieces are provided to determine the local material properties. Due to the fact, that the results from 2 - dimensional experimental tests are not appropriate to describe the 3 - dimensional quality of existing buildings, single large scale 3 - diminsional tests are conducted to describe the nonlinea r behavio r, damage progression and to identify damage cases. The innovative elements have to be seen in the generation of a database for digitized masonry structures and the combination between experienced data and multi - tasking instrumental in - situ and laboratory testing in their close interaction with the performed analytical investigations. Several buildings are investigated to obtain fragility curves by using this approach. In the frame of this study, the derived database for digitized masonry structures, the o btained fragility curves and damage prognosis for several earthquake scenarios may provides a starting point for further projects with probable interest groups (municipalities, masonry industry, not only Turkish, but also some responsible persons for code development of different European countries)