@article{TalebiSilaniBordasetal., author = {Talebi, Hossein and Silani, Mohammad and Bordas, St{\´e}phane Pierre Alain and Kerfriden, Pierre and Rabczuk, Timon}, title = {A computational library for multiscale modeling of material failure}, series = {Computational Mechanics}, journal = {Computational Mechanics}, abstract = {A computational library for multiscale modeling of material failure}, subject = {Angewandte Mathematik}, language = {en} } @article{SilaniZiaeiRadTalebietal., author = {Silani, Mohammad and Ziaei-Rad, S. and Talebi, Hossein and Rabczuk, Timon}, title = {A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, abstract = {A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites}, subject = {Angewandte Mathematik}, language = {en} } @phdthesis{Nowottny, author = {Nowottny, Vera}, title = {Die Camera Obscura als Kondensationsmobil : Der Weg von der formalen {\"A}sthetik in der Fotografie bis hin zum k{\"u}nstlerischen Akt des Atmens}, doi = {10.25643/bauhaus-universitaet.2312}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20141014-23123}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {143}, abstract = {{\"U}ber die formale {\"A}sthetik der Aufl{\"o}sung in der Fotografie bis hin zum k{\"u}nstlerischen Akt des Atmens}, subject = {Camera Obscura}, language = {de} } @article{NguyenXuanNguyenBordasetal., author = {Nguyen-Xuan, Hung and Nguyen, Hiep Vinh and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon and Duflot, Marc}, title = {A cell-based smoothed finite element method for three dimensional solid structures}, series = {KSCE Journal of Civil Engineering}, journal = {KSCE Journal of Civil Engineering}, doi = {10.1007/s12205-012-1515-7}, pages = {1230 -- 1242}, abstract = {This paper extends further the strain smoothing technique in finite elements to 8-noded hexahedral elements (CS-FEM-H8). The idea behind the present method is similar to the cell-based smoothed 4-noded quadrilateral finite elements (CS-FEM-Q4). In CSFEM, the smoothing domains are created based on elements, and each element can be further subdivided into 1 or several smoothing cells. It is observed that: 1) The CS-FEM using a single smoothing cell can produce higher stress accuracy, but insufficient rank and poor displacement accuracy; 2) The CS-FEM using several smoothing cells has proper rank, good displacement accuracy, but lower stress accuracy, especially for nearly incompressible and bending dominant problems. We therefore propose 1) an extension of strain smoothing to 8-noded hexahedral elements and 2) an alternative CS-FEM form, which associates the single smoothing cell issue with multi-smoothing cell one via a stabilization technique. Several numerical examples are provided to show the reliability and accuracy of the present formulation.}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenThoiRabczukLamPhatetal., author = {Nguyen-Thoi, T. and Rabczuk, Timon and Lam-Phat, T. and Ho-Huu, V. and Phung-Van, P.}, title = {Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3)}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, abstract = {Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3)}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenThanhMuthuZhuangetal., author = {Nguyen-Thanh, Nhon and Muthu, Jacob and Zhuang, Xiaoying and Rabczuk, Timon}, title = {An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics}, series = {Computational Mechanics}, journal = {Computational Mechanics}, pages = {369 -- 385}, abstract = {An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenKerfridenBordasetal., author = {Nguyen, V.P. and Kerfriden, Pierre and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon}, title = {Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm}, series = {Computer-Aided Design}, journal = {Computer-Aided Design}, abstract = {Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm}, subject = {Angewandte Mathematik}, language = {en} } @phdthesis{Nayono, author = {Nayono, Suwartanti}, title = {Development of a Sustainability-based Sanitation Planning Tool (SusTA) for Developing Countries}, doi = {10.25643/bauhaus-universitaet.2222}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20140619-22227}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {153; mit Anh{\"a}ngen 209}, abstract = {Background and Research Goal Despite all the efforts in the sanitation sector, it is acknowledged that the world is not on track to meet the MDG sanitation target to reduce the number of people without access to sanitation by 2015. Furthermore, a large number of existing sanitation facilities in developing countries is out of order. This leads to the conclusion that, besides technical failures, the planning process in the sanitation sector was ineffective. This ineffectiveness may be attributed to the lack of knowledge of the sanitation planners about the local conditions of the sanitation project. In addition, sustainability of a technology is often approached from a fragmented perspective that often leads to an unsustainable solution. The dissertation is conducted within the framework of the Integrated Water Resources Management (IWRM) Indonesia project. The goal of this work is to contribute to the development of a methodology of a planning tool for sustainable sanitation technology. The tool is designed for sanitation planners in developing countries, where a top-down planning approach is common practice. The proposed tool enables comprehensive sustainability assessments (using the Helmholtz Concept of Sustainability as reference), taking into account local conditions. State of the Science In the planning practice, many sanitation planning tools focus on technology selection. However, it has become evident that the selection criteria for sustainable technologies are not always considered in the tools' framework. In other cases, when the criteria are provided by the tool, there is no clear indication of the conditions to be fulfilled in order to meet these criteria. Specifically, there is no reference to what is meant by sustainable technology in a particular context and how to comprehensively assess the sustainability of different technology options. Research Methodology Developing a planning tool is an empirical process, combining theory and practical experience. Hence, the development process of such a tool requires extensive observations, particularly on the interaction between stakeholders in the sanitation sector as well as between technology and its environment. For this purpose, a case study within the project area was carried out. Pucanganom, a village representing common strategic problems in developing countries (e.g. top-down planning approaches, lack of involvement of beneficiaries in the planning process, lack of sustainability assessments) was finally selected as the case study area. After the in-depth case study, an analytical generalisation was developed to enable the tool's application to a broader context. Results The result of this research is a new tool - the Sustainability-based Sanitation Planning Tool (SusTA). SusTA enables comprehensive sustainability assessment in its five generic steps, namely: (1) analysis of stakeholders and sanitation policy in the region, (2) distance-to-target analysis on sanitation conditions in the region, (3) examination of physical and socio-economic conditions in the project area, (4) contextualisation of the technology assessment process in the project area, and (5) sustainability-oriented technology assessment at the project level. These steps are conducted at two levels of planning - the region and the project area - in order to identify the specific problems and interests which influence the selection of a sanitation system. Each planning step is equipped with tool elements (e.g. set of indicators, household questionnaires, technology assessment matrices) to support the analysis. From the development of SusTA, it can be concluded that four elements are required for an effective and widely applicable sanitation planning tool: sustainability concept, participatory approach, contextualisation framework and modification framework. SusTA provides both a theoretical and a practical basis for assessing the sustainability of sanitation technologies in developing countries. The tool's main advantages for decision makers in these countries are: It is simple and transparent in its steps, does not require vast amounts of data and does not need a sophisticated computer program.}, subject = {sanitation planning, sustainable technology, sustainability assessment}, language = {en} } @article{NanthakumarLahmerRabczuk, author = {Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon}, title = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets}, series = {Computer Methods in Applied Mechanics and Engineering}, journal = {Computer Methods in Applied Mechanics and Engineering}, pages = {98 -- 112}, abstract = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets}, subject = {Angewandte Mathematik}, language = {en} } @article{NagelSimonKuemmeletal., author = {Nagel, Falk and Simon, Flaviu and K{\"u}mmel, Benjamin and Bergmann, Jean Pierre and Hildebrand, J{\"o}rg}, title = {Optimization Strategies for Laser Welding High Alloy Steel Sheets}, series = {Physics Procedia}, journal = {Physics Procedia}, doi = {10.1016/j.phpro.2014.08.040}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31554}, pages = {1242 -- 1251}, abstract = {A known phenomenon during laser welding of thin sheets is the deformation caused by thermally induced stresses. This deformation can result in a change of the gap width between the welded parts, which leads to an unstable welding process. Inducing displacements by using a second heat source will compensate for the change in gap width, hence optimizing the welding process. The base material is 1 mm thick austenitic stainless steel 1.4301, which is welded by a CO2 laser. The second heat source is a diode laser. The gap between the welded parts was set between 0.05 mm and 0.1 mm. The influence of the second heat source on the welding process and the welding result is described. The usage of a second heat source allows a higher gap width to be set prior to the welding process. The results of the numerical simulation were found to be corresponding to those of the experiments.}, subject = {Edelstahl}, language = {en} } @article{MotraHildebrandDimmigOsburg, author = {Motra, Hem Bahadur and Hildebrand, J{\"o}rg and Dimmig-Osburg, Andrea}, title = {Assessment of strain measurement techniques to characterise mechanical properties of structural steel}, series = {Engineering Science and Technology, an International Journal}, journal = {Engineering Science and Technology, an International Journal}, doi = {10.1016/j.jestch.2014.07.006}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31540}, pages = {260 -- 269}, abstract = {Strain measurement is important in mechanical testing. A wide variety of techniques exists for measuring strain in the tensile test; namely the strain gauge, extensometer, stress and strain determined by machine crosshead motion, Geometric Moire technique, optical strain measurement techniques and others. Each technique has its own advantages and disadvantages. The purpose of this study is to quantitatively compare the strain measurement techniques. To carry out the tensile test experiments for S 235, sixty samples were cut from the web of the I-profile in longitudinal and transverse directions in four different dimensions. The geometry of samples are analysed by 3D scanner and vernier caliper. In addition, the strain values were determined by using strain gauge, extensometer and machine crosshead motion. Three techniques of strain measurement are compared in quantitative manner based on the calculation of mechanical properties (modulus of elasticity, yield strength, tensile strength, percentage elongation at maximum force) of structural steel. A statistical information was used for evaluating the results. It is seen that the extensometer and strain gauge provided reliable data, however the extensometer offers several advantages over the strain gauge and crosshead motion for testing structural steel in tension. Furthermore, estimation of measurement uncertainty is presented for the basic material parameters extracted through strain measurement.}, subject = {Baustahl}, language = {en} } @article{Massaretti, author = {Massaretti, Pier Giorgio}, title = {Dagli inizi dell'urbanismo teorico alla citt{\`a} moderna. Visioni urbanistiche del totalitarismo - Italia}, series = {Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne}, journal = {Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne}, doi = {10.25643/bauhaus-universitaet.3222}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170529-32228}, pages = {1 -- 45}, abstract = {La prima edizione di questo testo {\`e} apparsa, in tedesco, nel volume II.2.: Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne, a cura di Vittorio Magnago Lampugnani, Katia Frey, Eliana Perotti, con il sostegno di Departement Architektur der Eidgen{\"o}ssischen Technischen Hochschule, Z{\"u}rich (Gebr. Mann Verlag, Berlin 2014, pp. 1307-1390). Previ specifici accordi con l'editore, viene qui presentata la versione originaria, in italiano, dell'intero capitolo: Modernit{\"a}t und Emphase. St{\"a}dtebau im italienischen Faschismus, e comprendente: i) una capiente saggio introduttivo - in una versione pi{\`u} ampia ed articolata (comprensiva della "Bibliografia sistematica", di riferimento) del testo in tedesco; ii) la versione in italiano del repertorio antologico di riferimento - e comprensiva di una "Scheda introduttiva", sull'Autore-Opera, e di una selezione del testo in esame.}, subject = {St{\"a}dtebau}, language = {it} } @inproceedings{Massaretti, author = {Massaretti, Pier Giorgio}, title = {La ri-fondazione della Libia balbiana (1933-1939). Il poderoso racconto fotografico dei "Ventimila"}, series = {Citt{\`a} mediterranee in trasformazione}, booktitle = {Citt{\`a} mediterranee in trasformazione}, doi = {10.25643/bauhaus-universitaet.3223}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170529-32234}, pages = {14}, abstract = {La prima edizione di questo testo {\`e} apparsa negli atti del VI Convegno Internazionale di Studi del CIRICE - Centro Interdipartimentale di Ricerca sull'Iconografia della Citt{\`a} Europea - Universit{\`a} di Napoli Federico II, (Napoli, 13-15 marzo 2014), dal titolo: Citt{\`a} mediterranee in trasformazione. Identit{\`a} e immagine del paesaggio urbano tra Sette e Novecento, a cura di A. Buccaro e C. de Seta (Collana: Polis, 6; Napoli: Edizioni Scientifiche Italiane, 2014; pp. 1216; ISBN 9788849528145), all'interno della sessione 7, Le trasformazioni del paesaggio urbano nella fotografia e nella cinematografia, coordinatori: F. Capano, M. Iuliano, pp. 1085-1098. Il Convegno, aperto a studiosi di ambito nazionale e internazionale, si poneva l'obiettivo di fare il punto sulla storiografia riguardante la citt{\`a} mediterranea in et{\`a} contemporanea, con particolare riferimento alla sua identit{\`a}, struttura e immagine, dall'inizio dell'industrializzazione all'et{\`a} post-illuminista e borghese, fino ai temi inerenti l'evoluzione/involuzione del territorio e del paesaggio post-industriale, nonch{\´e} lo sviluppo del modello turistico tra Otto e Novecento.}, subject = {St{\"a}dtebau}, language = {it} } @article{MasoodKharalNasir, author = {Masood, R. and Kharal, M. K. N. and Nasir, A.R.}, title = {Is BIM Adoption Advantageous for Construction Industry of Pakistan?}, series = {Procedia Engineering}, journal = {Procedia Engineering}, doi = {10.1016/j.proeng.2014.07.021}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31509}, pages = {229 -- 238}, abstract = {Lack of Information technology applications on construction projects lead to complex flow of data during project life cycle. Building Information Modeling (BIM) has gained attention in the Architectural, Engineering and Construction (AEC) industry, envisage the use of virtual n-dimensional (n-D) models to identify potential conflicts in design, construction or operational of any facility. A questionnaire has been designed to investigate perceptions regarding BIM advantages. Around 102 valid responses received from diversified stakeholders. Results showed very low BIM adoption with low level of 'Buzz'. BIM is a faster and more effective method for designing and construction management, it improves quality of the design and construction and reduces rework during construction; which came out as the top thee advantages according to the perception of AEC professionals of Pakistan.BIM has least impact on reduction of cost, time and human resources. This research is a bench mark study to understand adoption and advantageous of BIM in Pakistan Construction Industry.}, subject = {Building Information Modeling}, language = {en} } @inproceedings{MarzbanAlmasiSchwarz, author = {Marzban, Samira and Almasi, Ashkan and Schwarz, Jochen}, title = {REINFORCED CONCRETE STRUCTURAL WALL DATABASE DEVELOPMENT FOR MODEL VALIDATION}, doi = {10.25643/bauhaus-universitaet.2452}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20150831-24523}, abstract = {Reinforced concrete walls are commonly selected as the lateral resisting systems in seismic design of buildings. The design procedure requires reliable/robust models to predict the wall response. Many researchers, thus, have focused on using the available experimental data to be able to comment on the quality of models at hand. What is missing though is an uncertain attitude towards the experimental data since such data can be affected by different sources of uncertainty. In this paper, we introduce the database created for model quality evaluation purposes considering the uncertainties in the experimental data. This is the first step of a larger study on experience-based model quality evaluation of reinforced concrete walls. Here, we briefly present the database as well as six sample validations of the developed numerical model (the quality of which is to be assessed). The database contains the information on nearly 300 wall specimens from about 50 sources. Both the database and the numerical model, built for uncertainty/sensitivity analysis purposes, are mainly based on ten parameters. These include geometry, material, reinforcement layout and loading properties. The validation results prove that the model is able to predict the wall response satisfactorily. Consequently, the validated numerical model could be used in further quality evaluation studies.}, subject = {Baustoff}, language = {en} } @phdthesis{Mai, author = {Mai, Luu}, title = {Structural Control Systems in High-speed Railway Bridges}, issn = {1610-7381}, doi = {10.25643/bauhaus-universitaet.2339}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20141223-23391}, school = {Bauhaus-Universit{\"a}t Weimar}, pages = {147}, abstract = {Structural vibration control of high-speed railway bridges using tuned mass dampers, semi-active tuned mass dampers, fluid viscous dampers and magnetorheological dampers to reduce resonant structural vibrations is studied. In this work, the addressed main issues include modeling of the dynamic interaction of the structures, optimization of the parameters of the dampers and comparison of their efficiency. A new approach to optimize multiple tuned mass damper systems on an uncertain model is proposed based on the H-infinity optimization criteria and the DK iteration procedure with norm-bounded uncertainties in frequency domain. The parameters of tuned mass dampers are optimized directly and simultaneously on different modes contributing significantly to the multi-resonant peaks to explore the different possible combinations of parameters. The effectiveness of the present method is also evaluated through comparison with a previous method. In the case of semi-active tuned mass dampers, an optimization algorithm is derived to control the magnetorheological damper in these semi-active damping systems. The use of the proposed algorithm can generate various combinations of control gains and state variables. This can lead to the improvement of the ability of MR dampers to track the desired control forces. An uncertain model to reduce detuning effects is also considered in this work. Next, for fluid viscous dampers, in order to tune the optimal parameters of fluid viscous dampers to the vicinity of the exact values, analytical formulae which can include structural damping are developed based on the perturbation method. The proposed formulae can also be considered as an improvement of the previous analytical formulae, especially for bridge beams with large structural damping. Finally, a new combination of magnetorheological dampers and a double-beam system to improve the performance of the primary structure vibration is proposed. An algorithm to control magnetorheological dampers in this system is developed by using standard linear matrix inequality techniques. Weight functions as a loop shaping procedure are also introduced in the feedback controllers to improve the tracking ability of magnetorheological damping forces. To this end, the effectiveness of magnetorheological dampers controlled by the proposed scheme, along with the effects of the uncertain and time-delay parameters on the models, are evaluated through numerical simulations. Additionally, a comparison of the dampers based on their performance is also considered in this work.}, subject = {High-speed railway bridge}, language = {en} } @article{LuuMartinezRodrigoZabeletal., author = {Luu, M. and Martinez-Rodrigo, M.D. and Zabel, Volkmar and K{\"o}nke, Carsten}, title = {H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges}, series = {Journal of Sound and Vibration}, journal = {Journal of Sound and Vibration}, pages = {2421 -- 2442}, abstract = {H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges}, subject = {Angewandte Mathematik}, language = {en} } @article{LinnowNiermannBonatzetal., author = {Linnow, Kirsten and Niermann, Michael and Bonatz, Dennis and Posern, Konrad and Steiger, Michael}, title = {Experimental Studies of the Mechanism and Kinetics of Hydration Reactions}, series = {Energy Procedia}, journal = {Energy Procedia}, doi = {10.1016/j.egypro.2014.02.046}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31484}, pages = {394 -- 404}, abstract = {The mechanism and the kinetics of hydration reactions are important for the application of a salt hydrate as a thermochemical heat storage material. MgSO4·H2O and Na2SO4 were chosen in this study because they are both promising candidates for such an application. Considering that the hydration of these salts yields MgSO4·7H2O and Na2SO4·10H2O as the reaction products, the maximum overall heat effect can be calculated from the heat of condensation of water vapor (44 kJ mol-1) and the heats of hydration of 75 kJ·mol-1 (for MgSO4·H2O) and 81 kJ mol-1 (for Na2SO4). Based on the densities of the two hydrated phases, this results in the very high theoretical energy densities of 2.3 GJ·m-3 and 2.4 GJ·m-3, respectively, for MgSO4·7H2O and Na2SO4·10H2O. Not only the energy density is important for the dimensioning of a storage system, but also the kinetics of hydration reactions play a major role for the application as storage material. In the present study, hydration reactions under varying climatic conditions were investigated by using water vapor sorption measurements and in-situ Raman microscopy. Using the phase diagrams, it can be clearly shown that the mechanism and the kinetics depend on the climatic conditions. Below the deliquescence humidity of the lower hydrated phase the hydration proceeds as solid state reaction, whilst above the deliquescence humidity a through solution mechanism takes place.}, subject = {W{\"a}rmespeicherung}, language = {en} } @article{LeNguyenLudwig, author = {Le, Ha Thanh and Nguyen, Sang Thanh and Ludwig, Horst-Michael}, title = {A Study on High Performance Fine-Grained Concrete Containing Rice Husk Ash}, series = {International Journal of Concrete Structures and Materials}, journal = {International Journal of Concrete Structures and Materials}, doi = {10.1007/s40069-014-0078-z}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31477}, pages = {301 -- 307}, abstract = {Rice husk ash (RHA) is classified as a highly reactive pozzolan. It has a very high silica content similar to that of silica fume (SF). Using less-expensive and locally available RHA as a mineral admixture in concrete brings ample benefits to the costs, the technical properties of concrete as well as to the environment. An experimental study of the effect of RHA blending on workability, strength and durability of high performance fine-grained concrete (HPFGC) is presented. The results show that the addition of RHA to HPFGC improved significantly compressive strength, splitting tensile strength and chloride penetration resistance. Interestingly, the ratio of compressive strength to splitting tensile strength of HPFGC was lower than that of ordinary concrete, especially for the concrete made with 20 \% RHA. Compressive strength and splitting tensile strength of HPFGC containing RHA was similar and slightly higher, respectively, than for HPFGC containing SF. Chloride penetration resistance of HPFGC containing 10-15 \% RHA was comparable with that of HPFGC containing 10 \% SF.}, subject = {Hochfester Beton}, language = {en} } @techreport{KoenigTapiasSchmitt, author = {K{\"o}nig, Reinhard and Tapias, Estefania and Schmitt, Gerhard}, title = {New Methods in Urban Analysis and Simulation: Documentation of the teaching results from the spring semester 2014}, doi = {10.25643/bauhaus-universitaet.2515}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20160121-25154}, pages = {62}, abstract = {Documentation of the teaching results from the spring semester 2014 at ETH Zurich}, subject = {St{\"a}dtebau}, language = {en} }