Inst. Bauingenieurwesen

123 Items

Recent Submissions
Decision making in structural engineering problems under polymorphic uncertainty

Petryna, Yuri ; Drieschner, Martin (2019-02-22)

The treatment of diverse uncertainties is an important challenge in structural engineering problems, especially from the viewpoint of realistic analysis. Inaccuracy and variability are always present and have to be quantified by either probabilistic, possibilistic, polymorphic or other uncertainty approaches. Regardless to the applied uncertainty quantification method, the numerical predictions...

Parameterization of arbitrary hole shapes using non-destructive testing and resulting stress concentration in a 2D plate with finite dimensions

Drieschner, Martin ; Petryna, Yuri ; Eichner, Lukas (2019-02-21)

Air void inclusions are mostly unavoidable in many different materials resulting from manufacturing processes or environmental conditions. In this contribution, non-destructive testing (NDT) like computer tomography (CT) is used for air void detection and quantification. The air voids lead to stress concentrations around them which influence significantly the structural integrity and at worst, ...

Acquisition of polymorphic uncertain data based on computer tomographic scans and integration in numerical models of adhesive bonds

Drieschner, Martin ; Petryna, Yuri (2019-02-21)

Since commercial wind turbines were introduced around 1980, the length of rotor blades has increased substantially up to 80m with consequently higher demands on availability and failure prevention. One of the typical failure mechanisms of rotor blades in operation are fatigue cracks in adhesive bonds often caused by air voids with a-priori unknown properties, which results from the manufacturi...

Electronic Supplementary to Doctoral Dissertation

Lobanova, Anastasia (2018)

This Electronic Supplementary contains the SWIM Model set up, calibrated and validated for all eight river basins, together with executables, used to perform modelling experiments for Doctoral Thesis "The assessment of hydrological impacts of climate change and their implications for water management: from the local to European scale"

Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications

Zhou, Kuangxin ; Stüber, Johan ; Schubert, Rabea-Luisa ; Kabbe, Christian ; Barjenbuch, Matthias (2017)

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the...

Towards time- and state-dependent seismic risk over urban scales

Haas, Michael (2019)

Probabilistic seismic risk assessment involves the appraisal of three components: the seismic hazard due to expected ground motions, the exposure, i.e., assets exposed to the hazard, and their vulnerability with respect to the hazard. Earthquake sequences are a result of a time dependent process, which is complex to consider in a probabilistic framework. It is thus common to reduce sequences to...

Phosphorus recovery from municipal and fertilizer wastewater: China's potential and perspective

Zhou, Kuangxin ; Barjenbruch, Matthias ; Kabbe, Christian ; Inial, Goulven ; Remy, Christian (2017)

Phosphorus (P) is a limited resource, which can neither be synthesized nor substituted in its essential functions as nutrient. Currently explored and economically feasible global reserves may be depleted within generations. China is the largest phosphate fertilizer producing and consuming country in the world. China's municipal wastewater contains up to 293,163 Mg year of phosphorus, which equa...

Comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex® systems

Zhou, Kuangxin ; Remy, C. ; Kabbe, C. ; Barjenbruch, M. (2018)

Phosphorus (P) recovery through struvite is already both technically and economically feasible. This has been proved by more than 40 large-scale plants worldwide. However, when designing and implementing these P-recovery technologies, the environmental effects need to be considered. Therefore, a comparative environmental life cycle assessment of phosphorus recovery with different generations of...

Unterraumbasierte Detektion von Strukturschäden an Jacket-Gründungen von Offshore-Windenergieanlagen

Hille, Falk (2018)

Die vorliegende Arbeit beschreibt die Adaption eines globalen, schwingungsbasierten Verfahrens zur frühzeitigen Erkennung von Strukturschäden an Gründungsstrukturen offshore installierter Windenergieanlagen (OWEA). Damit soll es Betreibern von Offshore-Windparks ermöglicht werden, im Rahmen periodisch durchgeführter messtechnischer Überwachungsmaßnahmen mit einem gegenüber wiederkehrender Inspe...

Bitumen und Chemometrie

Weigel, Sandra (2018)

Im Rahmen dieser Arbeit konnte gezeigt werden, dass mithilfe der Fourier-Transformations-Infrarotspektroskopie und der Anwendung multivariater Analysemethoden eine umfassende Charakterisierung von Bitumenproben möglich ist. Als Grundlage dienten 90 Straßenbaubitumen unterschiedlicher Herkunft, Alterungsstufe und Sorte, die mithilfe verschiedener chemischer und physikalischer Verfahren untersuch...

Simulations of nutrient emissions from a net cage aquaculture system in a Brazilian bay

Matta, Elena ; Selge, Florian ; Gunkel, Günter ; Rossiter, Karina ; Jourieh, Ayman ; Hinkelmann, Reinhard (2016)

Hydrodynamics and transport simulations were conducted with the modeling software TELEMAC-2D on Icó-Mandantes bay, a branch of the Itaparica reservoir. The bay has a maximal operational water level amplitude of 5 m and is suffering from eutrophication and algae bloom. Therefore, we investigated low and high water level scenarios with two different high resolution meshes, with the purpose to dee...

An ALE method for penetration into sand utilizing optimization-based mesh motion

Aubram, Daniel ; Rackwitz, Frank ; Wriggers, Peter ; Savidis, Stavros A. (2015)

The numerical simulation of penetration into sand is one of the most challenging problems in computational geomechanics. The paper presents an arbitrary Lagrangian–Eulerian (ALE) finite element method for plane and axisymmetric quasi-static penetration into sand which overcomes the problems associated with the classical approaches. An operator-split is applied which breaks up solution of the go...

A comparison of different seismological and geotechnical parameters for site characterization

Boxberger, Tobias (2018)

The geometry of the subsoil structure, the soil types involved and the variation in their properties with depth, lateral discontinuities and surface topography are causes of lateral variation in earthquake-induced ground motion, over relatively small scales, referred to as "site effects" The modification of ground motion can manifest itself through amplification at particular frequencies (the ...

Homogeneous equilibrium model for geomechanical multi-material flow with compressible constituents

Aubram, Daniel (2016-04-09)

Multi-material flow generally describes a situation where several distinct materials separated by sharp material interfaces undergo large deformations. In order to model such flow situations in the context of geomechanics and geotechnical engineering, a theoretical framework is presented which introduces a possible two-phase coupled saturated granular material behavior among the different mater...

Nichtummantelte Sandsäulen in weichen Böden mit hohem organischen Anteil

Ney, Marcel (2018)

In der vorliegenden Arbeit wurden 20 klein- als auch großmaßstäbliche Modellversuche durchgeführt. Deren Ergebnisse wurden für einen Modifikationsansatz eines analytischen Bemessungsverfahrens genutzt. Es konnte nachgewiesen werden, dass unter Laborbedingungen kein Ausbauchen nichtummantelter Sandsäulen stattfindet. Es wurden wesentliche praxisrelevante Parameter variiert und deren Einflussauf ...

Urban flood modeling using shallow water equations with depth-dependent anisotropic porosity

Özgen, Ilhan ; Zhao, Jiaheng ; Liang, Dongfang ; Hinkelmann, Reinhard (2016)

The shallow water model with anisotropic porosity conceptually takes into account the unresolved subgrid-scale features, e.g. microtopography or buildings. This enables computationally efficient simulations that can be run on coarser grids, whereas reasonable accuracy is maintained via the introduction of porosity. This article presents a novel numerical model for the depth-averaged equations w...

Shallow water equations with depth-dependent anisotropic porosity for subgrid-scale topography

Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2016)

This paper derives a novel formulation of the depth-averaged shallow water equations with anisotropic porosity for computational efficiency reasons. The aim is to run simulations on coarser grids while maintaining an acceptable accuracy through the introduction of porosity terms, which account for subgrid-scale effects. The porosity is divided into volumetric and areal porosities, which are ass...

Upscaling the shallow water model with a novel roughness formulation

Özgen, Ilhan ; Teuber, Katharina ; Simons, Franz ; Liang, Dongfang ; Hinkelmann, Reinhard (2015-08)

This study presents a novel roughness formulation to conceptually account for microtopography and compares it to four existing roughness models from literature. The aim is to increase the grid size for computational efficiency, while capturing subgrid scale effects with the roughness formulation to prevent the loss in accuracy associated with coarse grids. All roughness approaches are implement...

The influence of nanomaterials on the thermal resistance of cement-based composites – a review

Pawel, Sikora ; Abd Elrahman, Mohamed ; Stephan, Dietmar (2018-06-26)

Exposure to elevated temperatures has detrimental effects on the properties of cementitious composites, leading to irreversible changes, up to total failure. Various methods have been used to suppress the deterioration of concrete under elevated temperature conditions. Recently, nanomaterials have been introduced as admixtures, which decrease the thermal degradation of cement-based composites a...

Conceptual simplifications for long-term sediment transport simulations

Zhang, Qing (2018)

The aim of this PhD thesis is to assess the long-term evolution of the fine sediment budget in the Iffezheim reservoir, which is the last barrage of the impounded section of the Rhine River. Based on the observed flow and suspended sediment concentration as well as echo-sounding data, various methods were proposed to estimate long-term riverbed changes. The application of a high-resolution 3D m...