7.2 Ingenieurbau
Filtern
Erscheinungsjahr
- 2018 (29) (entfernen)
Dokumenttyp
- Vortrag (29) (entfernen)
Referierte Publikation
- nein (29) (entfernen)
Schlagworte
- Fatigue (2)
- Repair (2)
- SHM (2)
- Slab track (2)
- Acoustic emission testing (1)
- Amplitude-charge weight laws (1)
- Amplitude-distance laws (1)
- Analysis of variance (1)
- Ballast track (1)
- Bauwerk-Boden-Wechselwirkung (1)
- Bayes'sche Analyse (1)
- Big Data (1)
- Boundary element method (1)
- Box-Behnken (1)
- Brücken (1)
- Compaction Grouting (1)
- Compressive cyclic loading (1)
- Compressive strength (1)
- Crack repair (1)
- Cracks (1)
- Cyclic axial shearing (1)
- DEM-LBM simulation (1)
- DUCON® (1)
- Datenmanagement (1)
- Deckenschwingungen (1)
- Design (1)
- Design methods (1)
- Design practice (1)
- Digital Image Correlation (1)
- Dispersionsmessung (1)
- Ductility (1)
- E-modulus (1)
- Elastische Gebäudelagerung (1)
- Energy (1)
- Environmental (1)
- Ermüdungsschäden (1)
- Erosion of cohesive soils (1)
- Erschütterungsprognose (1)
- Explosion-induced ground vibrations (1)
- Fault detection (1)
- GPU parallelisation (1)
- Geomechanics (1)
- Geomechanics of offshore foundations (1)
- Ground vibration measurements (1)
- Grout (1)
- Grout Injection (1)
- Grouted Connection (1)
- Grouting (1)
- Hammer impact (1)
- High-strength concrete (1)
- Impact (1)
- Inspection planning (1)
- Interface model (1)
- Jet erosion test (1)
- Load bearing behaviour (1)
- Material Point Method (1)
- Micro-reinforcement (1)
- Microfine cement (1)
- Micromechanical LBM-DEM simulation (1)
- Mix design (1)
- Mobile elements (1)
- Monitoring (1)
- Non-destructive testing (1)
- Numerical model (1)
- Numerical modeling (1)
- Offshore (1)
- Offshore Pile Foundation (1)
- Offshore pile foundations (1)
- Offshore wind energy (1)
- Offshore wind farms (1)
- Offshore-Wind (1)
- Offshore-Windenergieanlagen (1)
- Physical phenomenology (1)
- Pile Capacity (1)
- Pile foundations (1)
- Prediction of explosion induced ground and building vibration (1)
- Probabilitische Ingenieurmodelle (1)
- Quasi-static and dynamic tests (1)
- Randelementmethode (1)
- Rechenmodelle (1)
- Rehabilitation (1)
- Reliability (1)
- Residual evaluation (1)
- Risiko (1)
- Risikoanalyse (1)
- Risk (1)
- Risslumineszenz (1)
- Schadensdetektion (1)
- Schwingungsbasierte Verfahren (1)
- Shrinkage (1)
- Size effect (1)
- Slenderness effect (1)
- Soil erosion (1)
- Soil properties (1)
- Statistical tests (1)
- Steel structures (1)
- Stereo photogrammetry (1)
- Structural Health Monitoring (1)
- Supplementary cementitious materials (1)
- TOP (1)
- Track damage (1)
- Train configuration (1)
- Train passage (1)
- Train passages (1)
- Tran speed (1)
- UHPC (1)
- Ultrasonic testing (1)
- Uncertainty in reference (1)
- Unterraummethoden (1)
- Vibration measurement (1)
- Wave-Tower interaction (1)
- Wellenfeldberechnung (1)
- Windenergie (1)
- Windfarm wake analysis (1)
- Zivile Sicherheit (1)
Organisationseinheit der BAM
- 7.2 Ingenieurbau (29) (entfernen)
Eingeladener Vortrag
- nein (29)
The response of many geotechnical systems, whose structural behavior depends on shearing effect, is closely related to soil structure interaction phenomenon. Experimentally it is found that the localisation of these effect happens at a narrow soil layer next to the structure. Numerically, this behavior can be modelled through interface elements and adequate constitutive models. In this work, a constitutive model in the framework of Generalized Plasticity for sandy soils has been chosen to be adapted for the interface zone.
From the direct shear experiments a sandy soil at loose and dense states under different normal pressures is considered. The adapted constitutive model is able to reproduce contraction and dilatation of the soil according to its relative density and it shows a good agreement with the experimental data.
Risslumineszenz
(2018)
Unterraumbasierte Detektion von Strukturschäden an Jacket-Gründungen von Offshore-Windenergieanlagen
(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 Inspektionen wesentlich geringen Aufwand auftretende Schäden an der Struktur zuverlässig zu delektieren.
Das untersuchte und implementierte Verfahren basiert auf der Methode der stochastischen unterraumbasierten Schadensdetektion. Dabei erfolgt eine statistische Analyse des wiederkehrend messtechnisch aufgenommenen dynamischen Antwortverhaltens des mechanischen Systems. Mittels statistischem Test werden signifikante Änderungen in dessen Eigenstruktur und damit Schäden delektiert.
Im Rahmen der vorliegenden Arbeit wurden umfangreiche experimentelle als auch numerische Untersuchungen zur Sensitivität und Robustheit des beschriebenen Schadensindikators durchgeführt. Dazu sind zunächst an einem Labormodell mittels künstlich und reversibel eingebrachter Schäden grundlegende Analysen zu den Einflüssen signal- und verfahrensinhärenter Kenngrößen durchgeführt worden. Auf der Basis dieser Ergebnisse wurde im Anschluss mittels numerischer Analysen das Antwortverhalten von OWEA simuliert und der entwickelte Algorithmus zur Schadensdetektion an den so realisierten Datensätzen angewendet.
Anhand der Ergebnisse der Arbeit wird aufgezeigt, dass, vorausgesetzt die Windenergieanlage befindet sich in Parkposition, eine Detektion von schon geringen Schäden an Gründungs-strukturen mit dem beschriebenen Verfahren, auch unter Einsatz weniger Messaufnehmer, zuverlässig möglich ist.
Within the presented research project, experimental and numerical investigations were performed to develop a thin-shelled, modular, mobile element system made of a micro-reinforced ultra-high-performance ductile concrete (DUCON®). Material parameters were experimentally determined to adapt the material model within the numerical analysis applying the Drucker-Prager relationship. Afterwards, for validation of the numerical models, quasi-static and high-velocity impact tests were performed on plate-like structures. Finally, a suitable geometry of transportable barrier elements will be designed, which provides a maximum of resistance against impact by a minimum of weight and a maximum of mobility.
Mit der Errichtung und der Inbetriebnahme des Windpark alpha ventus wurden umfangreiche Messungen an den Tragstrukturen und den Umgebungsparametern durchgeführt. Im Projekt Gigawind life wurde im TP1 ein Datenmanagementsystem zur kontinuierlichen und periodisch fortgeführten Datenauswertung für große Datenbestände (Big Data) entworfen und realisiert. Anhand von Performanceuntersuchungen konnte eine Verkürzung der Rechenzeit um den Faktor 10 in einem Rechencluster erreicht werden. Unter Anwendung einer Datenpipeline nach dem Publish/Subscribe Prinzip wird eine skalierbare Datenschnittstelle für Monitoringdaten vorgeschlagen.
Grouting is a universal repair and strengthening technique, which is constantly used for structural remediation of concrete components, trenches, mine subsidence, dam joints, restoration of masonry structures, and geological stabilizations. Having an extremely small particle size of only few microns, ultrafine cements are ideal for grouting applications due to their superior permeability and compressive strength properties of the hardened cement paste compared to that of the less-expensive, but coarser ordinary Portland cements. Supplementary cementitious materials (SCMs) are often used to replace ultrafine cement in order to modify certain properties and to reduce costs. The aim of this experimental study is to investigate the effect of three supplementary materials: microsilica (MS), fly ash (FA), and metakaolin (MK) on the workability, and mechanical properties of an ultrafine cement based grout with a constant water-binder ratio and constant superplasticizer content. Maximum percentages of replacement with ultrafine cement were 6% by volume of cement for MS and 16% for FA, and MK. In general, results suggest that the workability is improved by addition of FA, whereas is reduced, when modified with MS and MK. The compressive strength of grout after cement replacement remains comparable to that of pure cement grout. However, there is a tendency of the MS to positively affect the compressive strength opposite to FA, whereas flexural strength is positively affected by FA. Based on the results, it is evident that grouts with Hägerman cone flow more than 500 mm and compressive strength of more than 90 MPa after 28 days can be produced.
Surface erosion of a cohesive granular soil by a fluid flow is investigated numerically by coupling the Lattice Boltzmann Method (LBM) for the fluid phase and the Discrete Element Method (DEM) for describing the motion of the solid particles. In addition, inter-particles cohesion is insured by a contact model featuring a paraboloidal yield surface. The use of a fully resolved LBM-DEM coupling technique is currently limited due to the computational cost when simulating a large number of particles. This issue can be overcome using the graphics processing unit (GPU) thanks to ist massively parallel hardware architecture. Here, we first present a 2D GPU implementation of LBM-DEM coupling for a granular assembly. The GPU implementations are approximatively 30 times faster than a single core CPU version. Then, we apply the parallelization technique to practical erosional cases, namely the jet erosion test (JET) and the shear-driven erosion by a Couette flow. These numerical tests aim to relate micro parameters of a cohesive material (eg. cohesion) to macro parameters (eg. soil erodibility, mechanical strengths). Preliminary results show that micromechanical features indeed provide a novel insight of soil erosion phenomena.
The local asymptotic approach is promising for vibration-based fault diagnosis when associated to a subspace-based residual function and efficient hypothesis testing tools. It has the ability of detecting small changes in some chosen system parameters. In the residual function, the left null space of the observability matrix associated to a reference model is confronted to the Hankel matrix of output covariances estimated from test data. When this left null space is not perfectly known from a model, it should be replaced by an estimate from data to avoid model errors in the residual computation. In this paper, the asymptotic distribution of the resulting data-driven residual is analyzed and its covariance is estimated, which includes also the covariance related to the reference null space estimate. The importance of including the covariance of the reference null space estimate is shown in a numerical study.