7.2 Ingenieurbau
Filtern
Dokumenttyp
- Zeitschriftenartikel (48)
- Beitrag zu einem Tagungsband (15)
- Buchkapitel (2)
Referierte Publikation
- ja (65) (entfernen)
Schlagworte
- Compressive strength (4)
- Structural Health Monitoring (4)
- Structural health monitoring (4)
- Train passage (4)
- Damage detection (3)
- Fatigue (3)
- Hammer impact (3)
- Reliability (3)
- Slab track (3)
- Statistical tests (3)
- Axle impulses (2)
- Axle sequence (2)
- Bauwerksüberwachung (2)
- Bridge (2)
- Brücken (2)
- Earth block masonry (2)
- Ground vibration (2)
- Irregular soil (2)
- Model interpolation (2)
- Moisture content (2)
- Offshore (2)
- Relative humidity (2)
- Resonance (2)
- SHM (2)
- Soil erosion (2)
- Static axle loads (2)
- Structural systems (2)
- Subspace-based method (2)
- Train-induced ground vibration (2)
- Vehicle–track interaction (2)
- Wind turbine tower (2)
- Achsfolgespektren (1)
- Acoustic emission (1)
- Acoustic emission analysis (1)
- Ambient excitation (1)
- Ansys Autodyn (1)
- Artificial Intelligence (1)
- Attenuation (1)
- Automated Modal Analysis for Tracking Structural Change during Construction and Operation Phases (1)
- Automated operational modal analysis (1)
- Autonomous underwater vehicles (1)
- Ballast track (1)
- Bauteile (1)
- Bauwerke (1)
- Bauwerksdiagnostik (1)
- Bauwerksmonitoring (1)
- Bayesian analysis (1)
- Bayesian system identification (1)
- Belastungstest (1)
- Benchmark (1)
- Beschleunigungssensoren (1)
- Boundary element (1)
- Box-Behnken (1)
- Bridge resonance (1)
- Bridge vibration (1)
- Buckling soil-structure-interaction offshore piles track (1)
- Building and Construction (1)
- Cancellation (1)
- Cement-based composites (1)
- Cemented soil (1)
- Civil and Structural Engineering (1)
- Coating (1)
- Cohesive granular materials (1)
- Compaction grouting (1)
- Compliance function (1)
- Compression tests (1)
- Computational (1)
- Computer Vision (1)
- Concrete (1)
- Condensed Matter Physics (1)
- Continuous soil (1)
- Continuously inhomogeneous geological media (1)
- Continuously inhomogeneous soils (1)
- Crack Luminescence (1)
- Crack damage detection (1)
- Cracks (1)
- Cyber security (1)
- DUCON® (1)
- Damage Identification (1)
- Damage characterization (1)
- Damage evolution (1)
- Damage identification (1)
- Damage localization (1)
- Decision matrix analysis (1)
- Deterioration (1)
- Digital Image Correlation (DIC) (1)
- Digitalisierung (1)
- Discrete Element Method (1)
- Discrete element method (1)
- Drucker-Prager (1)
- Ductility (1)
- Dynamic axle loads (1)
- E-modulus (1)
- Earth blocks (1)
- Earth masonry (1)
- Elastische Gebäudelagerung (1)
- Environmental and Operational Variability (1)
- Environmental changes (1)
- Environmental effects (1)
- Ermüdung (1)
- Erosion (1)
- Estimation (1)
- Fatigue strength (1)
- Fault detection (1)
- Fault detectionchanging (1)
- Features (1)
- Fequency domain (1)
- Fibre optic sensors (1)
- Filter effects (1)
- Finite element (1)
- Finite element analysis (1)
- Finite elements (1)
- Finite-element boundary-element method (1)
- Fluid Dynamics (1)
- Fluidized beds (1)
- Fly ash (1)
- GPA (1)
- GPU Parallel computing (1)
- General Materials Science (1)
- Geology (1)
- Geometric vehicle and track irregularities (1)
- Granular cohesion (1)
- Granular materials (1)
- Grout (1)
- Grouted connection (1)
- Grouting (1)
- HAZID (1)
- High-rise building (1)
- Horizontal wind turbine (1)
- Hydraulic jet erosion (1)
- Impact (1)
- Impact loading (1)
- Imperfektion (1)
- Impinging jet (1)
- Inclination angle (1)
- Inspection (1)
- Inspection planning (1)
- Interface (1)
- Irregular ballast (1)
- Jacket support structure (1)
- Jet erosion test (1)
- Jet impingement (1)
- Kalibrierung (1)
- LBM-DEM (1)
- Laminar flow (1)
- Large components (1)
- Lateral dynamic displacement (1)
- Lattice Boltzmann Method (1)
- Lattice Boltzmann method (1)
- Layered soil (1)
- Layered soils (1)
- Linear parameter varying systems (1)
- Load identification (1)
- Load tests (1)
- Load vector (1)
- Load-bearing behaviour (1)
- Local approaches (1)
- Luminescence (1)
- Material Point Method (MPM) (1)
- Merkblatt (1)
- Metakaolin (1)
- Micro-reinforcement (1)
- Microfine Cement (1)
- Micromechanical modelling (1)
- Microsilica (1)
- Mitigation (1)
- Mix design (1)
- Mixed formulation (1)
- Mobile elements (1)
- Modal analysis (1)
- Modalanalyse (1)
- Model Building (1)
- Model Updating (1)
- Model update (1)
- Model updating (1)
- Modell-Update (1)
- Modulus of elasticity (1)
- Moisture (1)
- Monitoring (1)
- Monitoring-informed inspection and maintenance planning (1)
- Multi-beam track model (1)
- Non-Destructive Evaluation (1)
- Numerical modeling (1)
- Obstacles (1)
- Offshore geomechanics (1)
- Offshore pile foundation (1)
- Offshore steel structures (1)
- Offshore wind turbine (1)
- Optimal sensor placement (1)
- Perfectly Matched Layer (PML) (1)
- Piaui state (1)
- Pile bending stiffness (1)
- Pile foundation (1)
- Planar tomography (1)
- Post-impact evaluation (1)
- Pressure (1)
- Probability of Detection (1)
- Process noise (1)
- Quasi-static and dynamic tests (1)
- Quasi-static response; (1)
- Rail roughness (1)
- Railway (1)
- Railway bridge (1)
- Random dynamics and vibrations (1)
- Random stiffness variation (1)
- Randomly heterogeneous soil (1)
- Rechenmodelle (1)
- Recovery experiments (1)
- Rehabilitation (1)
- Reinforced concrete structure (1)
- Remote sensing vibrometer (1)
- Repair (1)
- Residual evaluation (1)
- Richtlinie (1)
- Risk (1)
- Risk-based design (1)
- SHCC (1)
- SHM environmental bridges (1)
- Safety (1)
- Sandstone (1)
- Santa-marta (1)
- Scattered axle impulses (1)
- Scattering (1)
- Schrauben (1)
- Serra da cangalha (1)
- Shell buckling (1)
- Shrinkage Reducing Admixture (1)
- Soil forces (1)
- Soil stiffness (1)
- Soil-structure interaction (1)
- Sorption isotherm (1)
- Static loading (1)
- Statistical evaluation (1)
- Statistical method (1)
- Statistical pattern recognition (1)
- Stereo photogrammetry (1)
- Stiffness variation (1)
- Strain (1)
- Strength (1)
- Stress-strain relation (1)
- Stress–strain-relation (1)
- Structural system identification (1)
- Strukturmonitoring (1)
- Subspace methods (1)
- Subspace-based residual (1)
- Superplasticizer (1)
- Supplementary Cementitious Materials (1)
- Sustainable binders (1)
- System identification (1)
- TRC (1)
- Temperature effect (1)
- Temperature effect rejection (1)
- Temperature modeling (1)
- Temperature rejection (1)
- Track deflection (1)
- Track displacements (1)
- Track filter (1)
- Track filtering (1)
- Track-soil interaction (1)
- Train-induced vibration (1)
- Transverse butt weld (1)
- Trench (1)
- Tunnel (1)
- Tunnel-to-surface reduction (1)
- UAS (1)
- UHPC (1)
- Ultrasonic testing (1)
- Umwelteinflüsse (1)
- Unbounded domain (1)
- Uncertainty (1)
- Uncertainty in reference (1)
- Uncertainty quantification (1)
- Value of information (1)
- Variational Bayesian statistics (1)
- Vehicle-track interaction (1)
- Verkehrsinfrastukturen (1)
- Vibration measurement (1)
- Vibration measurements (1)
- Vibrations (1)
- Viscosity (1)
- Vorspannung (1)
- Water Science and Technology (1)
- Wavenumber domain (1)
- Weld imperfections (1)
- Wheelset (1)
- Wind (1)
- Wind energy (1)
- Wind energy tower (1)
- Windenergieanlage (1)
- Windenergieanlagen (1)
- Workability (1)
- acceleration sensors (1)
- calibration (1)
- environmental influences (1)
- layered soil (1)
- temperature (1)
- transmission behavior (1)
- Übertragungsverhalten (1)
Organisationseinheit der BAM
- 7 Bauwerkssicherheit (65)
- 7.2 Ingenieurbau (65)
- 7.4 Baustofftechnologie (5)
- 8 Zerstörungsfreie Prüfung (4)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (2)
- 7.0 Abteilungsleitung und andere (1)
- 7.1 Baustoffe (1)
- 7.7 Modellierung und Simulation (1)
- 8.5 Röntgenbildgebung (1)
- 8.6 Faseroptische Sensorik (1)
Paper des Monats
- ja (5)
This paper presents an experimental study on the hydraulic failure of a submerged layer of cemented soil stressed by a localized upward water flow. Different mixtures of glass beads bonded with solid paraffin bridges were used as artificial material for the cemented granular soil. Variations in the cementation strength of the material were carefully introduced with different particle sizes and binder contents. The hydraulic fracture tests were then carried out with an upward flow injected at a controlled rate through a small section at the bottom of the samples. From a phenomenological perspective, the results reveal the existence of at least three modes of failure for a cemented soil layer: (1) overall block uplift, (2) block rupture by median crack at the inflow zone, and (3) progressive excavation of a fluidized path along the walls. The critical flow rate and pressure drop conditions at failure have been carefully quantified for the different mixtures and layer thicknesses, leading to a fair estimation of the hydraulic resistance of the samples, which here is found to be virtually independent of the grain size. However, the test results also showed inconsistent failure modes precluding so far the derivation of a simple phase diagram. Nevertheless, it was possible to rationalize all the measured data by employing appropriate modifications of the classical dimensionless numbers that describe the fluidization of purely frictional materials, whereby the cementation strength of the soil is quantified at the microscale through the yield tensile force of the intergranular bonds. Irrespective of its subsequent development, during which boundary conditions obviously play a major role, the initiation of the instability appears to take place very locally at the inlet when the drag force induced by the flow overcomes the cementation strength of the paraffin bonds. The results of this study thus appear to endorse the extension of the dimensional relationships of particulate systems in interaction with fluid flows to the case of cemented granular materials, in a similar vein as in recent previous studies.
Structural Health Monitoring (SHM) wird zunehmend zur kontinuierlichen Zustandsbewertung von Ingenieurbauwerken eingesetzt. Wichtige Bewertungsparameter sind globale Systemeigenschaften, wie z. B. Eigenfrequenzen, zu deren Bestimmung Beschleunigungssensoren eingesetzt werden. Häufig werden sog. MEMS-Sensoren (Micro Electro Mechanical Systems) verwendet, die jedoch ein hohes Rauschniveau aufweisen. Alternativ können rauschärmere IEPE-Sensoren (Integrated Electronics Piezo Electric) eingesetzt werden, die auch bei geringster Strukturanregung Schwingungen zuverlässig erfassen. Ferner besteht das Problem, dass Änderungen der Eigenfrequenzen infolge Bauwerksschädigung schwer von Änderungen der Eigenfrequenzen infolge Umwelteinflüssen zu unterscheiden sind. Letztere verändern die Eigenschaften der Struktur und die des Messsystems. Um Umwelteinflüsse auf das Messsystem im Anwendungsgebiet Ingenieurbau zu untersuchen, wurden IEPE-Beschleunigungsaufnehmer hinsichtlich ihres Übertragungsverhaltens im niederfrequenten Beschleunigungsbereich analysiert. Es zeigt sich, dass das Verhalten nicht nur frequenz-, sondern auch temperaturabhängig ist, während die Luftfeuchte keinen Einfluss hat. Diese für das Bauwerk unbedenklichen Einflüsse müssen für eine robuste Zustandsüberwachung kompensiert werden. Für die Anwendung im Ingenieurbau werden IEPE-Sensoren empfohlen, da sie ein hohes Signal-zu-Rausch-Verhältnis aufweisen und niederfrequente Bauwerksschwingungen zuverlässig erfassen.
Managing aging engineering structures requires damage identification, capacity reassessment, and prediction of remaining service life. Data from structural health monitoring (SHM) systems can be utilized to detect and characterize potential damage. However, environmental and operational variations impair the identification of damages from SHM data. Motivated by this, we introduce a Bayesian probabilistic framework for building models and identifying damage in monitored structures subject to environmental variability. The novelty of our work lies (a) in explicitly considering the effect of environmental influences and potential structural damages in the modeling to enable more accurate damage identification and (b) in proposing a methodological workflow for model‐based structural health monitoring that leverages model class selection for model building and damage identification. The framework is applied to a progressively damaged reinforced concrete beam subject to temperature variations in a climate chamber. Based on deflections and inclinations measured during diagnostic load tests of the undamaged structure, the most appropriate modeling approach for describing the temperature‐dependent behavior of the undamaged beam is identified. In the damaged state, damage is characterized based on the identified model parameters. The location and extent of the identified damage are consistent with the cracks observed in the laboratory. A numerical study with synthetic data is used to validate the parameter identification. The known true parameters lie within the 90% highest density intervals of the posterior distributions of the model parameters, suggesting that this approach is reliable for parameter identification. Our results indicate that the proposed framework can answer the question of damage identification under environmental variations. These findings show a way forward in integrating SHM data into the management of infrastructures.
Wind turbines are exposed to a high number of load cycles during their service lifetime. Therefore, the fatigue strength verification plays an important role in their design. In general, the nominal stress method is used for the fatigue verification of the most common used butt-welded joints. The Eurocode 3 part 1–9 is the current design standard for this field of application. This paper presents recent results of fatigue tests on small-scaled specimens and large components with transverse butt welds to discuss the validity of the FAT-class. Furthermore, results from numerical simulations for the verification with the effective notch stress and the crack propagation approach are used for comparison. Based on the consistency between the numerical results and the fatigue tests, the influence of the seam geometry on the fatigue resistance was investigated. Finally, a prediction of the fatigue strength of butt-welded joints with plate thicknesses up to 80 mm was carried out.
This paper scopes the specialties of a hazard identification study for large and extra-large unmanned undersea vehicles (UUVs). A generic node/function structure is derived from different large and extra-large UUV designs, partially own vehicle designs from research projects, and partially from commercial vehicles. For each node, a short overview of its components and the proper function or operations is defined. A set of guide words is used to prompt a hazard discussion for each node, which identifies unwanted functions, resulting in potential hazards and unmitigated consequences. Related to the SafeMASS-Report from DNV, this work concentrates on selected topics of the bridge-related function on voyage, control & monitoring, and abnormal situations. For unmanned vehicles without any person on board, these three topics become more important for underwater vehicles with very limited connectivity or temporary disruptions of communication whereby an operator in a remote-control center could only be provided with rough vehicle or mission states. Therefore, vehicle control, whether in hard- or software, must handle most tasks belonging to the considered functions automatically or autonomously. Hence, the most appropriate reactions of the system to unwanted system
behavior must be implemented. This HAZID study could, on the one hand, be used as background for such an implementation, and on the other hand, it is used to verify the implemented actions on the risks and hazards.
We evaluate masked block-structured grids for ocean domains which allow to represent small-scale geometric features without resorting to very small blocks or excessive mesh resolution. The considered approach aims to combine the geometric flexibility of unstructured meshes with the computational efficiency of stencil-based discretizations and is implemented and tested in a quadrature-free discontinuous Galerkin shallow water solver. We investigate the accuracy and the computational performance of the scheme on a range of realistic ocean domains meshed with blocks of different size and provide some comparisons to results obtained on unmasked block-structured grids and unstructured meshes.
Impact resistance of reinforced concrete (RC) structures can be significantly improved by strengthening RC members with thin composite layers featuring high damage tolerance. Indeed, to limit the well-known vulnerability of cement-based materials against impact loading, the synergistic effects of short fibres and continuous textile meshes as hybrid reinforcement has been proved to be highly beneficial. This paper addresses the characterisation of novel cement-based hybrid composites through accelerated drop-weight impact tests conducted on rectangular plates at different impact energies. Two distinct matrices are assessed, with particular interest in a newly developed limestone calcined clay cement (LC3)-based formulation. Important parameters quantifying energy dissipation capability, load bearing capacity and damage are cross-checked to compute the ballistic limit and estimate the safety-relevant characteristics of the different composites at hand. Although textiles alone can improve the damage tolerance of fine concrete to some extent, the crack-bridging attitude of short, well-dispersed fibres in hybrid composites imparts a certain ductility to the cement-based matrices, allowing a greater portion of the textile to be activated and significantly reducing the amount of matrix spalling under impact.
Information on the condition and reliability of an offshore jacket structure provided by a vibration-based structural health monitoring system can guide decisions on inspection and maintenance. When selecting the sensor setup, the designer of the monitoring system must assess its overall benefit compared to its costs before installation. The potential benefit of continuously monitoring the dynamic response of a jacket structure can be formally quantified through a value of information analysis from Bayesian decision theory. In this contribution, we present a framework for optimizing the placement of vibration sensors on offshore jacket structures by maximizing the value of information of the monitoring system. To solve the resulting discrete optimization problem, we adapt a genetic algorithm. The framework is demonstrated in a numerical example considering a redundant jacket-type steel frame. The numerical study shows that monitoring the vibration response of the frame is beneficial. Good sensor setups consist of relatively few sensors located towards the upper part of the
frame. The adapted genetic algorithm performs similarly well as established sequential sensor placement algorithms and holds substantial promise for application to real jacket structures.
In this article, a partial selection of experiments on enhancing the impact resistance of structural components with non-metallic, textile-reinforced concrete is discussed. The focus is on the experimental investigations in which the impact resistance of thin, textile-reinforced concrete plates is characterized. The article discusses the materials, fabrics and test setup used. For the experimental work, a drop tower from the Otto Mohr Laboratory, which belongs to the Technische Universtät Dresden, was used. Furthermore, the experimental results are presented and evaluated using different methods. Based on the collected data, a suitable approach to determining the perforation velocity of an impactor through the investigated thin, textile-reinforced concrete plates is shown.
The vehicle–track interaction generates forces and consequently vibrations in the environment. The interaction has been analysed by the simultaneous measurements of vehicle, track and ground vibrations during test runs with varied train speeds. The special effects of the passage over a bridge and through a tunnel are studied and compared with the measurements on a conventional ballasted surface line. The maximum amplitudes, narrow band and one-third octave band spectra are presented for the axle-box accelerations and for the track, bridge and ground vibrations. The different frequencies and frequency bands are related to wheel out-of-roundness, track alignment errors, the sleeper passage and the wheelset–track resonance. An axle impulse component has been observed at the track, at the near-field soil and as a scattered version in the far field. Specific results can be found for the bridge track, where clearly speed-dependent bridge resonances occur due to the axle sequence of the train, and for the tunnel track where soft rail pads are responsible for a strong amplification around the wheelset–track resonance. On the other hand, the axle impulses are strongly reduced by the tunnel track, and the scattered axle impulse component is not as relevant as for the surface track. As a consequence, a strong mid-frequency amplitude reduction of the tunnel compared to the surface line has been measured for low and high train speeds by the Federal Institute of Material Research and Testing (BAM) and by other institutes.