A5087170731- Metal Alloys Wear and Properties
- Advanced machining processes and optimization
- Fatigue and fracture mechanics
- Welding Techniques and Residual Stresses
- Advanced Surface Polishing Techniques
- Civil and Structural Engineering Research
- Surface Treatment and Residual Stress
- Non-Destructive Testing Techniques
- Metal and Thin Film Mechanics
- Metal Forming Simulation Techniques
- Tunneling and Rock Mechanics
- Mechanical stress and fatigue analysis
- Erosion and Abrasive Machining
- Mechanical Behavior of Composites
- Additive Manufacturing Materials and Processes
- Metallurgy and Material Forming
- Microstructure and Mechanical Properties of Steels
Leibniz University Hannover
2020-2024
Abstract Background Commonly, polymer foil-based strain gauges are used for the incremental hole drilling method to obtain residual stress depth profiles. These prone errors due application by glue. For example zero setting is thus often erroneous necessary removal of foil and This resulting in wrong use calibration coefficients resolution leading calculations obtained Additionally common sensors limited their regarding e.g. exposure high temperatures. Objective paper aims at a first step...
Abstract During the joining of two metal sheets by welding, a process-specific geometry weld is created. The local created has decisive influence on its fatigue strength. This due to stress concentration at geometric notches. In this paper, process known from mechanical engineering called deep rolling applied butt welds. and after investigated. Additionally, novel automated measurement system using optical laser line scanning presented. qualified for evaluation regarding flank angles toe...
Abstract A more economical and resource‐saving construction of offshore wind energy converters is necessary in order to achieve climate policy objectives. Automated quality assurance welded joints offers a great potential enable less conservative manufacturing the support structures. The main objective this study find correlation between parameters that describe weld geometry fatigue life. Butt specimens were scanned with laser line sensor. seam including notch radius flank angle evaluated...
Welded joints show a comparably low fatigue strength compared to the base material. Thus, different post-weld treatment methods are used enhance of welded joints. A promising method metallic components is deep rolling process, but this has rarely been applied welds. For qualification process as an effective method, knowledge about its influence on surface and subsurface properties at critical weld toe necessary. Here, geometrical metallurgical inhomogeneities lead complex contact states...
Abstract Deep rolling is a machining process which used to decrease roughness and induce compressive residual stresses into component surfaces. A recent publication of this research group showed possibilities predict the topography during deep bars in lathe. Although can be milling machine flat specimens, it still unclear, whether predicted similar extend using application. To investigate influence parameters on topography, three experimental stages are performed paper cast AlSi10Mg. First,...
Hard turn rolling is a hybrid manufacturing process that affects the surface integrity of hardened components, aiming to enhance lifespan components such as bearings. combines thermal influence hard turning with subsequent deep modify properties and near layer. To better understand effects on AISI 52100 at elevated temperature are generated by process, finite element simulations were conducted analyze formation temperatures. These enable estimation workpiece surface, guiding optimal...
Abstract Für die Umsetzung der klimapolitischen Ziele ist eine wirtschaftliche und ressourcenschonende Bauweise von Offshore‐Windenergieanlagen (OWEA) dringend erforderlich. Die Erhöhung anzusetzenden Ermüdungsfestigkeit durch den Einsatz hochfester Stähle Anwendung Schweißnahtnachbehandlungsmethoden bietet großes Potenzial zur Senkung des Materialeinsatzes Kosten bei Monopiles. Speziell in automatisierten Fertigungskette OWEA bieten sich automatisierte Prozesse wie das Festwalzen an. ein im...
Abstract In this study, the influence of different measurement parameters energy dispersive residual stress measurements on obtained depth profiles deep rolled construction steel S355 G10+M was investigated. Especially diffraction angle θ and afterwards measuring time t per inclination ψ were varied. A = 20° shows an acceptable compromise between achievable information detected total intensity diffracted X-ray quanta. Furthermore, a 2,400 s leads to standard deviation regarding determined...
During butt welding of structural steels, an inhomogeneous material state across the weld occurs that has a detrimental influence on fatigue strength. In presented study, identification Lemaitre Chaboche elastoviscoplastic model parameters is shown. The was conducted for base material, heat affected zone and filler submerged arc welded 1.8813 (S355MLO) steel. derived constitutive integrated into finite element simulation deep rolling process, which not been investigated before post treatment...
Eigenspannungen sind maßgeblich für das Einsatzverhalten eines Bauteils und können auf vielfältige Weise bestimmt werden. Ein Verfahren, flexibel schnell tiefenaufgelöst den Eigenspannungszustand bestimmen kann, ist die Bohrlochmethode.
In April 2020, the world's first submerged full size slip joint was installed in Borssele V offshore wind farm.An extensive qualification programme terms of numerical modelling and testing (see photo) set up prior to installing joint.The farm offered a unique opportunity demonstrate industry that connection is fully feasible, certified ready for practical implementation (paper: Suur, S.; Hengeveld, F.).