Searched for: subject%3A%22natural%255C%2Bfrequency%22
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Tempelman, Koen (author)
As the world's population keeps increasing and the rate of urbanizations increases, The rate at which high-rise structures are being built is skyrocketing. In the Netherlands, this is no different. It is expected that the amount of high-rise structures taller than 70 meters will more than double in the coming 20 years. As these structures become...
master thesis 2022
document
Liu, Ganzhong (author), Cong, Jianli (author), Wang, Ping (author), Du, Shuai (author), Wang, L. (author), Chen, Rong (author)
The vertical vibration and transmission characteristics of ballast are key factors that affect the dynamic stability of railway track structures and control the settlement of ballasted beds. Therefore, the following study was conducted to explore this topic. Firstly, through an impact hammer test on a ballast sensor with embedding chip, the...
journal article 2022
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Zomerdijk, M.J.J. (author), van der Wijk, V. (author)
Industrial robotic manipulators in pick-and-place applications require short settling times to achieve high productivity. The fluctuating reaction forces and moments on the base of a dynamically unbalanced manipulator, however, cause base vibrations, leading to increased settling times. These base vibrations can be eliminated with dynamic...
journal article 2022
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Zomerdijk, Matthijs (author)
High accelerations in unbalanced robotic manipulators can induce significant base vibrations, which reduces precision and increases settling time. These vibrations are caused by fluctuating reaction forces and reaction moments exerted on the base by the manipulator. Dynamic balancing eliminates these fluctuations and therefore improves...
master thesis 2020
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Hoevenaars, A.G.L. (author), Krut, S. (author), Herder, J.L. (author)
The dynamic performance of a parallel manipulator is often limited by its natural frequencies. These frequencies are a result of the controlled actuator stiffness and the mechanical design. Typically, only the lowest natural frequencies are of interest. However, existing methods to analyze natural frequencies of parallel manipulators with...
journal article 2020
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Wang, Qinyu (author), Senatore, Gennaro (author), Jansen, K.M.B. (author), Habraken, Arjan (author), Teuffel, Patrick (author)
This paper presents design and characterization of a new type of structural joint which can vary its stiffness through actuation. Stiffness variation is employed to control the dynamic response of frame structures equipped with such joints. The joint is made of a shape memory polymer (SMP) core which is reinforced by an SMP-aramid composite...
journal article 2020
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Mulders, S.P. (author), Hovgaard, Tobias Gybel (author), Grunnet, Jacob Deleuran (author), van Wingerden, J.W. (author)
With the ever increasing power rates of wind turbines, more advanced control techniques are needed to facilitate tall towers that are low in weight and cost-effective but in effect more flexible. Such soft-soft tower configurations generally have their fundamental side-side frequency in the below-rated operational domain. Because the turbine...
journal article 2020
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Skukis, Eduards (author), Jekabsons, Gints (author), Andersons, Jānis (author), Ozolins, Olgerts (author), Labans, E. (author), Kalnins, Kaspars (author)
Thin-walled carbon fiber reinforced plastic (CFRP) shells are increasingly used in aerospace industry. Such shells are prone to the loss of stability under compressive loads. Furthermore, the instability onset of monocoque shells exhibits a pronounced imperfection sensitivity. The vibration correlation technique (VCT) is being developed as a...
journal article 2020
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Kementzetzidis, E. (author), Corciulo, Simone (author), Versteijlen, Willem G. (author), Pisano, F. (author)
The development of the offshore wind industry is motivating substantial research efforts worldwide, where offshore wind turbines (OWTs) of increasing size are being installed in deeper water depths. Foundation design is a major factor affecting the structural performance of OWTs, with most installations founded to date on large-diameter...
journal article 2019
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Đilas, Luka David (author)
Offshore wind has achieved many milestones considering this relatively new and emerging industry. Its huge advancement is mostly driven by lowering the overall project cost and renewable energy targets which are set by the EU. One of the potential cost savers can be found in the foundation structure design in which the monopiles are the most...
master thesis 2018
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Descourtieux, Emeric (author)
One way to implement a wind turbine in the sea is to use lattice structures. Since these structures are placed offshore, they must be able to withstand all kinds of loads. It is essential that the eigenfrequencies of the support structure do not correspond to the passing frequencies of the blades and any other dynamic actions. To avoid this the...
master thesis 2018
document
Versteijlen, W.G. (author)
Offshore wind generated electricity is currently one of the most promising sources of energy to contribute in creating a sustainable global energy mix. The latter is essential for minimising the detrimental impact of human-induced accelerated climate change. The cost of offshore wind power has strongly decreased over the past years due to ...
doctoral thesis 2018
document
Middelweerd, luuk (author)
In the Dutch coastal waters more and more wind turbines on monopile foundations are built. An important design parameter is the first natural frequency of the wind turbine. The first natural frequency is dependent on environmental conditions and different soil conditions such as scour. This research gives a better insight into the sensitivities...
master thesis 2017
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Veerman, R.P. (author)
The Dutch road infrastructure contains a large number of concrete bridges and viaducts. Malfunction of these bridges and viaducts has large financial consequences. To avoid malfunctions of bridges, bridges need to be inspected frequently and actions should be taken when required. The reliability of the inspections of the health of a bridge could...
doctoral thesis 2017
document
Kementzetzidis, Evangelos (author)
In recent years, offshore wind is becoming an increasingly growing market in Europe. Many resources are allocated towards ensuring its sustainable progress while one of the biggest uncertainties encountered lays in the offshore wind turbine's (OWT) foundations. In Europe, monopiles are the most widely adopted solution to found such structures in...
master thesis 2017
document
Versteijlen, W.G. (author), Metrikine, A. (author), van Dalen, K.N. (author)
A procedure is presented for the derivation of an effective small-strain soil stiffness governing the soil– structure interaction of large-diameter monopiles. As a first step, geophysical measurements are used to estimate the depth-dependent shear modulus G of the soil stratum. The second step is to use this modulus and an estimated Poisson’s...
journal article 2016
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Versteijlen, W.G. (author), Van Dalen, K.N. (author), Metrikine, A. (author), Hamre, L. (author)
In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for two soil-structure interaction (SSI) models to assess the initial soil stiffness for offshore wind turbine foundations. This stiffness has a defining influence on the first natural frequency of offshore wind turbines (OWTs),...
conference paper 2014
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Veerman, R.P. (author), Koenders, E.A.B. (author)
Structural Health Monitoring (SHM) systems are frequently used in civil infrastructures. One important durability property in reinforced concrete (RC) structures is the level of steel bar corrosion. In a dynamic four-point-bending test, two beams are loaded simultaneously, in which corrosion is accelerated in one of them. Since geophones are...
conference paper 2014
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Kooreman, B.D. (author)
Satellite-based soil moisture measurements indicate a diurnal variation in backscatter in west Africa. This diurnal variation is assumed to be caused by variation of moisture content in vegetation (Friesen, 2008). The obtained satellite soil moisture data can be improved, if ground measurements support this hypothesis. Especially at locations...
master thesis 2013
document
Chiriboga Arroyo, P.G. (author)
Preventing vibration damage from occurring to valuable and sensitive canvas paintings is of main concern for museums and art conservation institutions. This concern has grown in recent years due to the increasing demand of paintings for exhibitions worldwide and the concomitant need for their handling and transport. The vibration of the canvas...
doctoral thesis 2013
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