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De Boer, A. (author), Hendriks, M.A.N. (author), Van der Veen, C. (author), Belletti, B. (author)
conference paper 2015
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In Taylor-Couette flow, the radius ratio ($\eta = r_i/r_o$) is one of the key parameters of the system. For small $\eta$, the asymmetry of the inner and outer boundary layer becomes more important, affecting the general flow structure and boundary layer characteristics. Using high-resolution particle image velocimetry we measure flow profiles...
conference paper 2015
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In this talk we focus on the velocity fluctuations in highly turbulent Taylor-Couette flow for the case of stable flow (constant rotation) and for decaying flow. Turbulent flows are generally characterized by the range of scales of their fluctuations, and a statistical description of the flow is often done by calculating the correlations of...
conference paper 2015
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Van der Veen, A.C. (author), Coenders, J.L. (author), Veer, F.A. (author), Nijsse, R. (author), Houtman, R. (author), Schonwalder, J. (author)
At this point in time, 3D-printing techniques in general, but especially applied for the building industry, still are in a phase of early experiments. One of the experimental attempts is to print a full-scale, three-story high, house in Amsterdam, using an up scaled version of a FDM-printer that is able to print blocks of 1.8 x 1.8 x 3.0 meters...
conference paper 2015
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Ensink, S.W.H. (author), Van der Veen, C. (author), De Boer, A. (author)
Experimental results of four shear tests on two large prestressed concrete beams are compared to nonlinear analysis and design code calculations. The beams have a length of 12 m and a depth of 1.3 m and are reinforced with stirrups and pre-tensioning. The four tests consist of a single point load at a distance of 2.7d from the support. A priori...
conference paper 2015
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), De Boer, A. (author)
Slabs subjected to concentrated loads close to supports, as occurring for truck loads on slab bridges, are less studied than beams in shear or slab-column connections in punching. To predict the shear capacity for this case, the Bond Model for concentric punching shear was studied initially. Modifications to this model resulted in the Modified...
conference paper 2015
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Van Ormondt, D. (author), De Beer, R. (author), Van der Veen, J.W.C. (author), Sima, D.M. (author), Graveron-Demilly, D. (author)
MRI-scanners enable non-invasive, in vivo quantitation of metabolites in, e.g., the brain of a patient. Among other things, this requires adequate estimation of the unknown temporal decay function of the complex-valued signal emanating from the metabolites. We propose a method to render a current decay estimator more simple, accurate, and robust...
conference paper 2015
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), De Boer, A. (author)
The shear problem is typically studied by testing small, heavily reinforced, slender beams subjected to concentrated loads, resulting in a beam shear failure, or by testing slab-column connections, resulting in a punching shear failure. Slabs subjected to concentrated loads close to supports, as occurring when truck loads are placed on slab...
conference paper 2014
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), De Boer, A. (author)
For an initial design or assessment of a reinforced concrete solid slab bridge, spreadsheet-based or hand calculations are typically used. The shear stress is compared to the shear capacity as prescribed by the code. The distributed loads result in a uniform shear stress at the support. Concentrated loads are less straightforward to take into...
conference paper 2014
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Amir, S. (author), Van der Veen, C. (author), Walraven, J.C. (author), De Boer, A. (author)
The research subject of this paper is the bearing capacity of transversely prestressed concrete bridge decks between concrete girders under concentrated loads. Experiments on a 1:2 scale model of this bridge were carried out in the laboratory and a 3D nonlinear finite element model was developed in the FEA software package DIANA to study the...
conference paper 2014
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Amir, S. (author), Van der Veen, C. (author), Walraven, J.C. (author), De Boer, A. (author)
In the Netherlands, most of the bridges were built more than 50 years ago and it is essential for designers to find out if these bridges are safe for modern traffic especially in shear since that was not considered in design recommendations before 1976. Detailed experiments have been carried out in the laboratory to investigate punching shear...
conference paper 2014
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Lantsoght, E.O.L. (author), De Boer, A. (author), Van der Veen, C. (author), Walraven, J.C. (author)
conference paper 2014
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), Walraven, J.C. (author), De Boer, A. (author)
The combination of increased live loads and a more conservative shear capacity in the recently implemented Eurocodes, resulted in a large number of existing solid slab bridges in the Netherlands being shear-critical upon assessment. However, an enhancement of the shear capacity can occur in slabs under concentrated wheel loads due to transverse...
conference paper 2013
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Rajan, R.T. (author), Van der Veen, A.J. (author)
Synchronization and localization are critical challenges for the coherent functioning of a wireless network of mobile nodes. In this paper, a novel joint non-linear range and affine time model is presented based on two way time stamp exchanges, extending an existing affine time-range model. For a pair of nodes, a closed form pairwise least...
conference paper 2013
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), Walraven, J.C. (author)
A large number of existing reinforced concrete slab bridges are found to be insufficient for shear when calculated according to the governing codes. Seeking improved methods, for example, based on new experimental evidence, to assess the residual shear capacity and prolonging their service life can avoid large economic, environmental and social...
conference paper 2013
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), Walraven, J.C. (author)
Previous experimental research at Delft University of Technology indicated an increased shear capacity of slabs under concentrated loads as a function of decreasing distance to the adjacent line support. Expressions have been derived for this increase, including the definition of an appropriate effective width. However, it is unknown if the...
conference paper 2013
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), Walraven, J.C. (author), De Boer, A. (author)
The capacity of reinforced concrete solid slab bridges in shear is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the permanent actions and live loads. Results from experiments on half-scale continuous slab bridges are used to develop a set of recommendations for the assessment of...
conference paper 2013
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Lantsoght, E.O.L. (author), Van der Veen, C. (author), Walraven, J.C. (author)
Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punching and shear. This behaviour is studied in a...
conference paper 2013
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Van der Veen, J.W. (author), Van Ormondt, D. (author), De Beer, R. (author)
In this work we report on generating/using simulated metabolite basis sets for the quantification of in vivo MRS signals, assuming that they have been acquired by using the PRESS pulse sequence. To that end we have employed the classes and functions of the GAMMA C++ library. By using several versions of our PRESS-simulation program, we were able...
conference paper 2012
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Amir, S. (author), Van der Veen, C. (author), Walraven, J.C. (author)
In the Netherlands, there is a need to determine the capacity of bridge decks as a large number of them were built back in the 60’s and 70’s. Since then, not only a lot of additional safety requirements have been incorporated into the modern codes but the traffic flow has also increased drastically. The current research deals with this question...
conference paper 2012
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