Searched for: subject%3A%22stiffness%22
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Kumar, P. (author), Frouws, Jan (author), Langelaar, Matthijs (author)
In various applications, design problems involving structures and compliant mechanisms experience fluidic pressure loads. During topology optimization of such design problems, these loads adapt their direction and location with the evolution of the design, which poses various challenges. A new density-based topology optimization approach...
journal article 2020
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Mirra, M. (author), Ravenshorst, G.J.P. (author), van de Kuilen, J.W.G. (author)
Traditional timber floors cannot normally withstand horizontal seismic loads without large deformations. This may lead to a corresponding out-of-plane collapse of masonry walls in existing buildings. This situation is even more critical in the Netherlands, around the city of Groningen, where human-induced earthquakes started to take place....
journal article 2020
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Fleischer, J.C. (author), Diehl, J.C. (author), Wauben, L.S.G.L. (author), Dankelman, J. (author)
Three-dimensional (3D) printing may be a solution to shortages of equipment and spare parts in the healthcare sector of low- and middle-income countries (LMICs). Polylactic acid (PLA) for 3D printing is widely available and biocompatible, but there is a gap in knowledge concerning its compatibility with chemical disinfectants. In this study, 3D...
journal article 2020
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Schut, I.M. (author), Pasma, J.H. (author), Roelofs, J. M.B. (author), Weerdesteyn, V. (author), van der Kooij, H. (author), Schouten, A.C. (author)
Changes in human balance control can objectively be assessed using system identification techniques in combination with support surface translations. However, large, expensive and complex motion platforms are required, which are not suitable for the clinic. A treadmill could be a simple alternative to apply support surface translations. In...
journal article 2020
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Griffioen, M. (author), van Drunen, P. (author), Maaswinkel, E. (author), Perez, R. S.G.M. (author), Happee, R. (author), van Dieën, J. H. (author)
Purpose: The goal of this study was to assess differences in low back stabilization and underlying mechanisms between patients with low back pain (LBP) and healthy controls. It has been hypothesized that inadequate trunk stabilization could contribute to LBP through high tissue strains and/or impingement. Evidence to support this is...
journal article 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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Cao, Xiaoluo (author), Wu, Linmei (author), Li, Z. (author)
A computational model for studying the mechanical performance of steel-concrete columns under combined torsion is established via ABAQUS. The model is validated by experimental results. Through numerical simulations, the influence of the axial load ratio, torsion-bending ratio, concrete strength, steel ratio, longitudinal reinforcement ratio,...
journal article 2020
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Kongshaug, Simen Sørgaard (author), Oseland, Oddbjørn (author), Kanstad, Terje (author), Hendriks, M.A.N. (author), Rodum, Eva (author), Markeset, Gro (author)
The alkali silica reaction (ASR) in concrete causes internal localized swelling and micro cracking, which result in expansion and correlated deterioration of the concrete material. The stress state of the concrete is known to affect expansion due to ASR, with an anisotropic stress state giving rise to anisotropic expansion. Similarly, the...
journal article 2020
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Konstadinou, M. (author), Bezuijen, A. (author), Greeuw, G. (author), Zwanenburg, C. (author), van Essen, H. M. (author), Voogt, L. (author)
A series of undrained cyclic direct simple shear (CDSS) tests on dense Toyoura sand has been performed with the aim to investigate the influence of the stiffness of the DSS device on test results. To this end, springs were installed to reduce deliberately the stiffness of the apparatus. It is shown that the cyclic resistance of the sand...
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 introduces a new semi-active strategy for vibration control of truss and frame structures equipped with variable stiffness and damping joints which consist of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin. When the joints are actuated to the transition temperature through thermal actuation, the SMP...
journal article 2020
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Lu, T. (author), Metrikine, A. (author), Steenbergen, M.J.M.M. (author)
A periodically supported beam on a visco-elastic half-space is considered to model the vibration of railway tracks. The viscosity of the half-space is assumed to be of the Kelvin-Voigt type. Making use of the concept of equivalent dynamic stiffness, the reaction of the half-space to the sleepers is replaced by a system of identical spring...
journal article 2020
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Zhang, H. (author), Anupam, K. (author), Scarpas, Athanasios (author), Kasbergen, C. (author), Erkens, S. (author), Al Khateeb, Loay (author)
The mechanical properties of asphalt mixture are always required for the evaluation of the durability of pavements. In order to obtain these properties without conducting expensive laboratory tests and using calibrated empirical models, research studies have been carried out to develop micromechanics-based models. Continuum-based...
review 2020
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Dillinger, J.K.S. (author), Abdalla, M.M. (author), Meddaikar, M.Y. (author), Klimmek, Thomas (author)
This paper presents an aero load correction strategy applicable to the static aeroelastic optimization of composite wings. The optimization framework consists of a successive convex subproblem iteration procedure, in which a gradient-based optimizer consecutively solves a local approximation problem. Responses are approximated as a linear and...
journal article 2019
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Liu, Faqi (author), Yang, Hua (author), Yan, R. (author), Wang, Wei (author)
The behaviour of square steel tube confined reinforced concrete columns after fire exposure was studied experimentally and numerically in this paper. Eighteen stub columns were first heated following the ISO 834 standard fire including both heating and cooling phases, and were subsequently loaded to failure after cooling to ambient temperature....
journal article 2019
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Labans, E. (author), Bisagni, C. (author)
The ability to steer carbon fibre tapes, varying the tow angle, can widen the designs possibilities of cylindrical shells that are one of the main components of aerospace structures. This research presents experimental and numerical investigation of two carbon fibre reinforced plastic cylindrical shells – a cylinder with conventional layup made...
journal article 2019
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Peeters, D.M.J. (author), Irisarri, François Xavier (author), Groenendijk, Chris (author), Růžek, Roman (author)
Composite materials are finding increasing application, for example in commercial aircraft. Traditionally fiber angles are restricted to 0°,±45° and 90°. The current work exploits the possibility of using multiple ’non-conventional’ laminates where either fiber steering (‘variable stiffness’), ply drops (‘variable thickness’), or a...
journal article 2019
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Castro, Saullo G.P. (author), Donadon, Maurício V. (author), Guimarães, Thiago A.M. (author)
The increasing need for automatic mesh generation has led to the development of efficient triangulation algorithms that are able to discretize any 2D or 3D domain. Modern finite element formulations based on strain smoothing techniques (SFEM) provide enhanced convergence properties, preventing yet the stiffening behavior of triangular meshes....
journal article 2019
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Waterval, Niels F.J. (author), Nollet, Frans (author), Harlaar, J. (author), Brehm, Merel Anne (author)
BACKGROUND: To improve gait, persons with calf muscle weakness can be provided with a dorsal leaf spring ankle foot orthosis (DLS-AFO). These AFOs can store energy during stance and return this energy during push-off, which, in turn, reduces walking energy cost. Simulations indicate that the effect of the DLS-AFO on walking energy cost and...
journal article 2019
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Bier, H.H. (author), Wang, Qinyu (author), Teuffel, Patrick (author), Senatore, Gennaro (author)
The environment around buildings keeps changing, while the static design solutions of buildings cannot perform well during the whole service life. In order to improve structural performances including strength (i.e. avoid collapse) and serviceability, adaptive structures are likely to establish as one of future trends in both research and...
journal article 2019
Searched for: subject%3A%22stiffness%22
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