Searched for: subject:"stiffness"
(1 - 20 of 121)

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Jia, W. (author), Markine, V.L. (author), Jing, Guoqing (author)
Under the high requirement of ballast materials and the frequent maintenance of high-speed and heavy-haul railway, the maintenance cost and material consumption become an important problem. Several methods are used to increase the stability and service life of railway structure, also using recycled materials in ballast bed construction can be a...
journal article 2021
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Sabbadini, S. (author)
Diastolic heart failure is one of the principal causes of death in Western countries, and there is currently no treatment available; prevention, on the other hand, may be possible, provided an early enough diagnosis. The worsening of diastolic functionality is associated with increased values of cardiac stiffness, which could therefore provide a...
doctoral thesis 2021
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Amoozandeh Nobaveh, A. (author), Radaelli, G. (author), Herder, J.L. (author)
A method to achieve symmetric kinetostatic behaviour in an extensive working range at the endpoint of an asymmetric spatial beam, using cross-section optimization, is presented. The objective function of the optimization is defined as expanding the beam working range to the desired region, simultaneously maximizing symmetric behaviour in it....
book chapter 2021
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de Oliveira Barbosa, J.M. (author), Faragau, A.B. (author), van Dalen, K.N. (author)
The procedure presented in this work aims at providing a framework for studying settlement of ballast in zones with stiffness variation of the railway track support. The proposed procedure results from expanding an existing infinite periodic model of a railway track to account for variations in the stiffness of the foundation. Ballast is...
journal article 2021
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Shen, C. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)
We propose to combine a physics-based finite element (FE) track model and a data-driven Gaussian process regression (GPR) model to directly infer railpad and ballast stiffness from measured frequency response functions (FRF) by field hammer tests. Conventionally, only the rail resonance and full track resonance are used as the FRF features to...
journal article 2021
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Kuppens, P.R. (author), Bessa, M.A. (author), Herder, J.L. (author), Hopkins, J. B. (author)
We introduce two essential building blocks with binary stiffness for mechanical digital machines. The large scale fully compliant mechanisms have rectilinear and rotational kinematics and use a new V-shaped negative stiffness structure to create two extreme states of stiffness by static balancing. The use of a mechanical bistable switch...
journal article 2021
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Vertonghen, L.E.M. (author), Castro, Saullo G.P. (author)
Previous research has hinted on further improvements of the buckling behaviour of variable-stiffness laminates by incorporating overlaps, resulting in a variable thickness profile that is non-linearly coupled to the steering angles. The present study compares two modelling strategies to consider the variable thickness distribution: 1) as...
journal article 2021
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Kuppens, P.R. (author), Bessa, M.A. (author), Herder, J.L. (author), Hopkins, J. B. (author)
Stiffness in compliant mechanisms can be dramatically altered and even eliminated entirely by using static balancing. This requires elastic energy to be inserted before operation, which is most often done with an additional device or preloading assembly. Adding such devices contrasts starkly with primary motivations for using compliant...
journal article 2021
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van Assenbergh, S.P. (author), Culmone, C. (author), Breedveld, P. (author), Dodou, D. (author)
Current surgical grippers rely on friction grip, where normal loads (i.e. pinch forces) are translated into friction forces. Operating errors with surgical grippers are often force-related, including tissue slipping out of the gripper because of too low pinch forces and tissue damaging due to too high pinch forces. Here, we prototyped a...
journal article 2021
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Shi, Can (author), Zhao, Chunfa (author), Yang, Yang (author), Guo, Y. (author), Zhang, Xu (author)
Railway ballasted track stiffness is an important indicator to identify supporting condition that ensures that the facility is well designed and functioned. Although many studies have been performed on track stiffness based on experimental tests and finite-element methods, the factors influencing the track stiffness have not been completely...
journal article 2021
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Natella, M. (author)
The process of designing an aircraft is generally divided in three phases, namely the conceptual, preliminary and detailed. The whole process is one that involves various disciplines and is subject to multiple constraints. Traditionally the different aspects of the design process are tackled separately by different departments within a company....
doctoral thesis 2020
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Socci, Carlo Alberto (author), Kassapoglou, C. (author)
A model is described which allows the exact calculation of stresses in a cracked ply under combined state of strain. Closed form expressions for the stresses in each ply are combined in an energy density-based criterion to predict crack spacing and the resulting transverse modulus and shear modulus. Inelastic effects due to non-linearities of...
journal article 2020
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Hong, Z. (author), Peeters, D.M.J. (author), Turteltaub, S.R. (author)
In this paper, design strategies are developed to explore better approaches of enforcing local layer-wise curvature constraints in the optimization of variable stiffness laminates in order to ensure the manufacturability of optimized designs based on the limitations of automated fiber placement. The methods developed here aim to improve an...
journal article 2020
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Lampaert, S.G.E. (author)
The bearing and the seal are two commonly used tribological components since nearly all moving machinery relies on them for proper operation. Even a small improvement in these components can have a big impact on both the market and the environment. The two main problems of these components are wear and friction. In addition, seals suffer from...
doctoral thesis 2020
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Anand, C. (author), Groves, R.M. (author), Benedictus, R. (author)
Ultrasonic testing using arrays is becoming widely used to test composite structures in the Aerospace industry. In recent years, the Full Matrix Capture (FMC) technique has been implemented to extract the signals for post-processing to form an image. The inherent anisotropy and the layering of the structure pose challenges for the...
journal article 2020
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Zucco, G. (author), Oliveri, V. (author), Rouhi, M. (author), Telford, R. (author), Clancy, G. (author), McHale, C. (author), O'Higgins, R. (author), Young, T. M. (author), Weaver, P. M. (author), Peeters, D.M.J. (author)
Automated manufacturing of thermoplastic composites has found increased interest in aerospace applications over the past three decades because of its great potential in low-cost, high rate, repeatable production of high performance composite structures. Experimental validation is a key element in the development of structures made using this...
journal article 2020
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Hong, Z. (author)
Reducing weight and improving strength of structures have always been major design goals in the aerospace industry since its inception. In particular, strength directly affects the safety and serviceability of an airplane and is therefore of great importance in structural design. Improving the strength of an airframe can effectively increase its...
doctoral thesis 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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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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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
Searched for: subject:"stiffness"
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