Dynamic Response of FRCM Reinforced Masonry Arches

2019 ◽  
Vol 817 ◽  
pp. 285-292 ◽  
Author(s):  
Anna Castellano ◽  
Aguinaldo Fraddosio ◽  
Jacopo Scacco ◽  
Gabriele Milani ◽  
Mario Daniele Piccioni

The problem of the dynamic behavior of masonry arches and vaults has gained increasing interest in recent years, since the key role of these structural elements in the masonry constructions, especially of historic interest. Despite this, the literature still lacks a sufficiently large number of contributions on this important subject, and this deficiency is even more marked for the case of reinforced masonry. In this context, the present paper shows and discusses some preliminary experimental results on full-scale dynamic tests on unreinforced and GFRCM-reinforced Apulian tuff masonry arches. The experiments have been performed by using a test bench appositely designed and built; the dynamic excitation consisted of a harmonic base motion with fixed amplitude and increasing frequency. The acceleration in suitable points of the arches, the base shear and the base motion have been continuously monitored during the tests.

2014 ◽  
Vol 624 ◽  
pp. 502-509 ◽  
Author(s):  
Ismael Basilio ◽  
Roberto Fedele ◽  
Paulo B. Lourenço ◽  
Gabriele Milani

In this contribution, original limit analysis numerical results are presented dealing with some reinforced masonry arches tested at the University of Minho-UMinho, PT. Twelve in-scale circular masonry arches were considered, reinforced in various ways at the intrados or at the extrados. GFRP reinforcements were applied either on undamaged or on previously damaged elements, in order to assess the role of external reinforcements even in repairing interventions. The experimental results were critically discussed at the light of limit analysis predictions, based on a 3D FE heterogeneous upper bound approach. Satisfactory agreement was found between experimental evidences and the numerical results, in terms of failure mechanisms and peak load.


2020 ◽  
pp. 713-736
Author(s):  
Magdalena Łaptaś

Images of archangels and angels, which were painted on the walls, in the upper parts of the buildings and, on their structural elements, were very popular in Christian Nubian painting as attested by the discoveries from Church SWN.BV on the citadel in Old Dongola. These images, which derive from pre-Christian art, depict the eternal nature of the archangels and angels. Presenting this group of representations, the author traces the origins of these images to highlight the role of these spiritual beings as intermediaries between God and humankind. As such, they move freely between the Heavens and the Earth, so the air and cosmic space are their natural surroundings. Moreover, archangels govern the forces of nature, the planets, and the seven skies. Therefore, their sanctuaries were located on hill summits, in the upper chapels, on structural elements of ecclesiastical buildings, etc. The Nubian tradition is therefore part of a broader Mediterranean tradition, the roots of which should be sought in the Near East.


Author(s):  
Shijing Wu ◽  
Haibo Zhang ◽  
Xiaosun Wang ◽  
Zeming Peng ◽  
Kangkang Yang ◽  
...  

Backlash is a key internal excitation on the dynamic response of planetary gear transmission. After the gear transmission running for a long time under load torque, due to tooth wear accumulation, the backlash between the tooth surface of two mating gears increases, which results in a larger and irregular backlash. However, the increasing backlash generated by tooth accumulated wear is generally neglected in lots of dynamics analysis for epicyclic gear trains. In order to investigate the impact of backlash generated by tooth accumulated wear on dynamic behavior of compound planetary gear set, in this work, first a static tooth surface wear prediction model is incorporated with a dynamic iteration methodology to get the increasing backlash generated by tooth accumulated wear for one pair of mating teeth under the condition that contact ratio equals to one. Then in order to introduce the tooth accumulated wear into dynamic model of compound planetary gear set, the backlash excitation generated by tooth accumulated wear for each meshing pair in compound planetary gear set is given under the condition that contact ratio equals to one and does not equal to one. Last, in order to investigate the impact of the increasing backlash generated by tooth accumulated wear on dynamic response of compound planetary gear set, a nonlinear lumped-parameter dynamic model of compound planetary gear set is employed to describe the dynamic relationships of gear transmission under the internal excitations generated by worn profile, meshing stiffness, transmission error, and backlash. The results indicate that the introduction of the increasing backlash generated by tooth accumulated wear makes a significant influence on the bifurcation and chaotic characteristics, dynamic response in time domain, and load sharing behavior of compound planetary gear set.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maximilian M. Biebl ◽  
Abraham Lopez ◽  
Alexandra Rehn ◽  
Lee Freiburger ◽  
Jannis Lawatscheck ◽  
...  

AbstractThe co-chaperone p23 is a central part of the Hsp90 machinery. It stabilizes the closed conformation of Hsp90, inhibits its ATPase and is important for client maturation. Yet, how this is achieved has remained enigmatic. Here, we show that a tryptophan residue in the proximal region of the tail decelerates the ATPase by allosterically switching the conformation of the catalytic loop in Hsp90. We further show by NMR spectroscopy that the tail interacts with the Hsp90 client binding site via a conserved helix. This helical motif in the p23 tail also binds to the client protein glucocorticoid receptor (GR) in the free and Hsp90-bound form. In vivo experiments confirm the physiological importance of ATPase modulation and the role of the evolutionary conserved helical motif for GR activation in the cellular context.


2013 ◽  
Vol 13 (01) ◽  
pp. 1350010 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS

Telescopic cranes are usually steel beam systems carrying a load at the tip while comprising at least one constant and one moving part. In this work, an analytical model suitable for the dynamic analysis of telescopic cranes boom is presented. The system considered herein is composed — without losing generality — of two beams. The first one is a jut-out beam on which a variable in time force is moving with constant velocity and the second one is a cantilever with length varying in time that is subjected to its self-weight and a force at the tip also changing with time. As a result, the eigenfrequencies and modal shapes of the second beam are also varying in time. The theoretical formulation is based on a continuum approach employing the modal superposition technique. Various cases of telescopic cranes boom are studied and the analytical results obtained in this work are tabulated in the form of dynamic response diagrams.


2014 ◽  
Vol 104 (5) ◽  
pp. 272-277 ◽  
Author(s):  
Sandile Hlatshwayo ◽  
Michael Spence

This paper examines the underlying structural elements of US growth patterns, pre- and post-crisis. Prior to the recession, the US economy exhibited a defective growth pattern driven by outsized domestic demand. As domestic aggregate demand retreats to more sustainable levels relative to total income, the tradable side of the economy is a catalyst for restoring strong growth. A structural rebalancing is already underway; although it is only a third of the economy, the tradable sector generated more than half of gross gains in value-added since the start of the recovery. However, distributional issues loom on the horizon.


1986 ◽  
Vol 59 (5) ◽  
pp. 740-764 ◽  
Author(s):  
J. Harris ◽  
A. Stevenson

Abstract This paper has discussed the transmissibility behavior of rubber mounts with reference to nonlinearity originating from the material composition and from the geometrical design. It has been shown that in many cases, linear assumptions can be made, provided the limitations of these assumptions are understood. In this case, design can proceed as for a linear spring. Finally, there is some indication of how the nonlinear behavior can be exploited to advantage in the design of novel suspension components.


2020 ◽  
Vol 12 ◽  
pp. 56-66
Author(s):  
E. V. Ryabtseva ◽  

The growing role of the judicial community in reforming the judicial system actualizes the scientific problems of law enforcement associated with understanding the essence of the regulatory impact of the Councils of Judges of the Russian Federation as a body of the judicial community to prevent the emergence of conflicts of legal interests in judicial activity. The purpose of the research is to theoretically substantiate the essence of individual regulation of conflicts of legal interests by the Council of Judges of the Russian Federation, aimed at optimizing its activities to combat corruption. The worldview and methodological basis were the works of theoretical scholars and their methods of integrative understanding of law to substantiate the impact of the Council of Judges of the Russian Federation on judicial activity through individual regulation. The conclusion is substantiated that the activities of the Commission of the Council of Judges of the Russian Federation on Ethics, related to the drawing up of opinions on the assessment of conflicts of legal interests and other corruption risks for both acting judges and retired judges, is an individual regulation of legal relations through: interpretation of law; overcoming gaps and conflicts in the law; individuali zation of rights, etc. The content of the interpretation of law by the Commission of the Council of Judges of the Russian Federation on Ethics is: the application of certain norms of both international and national law in a specific legal relationship when assessing conflicts of legal interests among judges through a systematic interpretation of the norms of law as a system of elements, defining its role in law, identifying other norms, as well as the principles of law; interpretation of the principles and norms of law, through the legal-logical interpretation of a normative act as logically interconnected structural elements of a single, internally agreed and consistent system of principles and norms of law, when deciding on the presence of conflicts of legal interests in the activities of judges, etc. The paper substantiates that in relation to conflicts of legal interests, individualization should be aimed at determining by the Council of Judges of the Russian Federation typical situations of such conflicts for their correct assessment and development of recommendations related to the optimal behavior of judges, when circumstances arise that lead to conflicts of legal interests.


1999 ◽  
Author(s):  
Sungsoo Na ◽  
Liviu Librescu

Abstract A study of the dynamical behavior of aircraft wings modeled as doubly-tapered thin-walled beams, made from advanced anisotropic composite materials, and incorporating a number of non-classical effects such as transverse shear, and warping inhibition is presented. The supplied numerical results illustrate the effects played by the taper ratio, anisotropy of constituent materials, transverse shear flexibility, and warping inhibition on free vibration and dynamic response to time-dependent external excitations. Although considered for aircraft wings, this analysis and results can be also applied to a large number of structures such as helicopter blades, robotic manipulator arms, space booms, tall cantilever chimneys, etc.


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