scholarly journals THE BEHAVIOR UNDER LOAD OF THE PORTAL GANTRY CRANES, REFERING TO STRENGTH, STIFFNESS AND STABILITY PART I – THEORETICAL CONSIDERATIONS

2016 ◽  
Vol 19 (1) ◽  
Author(s):  
GHEORGHE N. RADU ◽  
IOANA COMĂNESCU ◽  
MARIAN POPESCU
Keyword(s):  
Finite Elements ◽  
Point Of View ◽  
Similarity Criteria ◽  
Post Processing ◽  
Elastic Structures ◽  
Basic Study ◽  
Von Mises ◽  
Theoretical Considerations ◽  
Gantry Cranes ◽  
Abaqus Software

The paper’s subject is highly topical, is very interesting from scientific point of view but also very complex. The authors propose to study the elastic structures of the cranes on basis of the similarity criteria, for this purpose the two basis criteria are shortly presented: Hooke and Cauchy. One underlines that the gantry and the half gantry cranes work outside, being subjected to actions as time changing loads; under these circumstances one needs a special check of the crane’s stability. The basic study is that one based on the analysis with finite elements, using ABAQUS software – an advanced software with highly efficient possibilities of modeling. By graphical post processing are presented the equivalent fields of stresses von Mises and of deformations.

scholarly journals Established Numerical Techniques for the Structural Analysis of a Regional Aircraft Landing Gear

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
F. Caputo ◽  
A. De Luca ◽  
A. Greco ◽  
A. Marro ◽  
A. Apicella ◽  
...  
Keyword(s):  
Finite Elements ◽  
Numerical Models ◽  
Three Dimensional ◽  
Landing Gear ◽  
Point Of View ◽  
Fe Model ◽  
One Dimensional ◽  
Reaction Forces ◽  
Local Technique ◽  
Stick Model

Usually during the design of landing gear, simplified Finite Element (FE) models, based on one-dimensional finite elements (stick model), are used to investigate the in-service reaction forces involving each subcomponent. After that, the design of such subcomponent is carried out through detailed Global/Local FE analyses where, once at time, each component, modelled with three-dimensional finite elements, is assembled into a one-dimensional finite elements based FE model, representing the whole landing gear under the investigated loading conditions. Moreover, the landing gears are usually investigated also under a kinematic point of view, through the multibody (MB) methods, which allow achieving the reaction forces involving each subcomponent in a very short time. However, simplified stick (FE) and MB models introduce several approximations, providing results far from the real behaviour of the landing gear. Therefore, the first goal of this paper consists of assessing the effectiveness of such approaches against a 3D full-FE model. Three numerical models of the main landing gear of a regional airliner have been developed, according to MB, “stick,” and 3D full-FE methods, respectively. The former has been developed by means of ADAMS® software, the other two by means of NASTRAN® software. Once this assessment phase has been carried out, also the Global/Local technique has verified with regard to the results achieved by the 3D full-FE model. Finally, the dynamic behaviour of the landing gear has been investigated both numerically and experimentally. In particular, Magnaghi Aeronautica S.p.A. Company performed the experimental test, consisting of a drop test according to EASA CS 25 regulations. Concerning the 3D full-FE investigation, the analysis has been simulated by means of Ls-Dyna® software. A good level of accuracy has been achieved by all the developed numerical methods.

scholarly journals Enzyme catalysis as a chain reaction

1991 ◽  
Vol 279 (3) ◽  
pp. 855-861 ◽  
Author(s):  
S E Szedlacsek ◽  
R G Duggleby ◽  
M O Vlad
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Mechanism ◽  
Point Of View ◽  
Simple Type ◽  
Chain Reaction ◽  
Proposed Model ◽  
New Type ◽  
A Chain ◽  
Theoretical Considerations ◽  
Classical Mechanism

A new type of enzyme kinetic mechanism is suggested by which catalysis may be viewed as a chain reaction. A simple type of one-substrate/one-product reaction mechanism has been analysed from this point of view, and the kinetics, in both the transient and the steady-state phases, has been reconsidered. This analysis, as well as literature data and theoretical considerations, shows that the proposed model is a generalization of the classical ones. As a consequence of the suggested mechanism, the expressions, and in some cases even the significance of classical constants (Km and Vmax.), are altered. Moreover, this mechanism suggests that, between two successive enzyme-binding steps, more than one catalytic act could be accomplished. The reaction catalysed by alcohol dehydrogenase was analysed, and it was shown that this chain-reaction mechanism has a real contribution to the catalytic process, which could become exclusive under particular conditions. Similarly, the mechanism of glycogen phosphorylase is considered, and two partly modified versions of the classical mechanism are proposed. They account for both the existing experimental facts and suggest the possibility of chain-reaction pathways for any polymerase.

Embodiment in Composition: 4E Theoretical Considerations and Empirical Evidence from a Case Study

2020 ◽  
pp. 102986492096144
Author(s):  
Ulla Pohjannoro
Keyword(s):  
Real Life ◽  
Extended Cognition ◽  
Point Of View ◽  
Musical Composition ◽  
Compositional Process ◽  
Musical Notation ◽  
Musical Structures ◽  
Sonic Environment ◽  
Theoretical Considerations

The purpose of this study was to theorise on a composer’s corporeality from the point of view of the embodied, enacted, embedded, and extended cognition paradigm, in the light of empirical data that cover the compositional process of creating one particular piece of music. The data include related manuscripts and the composer’s verbal account of those manuscripts. Composition is seen as an interactive coping behaviour and an adaptive process of knowledge acquisition and production in a sonic environment. In this epistemic process, the composer begins working with various kinds of ideas: sounds, timbres, musical structures, experiences, philosophical thoughts. They explicate these intuitive or reflective embodied representations through different kinds of externalisations, such as musical gestures, narratives, visualisation, and finally, musical notation. This study substantiates the way in which embodied, extrabodily, embedded, and enactive processes constitute the cognitive acts of a composer, usually considered as almost purely mental. It shows how musical composition may not only be grounded but also depend on embodied knowledge that the score only partly conveys. In addition to helping composers and performers communicate in real life, the findings may be useful for identifying the different cognitive premises and circumstances that can result in discrepancies between the ways in which they interpret musical notation.

Static and Dynamic Analysis of Motor Cycle Wheel Designs

2015 ◽  
Vol 813-814 ◽  
pp. 915-920 ◽  
Author(s):  
A. Eswara Kumar ◽  
M. Naga Raju ◽  
Navuri Karteek ◽  
Daggupati Prakash
Keyword(s):  
Vital Role ◽  
Point Of View ◽  
Al Alloy ◽  
Analysis Tool ◽  
Structural Stiffness ◽  
Element Analysis ◽  
Static And Dynamic Analysis ◽  
Wheel Rim ◽  
Strength And Stiffness ◽  
Von Mises

The wheel of a vehicle plays a vital role to bear the load applies on it. Generally spokes acts as the supports between the wheel rim and hub. These spokes must have sufficient strength and stiffness to avoid the failure of the wheel. In present days these wheels are made up of aluminum alloy, magnesium alloy and steel. To reduce the weight of the wheel many wheel designs are implemented and applied for different vehicles. In this paper three different wheel designs are chosen, those are inclined spokes, curved spokes and Y shaped spokes made up of Al alloy, Mg alloy and Steel. Static structural analysis subjected to pressure on the wheel rim and free vibrational analyses are performed by using finite element analysis tool Ansys 12. The objective of the present work is to observe the best design which contains higher structural stiffness, specific structural stiffness with lower von mises stresses under static load conditions. It is observed that curve shaped spoke designs are better in for manufacturing of wheel in both static and dynamic point of view.

Vertical tail FEA with a CAD/CAE based multidisciplinary process

2018 ◽  
Vol 90 (4) ◽  
pp. 652-658
Author(s):  
Péter Deák
Keyword(s):  
Finite Element ◽  
Computer Aided Design ◽  
Tail Length ◽  
Element Model ◽  
Point Of View ◽  
Content Type ◽  
Nodal Displacements ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Aided Design

Purpose The purpose of this paper is to make an analytical comparison of two vertical tail models from a structural point of view. Design/methodology/approach The original vertical tail design of PZL-106BT aircraft was used for Computer aided design (CAD) modeling and for creating the finite element model. Findings The nodal displacements, Von-Mises stresses and Buckling factors for two vertical tail models have been found using the finite element method. The idea of a possible Multidisciplinary concept assessment and design (MDCAD) concept was presented. Practical implications The used software analogy introduces an idea of having an automated calculation procedure within the framework of MDCAD. Originality/value The aircraft used for calculation had undergone a modification in its vertical tail length, as there was an urgent need to calculate for the plane’s manufacturer, PZL Warszawa – Okecie.

A basic study on comprehensive water indices using glass fiber filters and a spectrophotometer

1996 ◽  
Vol 34 (7-8) ◽  
pp. 163-168
Author(s):  
Keigo Nakamura ◽  
Yukihiro Shimatani
Keyword(s):  
Water Quality ◽  
Glass Fiber ◽  
Quality Index ◽  
Point Of View ◽  
Absorbance Spectrum ◽  
Water Color ◽  
Quality Change ◽  
Basic Study ◽  
Water Quality Change ◽  
Water Indices

Chemical and biotic indices of water quality have some problems. They need a lot of time to measure and technology, therefore we considered evaluating water color objectively and quantitatively. This method is as follows; after filtering sampling water on the glass fiber filter, absorbance spectrum of this filter is measured by the spectrophotometer. This method does not need, technology and cost. We surveyed the relation between absorbance spectrum and conventional water indices. As a result, this method is very effective to evaluate water quality change from the water color point of view abd it can also evaluate turbidity and Chlorophyll-a very easily. We expect this method to lead to a new water quality index.

INVERSE DISPERSION RELATION OF BZ-WAVES IN NONSTATIONARY GELS

1999 ◽  
Vol 09 (10) ◽  
pp. 2099-2104 ◽  
Author(s):  
W. HANKE
Keyword(s):  
Dispersion Relation ◽  
Point Of View ◽  
Excitable Media ◽  
Experimental Investigations ◽  
Theoretical Point ◽  
Bz Reaction ◽  
Inverse Dispersion ◽  
Sustained Activity ◽  
System A ◽  
Theoretical Considerations

The behavior of wave propagation, as well that of isolated waves as that of self-sustained activity, in excitable media is characterized by the dispersion relation of the system. For the Belousov–Zhabotinsky (BZ)-reaction as by far the best described system, a number of theoretical considerations and experimental investigations do exist. From the theoretical point of view the dispersion relation of the BZ-reaction has two branches, an upper "fast" or stable branch typified by singular solutions and a lower "slow" branch whose solutions are regular, with a connection between the two branches, defining the smallest possible period and the absolute refractory period of the system. Experimental data are usually located on the upper branch giving higher propagation velocity at increasing period. Only one set of results was published in the early 1970s with velocity being an increasing function of frequency. This set of data was stated to be "difficult to believe" in later papers. We now present here a more detailed study of a BZ-system with a dispersion relation with an increasing velocity at decreasing period, verifying the existence of an "inverse" dispersion relation at least in the nonstationary gels we have used.

Gedanken zum Verhältnis zwischen christlichen Apokryphen und hagiographischer Literatur: Das Beispiel der Veronica-Traditionen

2008 ◽  
Vol 62 (1) ◽  
pp. 45-63
Author(s):  
Tobias Nicklas
Keyword(s):  
Point Of View ◽  
Text Interpretation ◽  
The Cross ◽  
The Relationship ◽  
Theoretical Considerations ◽  
Apocryphal Texts

The article deals with the relationship between Christian apocryphal texts and hagiographic texts. It starts with theoretical considerations about the meaning of text interpretation. Their result is that it should not be asked whether a text is ‘apocryphal’ or ‘hagiographic’, but whether it can be interpreted ‘reasonably’ as apocryphal or hagiographic literature. Thus, one and the same text can be understood reasonably from one point of view as apocryphal, and from another point of view as hagiographic. Those theoretical thoughts are illustrated with the analysis of the figure of ‘Veronica’ in the Acts of Pilate, the so called Mors Pilati, as well as in the Sixth Station of the Cross.

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