Pratique du Shadowing: How Shear Deflection Impacts Deep and Composite Beams. - Apprendre l'anglais à l'oral avec la vidéo

Création de la leçon...
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Welcome back to the channel.
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In today's video, we will be discussing the representation of frames by elements along the centerlines of their members,
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as well as the concept of shear deflection in beam deflection calculations.
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We will be exploring two specific examples, introducing a short, stiff horizontal member in a column connection
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and offsetting a smaller beam within the depth of a larger beam we will also be discussing composite frame analysis
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and the properties of composite sections transformed into equivalent steel sections
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finally we will delve into the effect of shear deflection on
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beam deflection including its importance in situations where beams are deep
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or in composite construction let's start by discussing the representation of frames by elements along the center lines of their members.
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Situations with discontinuities can arise as illustrated.
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One example is the introduction of a short, stiff horizontal member in the column connection, which may be rigidly connected,
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pinned at either end or centrally hinged.
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The choice of pin position affects the resulting bending moment's location and size, and it should be reflected in the connection design between the two sections.
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In many cases, designing the lower column for an additional bending moment
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and a nominally pinned connection from the upper column is appropriate.
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The second example involves the offset of a smaller beam within the depth of a larger beam.
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If the smaller beam remains within the larger beam's depth, it is not necessary to model the offset, provided that any actual loaves in the beams are small.
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Next, composite frame analysis.
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Composite frame analysis is typically done by considering a subframe,
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and the properties of composite sections must be transformed into an equivalent steel section.
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The redistribution of moments may depend on the method of analysis and section classification at the support.
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Figure 1 shows a suitable subframe for composite frame analysis,
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and figure 2 illustrates the relationship between composite section properties and steel section weight for initial analysis.
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Now let's talk about the concept of shear deflection, which occurs in addition to bending deflection as a result of shear strain in an element.
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The engineer's theory of bending commonly used to calculate deflections by hand ignores shear deflection.
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Neglecting shear deflection in beam deflection calculations is acceptable for non -composite beams of typical proportions used in conventional floors.
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However, in situations where beams are deep or in composite construction,
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shear deflection becomes a more significant proportion of the overall deflection.
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The deflection of castellated and cellular beams also includes a relatively large component due to the action of shear.
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If truss or virundial frames are modelled by beam elements in preparing scheme calculations,
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shear deflection must be included in deflection calculations because in this case it is a significant proportion of the total.
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Shear deflection will be taken into account in an analysis
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if the beam element used in modeling the structure is formulated to do so.
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The effect of shear deflection becomes more significant as beams become stocky or have a small span depth ratio.
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The following table shows the additional deflection due to shear as
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a percentage of the deflection due to bending for simply supported and cantilever eye section members.
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The contribution of shear deflection to the total deflection becomes important only in the case of stocky members
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and it is inversely proportional to the square of the span depth ratio.
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Plate girders typically have span depth ratios between 8 and 15,
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while span depth ratios for universal sections in building construction are around 20.
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At small span depth ratios, shear deflection may exceed deflection due to bending, but both are likely to be small.
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We hope you found this video informative and helpful.
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If you have any questions or comments, please leave them in the comments section below.
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Don't forget to hit the like button and subscribe to our channel for more informative videos.
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Thanks for watching, and we'll see you in the next one.

Vocabulaire et conseils d’expression pour cette leçon

Cette leçon d’expression orale de niveau C1 s’appuie sur la vidéo « How Shear Deflection Impacts Deep and Composite Beams ». Les mots qui reviennent le plus souvent : deflection, beam, shear, section, composite. Cette vidéo contient 45 phrases et 653 mots à répéter en shadowing. La partie parlée dure 4:43. Le locuteur parle à un rythme régulier d’environ 138 mots par minute, confortable pour le shadowing. Seuls 70 % des mots font partie des 3 000 mots les plus courants en anglais, le vocabulaire est donc exigeant.

Vocabulaire clé de cette vidéo

Les 15 mots les plus avancés de la vidéo, avec leur prononciation et leur sens :

MotPrononciationSens
deflection nom/dəˈflɛkʃən/déflexion
shear verbe/ʃɪɚ/tondre
calculation nom/ˌkælkjuˈleɪʃn̩/calcul
offset nom/ˈɔf.sɛt/compensation
stocky adjectif/ˈstɑki/trapu
informative adjectif/ɪnˈfɔːmətɪv/instructif, informatif
illustrate verbe/ˈɪl.əˌstɹeɪt/illustrer
stiff adjectif/stɪf/rigide, raide
horizontal adjectif/ˌhoɹəˈzɑn.təl/horizontal
transform verbe/tɹænsˈfɔɹm/transformer
cantilever nom/ˈkantɪliːvə/porte-à-faux
centrally adverbe/ˈsɛnt.ɹə.li/centralement
formulate verbe/ˈfɔː(ɹ)mjʊleɪt/formuler
girder nom/ˈɡɝdɚ/poutrelle
inversely adverbeinversement

Prononciation à surveiller

  • Les sons « sh » et « zh »: deflection /dəˈflɛkʃən/, shear /ʃɪɚ/, calculation /ˌkælkjuˈleɪʃn̩/, redistribution /ˌɹiːdɪstɹəˈbjuːʃən/
  • Mots longs — placez bien l’accent: informative /ɪnˈfɔːmətɪv/, horizontal /ˌhoɹəˈzɑn.təl/, cantilever /ˈkantɪliːvə/, castellated /ˈkastəleɪtɪd/, discontinuity /ˌdɪs.kɑn.tɪˈnu.ɪ.ti/

Les sons difficiles pour les francophones :

  • /r/ anglais — langue recourbée, sans frotter la gorge: illustrate /ˈɪl.əˌstɹeɪt/, horizontal /ˌhoɹəˈzɑn.təl/, transform /tɹænsˈfɔɹm/, centrally /ˈsɛnt.ɹə.li/, formulate /ˈfɔː(ɹ)mjʊleɪt/

Comment s’entraîner avec cette vidéo

  1. Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
  2. Répétez phrase par phrase à vitesse normale, en reprenant chacune jusqu’à ce que votre rythme corresponde à celui du locuteur.
  3. Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme deflection, shear, calculation.

Qu'est-ce que la technique du Shadowing ?

Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.

Technique du shadowing : lire le guide complet étape par étape →