Name: load distribution on shelves and dams
Uploaded: 2023-09-22T11:49:22.000Z
Duration: 1 min 19 s
Channel: JoVE

Une charge distribuée est un type de charge qui est répartie sur une surface ou une structure.
Prenons l’exemple d’une étagère composée de livres. Le poids des livres est réparti uniformément sur la surface.
La pression à différents endroits de la surface correspond à la charge appliquée sur la surface et est mesurée en Newton par mètre carré ou en Pascals.
Considérons un barrage hydroélectrique, dont la surface immergée est modélisée sous la forme d’une plaque rectangulaire.
Pour un petit élément de longueur dx, la force exercée sur l’élément peut être exprimée sous la forme d’une charge distribuée donnée par wdx.
En intégrant la force exercée sur l’élément, on détermine la charge totale, qui est égale en amplitude à l’aire totale sous la courbe de charge, et sa ligne d’action passe par le centroïde de l’aire.
Le point où la force résultante est appliquée est connu sous le nom de centre de pression.

<ol>
	<li>Hibbeler, R.C. (2016). Génie mécanique \u2012 Statique et dynamique. Hoboken, New Jersey : Pearson Prentice Hall. page 190</li>
	<li>Bière, F.P. ; Johnston, E.R. ; Mazurek, D.F ; Cromwell, P.J. et Self, B.P. (2019). Mécanique vectorielle pour les ingénieurs \u2012 Statique et dynamique. New York : McGraw-Hill. p. 262.</li>
</ol>

charges réparties

Distributed Loads

Les charges réparties sont un type courant de charges auxquelles les ingénieurs et les scientifiques sont confrontés dans diverses situations pratiques. Les charges réparties se réfèrent souvent à un type de charge répartie sur une surface ou une structure et peuvent être modélisées comme une force continue par unité de surface. Par exemple, prenons une étagère remplie de livres empilés verticalement les uns à côté des autres. Le poids des livres est réparti uniformément sur la longueur de l'étagère. En conséquence, la pression à différents endroits sur la surface de l'étagère correspond à la charge appliquée et est mesurée en newtons par mètre carré, ou en pascals. En termes d'une autre application, prenons un barrage hydroélectrique, pour lequel la surface immergée est modélisée comme une plaque rectangulaire. La force exercée sur un petit élément de la plaque de longueur dx peut être exprimée comme la charge répartie, donnée par wdx, où "w" est la force par unité de surface. La charge totale appliquée à la plaque peut être déterminée en intégrant la force exercée sur chaque petit élément. La magnitude de la force résultante exercée sur la plaque est proportionnelle à la surface sous la courbe de charge, et sa ligne d'action passe par le centre de gravité de la surface. Ce point est connu sous le nom de centre de pression. Le centre de pression est essentiel pour concevoir des structures capables de résister aux forces externes. Des exemples de charges réparties incluent les charges de neige sur le toit d'un bâtiment, les charges de vent agissant sur une structure, ou même le poids d'une voiture sur un pont. Comprendre les charges réparties est crucial pour concevoir des structures sûres et robustes capables de résister aux forces externes.

Charges réparties

Les charges distribuées sont un type de charge courant que les ingénieurs et les scientifiques rencontrent dans diverses situations pratiques. Les charges réparties font souvent référence à un ...

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load distribution on shelves and dams

Load distribution helps engineers describe how force spreads across a surface or structure. A distributed load is a continuous force per unit area, rather than a single point force. It is a common idea in many practical situations.

A bookshelf full of stacked books is one simple example. The weight of the books is spread along the shelf, so the pressure changes across the surface. This pressure is measured in Newtons per square meter, or Pascals.

A hydroelectric dam gives another clear example. The submerged surface can be modeled as a rectangular plate. The force on a small piece of that plate, with length dx, is written as wdx, where w is the force per unit area.

The total load on the plate is found by integrating the force from each small element. The size of the resultant force is related to the area under the load curve. Its line of action passes through the centroid of that area. This point is called the center of pressure, and it is important for designing structures that can resist external forces.

Distributed loads also appear in many other situations. Snow on a roof, wind on a structure, and the weight of a car on a bridge are all examples. Understanding these loads helps engineers build safe and robust structures.

Load Distribution on Shelves and Dams

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key terms and concepts

Learn how distributed loads spread force across shelves, dams, roofs, and bridges, and how engineers use integration and the center of pressure to design safe structures.

Load Distribution on Shelves and Dams | JoVE K12

JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

mechanical engineering

Load Distribution on Shelves and Dams

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