Name: forces that bend and twist materials
Uploaded: 2025-05-22T09:06:03.000Z
Duration: 1 min 20 s
Channel: JoVE

Das Biegemoment ist definiert als die Reaktion, die in einem Strukturelement entsteht, wenn es einer äußeren Kraft ausgesetzt wird, die dazu führt, dass sich das Element verbiegt.
Wenn ein Strukturelement gebogen wird, erzeugt es Drucknormalkräfte an der Oberseite und Zugnormalkräfte an der Unterseite, was zu einem Paar führt, das das Biegemoment des Elements bestimmt.
Das Biegen eines an einem Ende befestigten Lineals, eines Sprungbretts und des Stabhochsprungs sind einige Beispiele für Biegemomente.
Ein Torsionsmoment tritt auf, wenn eine Verdrehungskraft entlang seiner Querachse auf einen Körper ausgeübt wird, wodurch sich der Abschnitt verdreht.
Das Drehen von Kleidung, das Eindrehen von Schrauben und Torsionsfedern sind einige Beispiele für Torsionsmomente.
Die Schnittgrößen und Kopplungsmomente, die auf einen Querschnitt eines Balkens wirken, können durch ihre x-, y- und z-Komponenten dargestellt werden.
Das Torsionsmoment My wird in y-Richtung dargestellt, während Mx und Mz die Biegemomentkomponenten in x- und z-Richtung darstellen.

<ol>
	<li>Hibbeler, RC (2016) Technische Mechanik: Statik und Dynamik Hoboken, New Jersey: Pearson Prentice Hall, S. 344-345.</li>
	<li>Meriam, J.L.; Kraige, LG und Bolton, J.N. (2020). Technische Mechanik \u2012 Statik. Hoboken, New Jersey: John Wiley. Seite 276.</li>
</ol>

biege- und torsionsmomente

Bending and Torsional Moments

Biege- und Torsionsmomente sind zwei grundlegende Konzepte im Bauingenieurwesen. Sie spielen eine wichtige Rolle beim Verständnis des Verhaltens von Materialien und Strukturen unter verschiedenen Belastungsbedingungen. Die Reaktion, die sich in einem Bauelement entwickelt, wenn es einer externen Kraft ausgesetzt wird, führt zu einer Biegung des Elements. Wenn ein Bauelement nach oben biegt, erzeugt es Drucknormalkräfte auf der Oberseite und Zugnormalkräfte auf der Unterseite, was zu einem Moment führt, das als Biegemoment des Elements bezeichnet wird. Dieses Moment wird berechnet, indem der Abstand von dem betrachteten Punkt zur Wirkungslinie der Kraft und die Größe der Kraft berücksichtigt werden. Das Biegen eines Lineals, das an einem Ende fixiert ist, ist ein Beispiel für ein Biegemoment. Wenn eine Kraft senkrecht zum Lineal nahe dem ungestützten Ende nach unten aufgebracht wird, verursacht sie eine Biegung im Lineal. Die aufgebrachte Kraft erzeugt ein Moment um das feste Ende herum, wodurch das Lineal gebogen oder verformt wird. In diesem Szenario wird das Lineal sowohl Druck- als auch Zugkräften ausgesetzt sein. Die Oberseite des Lineals, die von der aufgebrachten Kraft weg zeigt, wird unter Zugspannung stehen. Die Unterseite, die auf die aufgebrachte Kraft zugeht, wird unter Druck stehen. Ein Torsionsmoment tritt auf, wenn eine Verdrehung auf einen Körper entlang seiner quer oder längs verlaufenden Achse ausgeübt wird, was zu einer Verdrehung des Querschnitts führt. Diese Verdrehungskraft erzeugt einen inneren Widerstand im Material, der der aufgebrachten Kraft entgegenwirkt. Das Torsionsmoment wird als das Produkt aus der Verdrehungskraft und dem Abstand von dem betrachteten Punkt zur Wirkungslinie der Kraft berechnet. Wenn man eine Schraube mit einem Schraubendreher oder einem Bohrer in ein Material schraubt, wird ein Torsionsmoment auf die Schraube ausgeübt, während sie sich dreht und auf Widerstand des Materials trifft. Die Drehkraft, die vom Schraubendreher oder Bohrer erzeugt wird, lässt die Schraube rotieren, und der Widerstand des Materials erzeugt eine entgegenwirkende Kraft, die ein Torsionsmoment erzeugt.

Biege- und Torsionsmomente

Biege- und Torsionsmomente sind zwei grundlegende Konzepte im konstruktiven Ingenieurbau. Sie spielen eine wichtige Rolle beim Verständnis des Verhaltens von ...

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forces that bend and twist materials

Bending and torsional moments describe how materials respond to force. These ideas are important in structural engineering because they help explain how beams, rulers, and screws change shape under load. A moment depends on both the size of the force and the distance from the point of interest to the force’s line of action.

A bending moment forms when an external force makes a structural element bend. If the element bends upward, the top side is in compression and the bottom side is in tension. These opposite forces create a couple that determines the bending moment. A ruler fixed at one end shows this effect when a downward force is applied near the free end.

In that ruler example, the force acts perpendicular to the ruler and causes it to deform around the fixed end. The side facing away from the applied force is in tension, and the side facing toward the force is in compression. This makes the bending moment easy to see in a simple everyday object.

A torsional moment happens when a twisting force is applied along a body’s transverse or longitudinal axis. The material resists that twist, so an internal force develops inside it. A screwdriver or power drill turning a screw shows torsion in action. As the screw rotates and meets resistance from the material, the twisting force and the opposing resistance create the torsional moment.

Forces That Bend and Twist Materials

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bending and torsional moments

Bending and torsional moments describe how materials respond to force. These ideas are important in structural engineering because they help explain how beams, rulers, and screws change shape under load. A moment depends on both the size of the force and the distance from the point of interest to the force’s line of action. A bending moment forms when an external force makes a structural element bend. If the element bends upward, the top side is in compression and the bottom side is in tension.

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key terms and concepts

Explore how bending and torsional moments act on materials, from a ruler bending at one end to a screw twisting under a screwdriver.

Forces That Bend and Twist Materials | 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.

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Forces That Bend and Twist Materials

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