Name: couple moment in force systems
Uploaded: 2023-09-22T11:49:21.000Z
Duration: 1 min 29 s
Channel: JoVE

Un par es un par de fuerzas paralelas que tienen magnitudes iguales pero que actúan en direcciones opuestas, separadas por una distancia perpendicular.
El par provoca una fuerza de rotación que hace girar el cuerpo alrededor de un eje perpendicular al plano de las fuerzas, y el momento resultante se conoce como momento de pareja.
Considere apretar un perno con una llave de tuercas. Un par de fuerzas se forma cuando se aplican dos fuerzas iguales y opuestas sobre la llave en los puntos A y B, separadas por una distancia perpendicular.
Los vectores de posición rA y rB se dirigen desde el origen de un sistema de coordenadas hasta los puntos de aplicación.
El momento de pareja alrededor del origen es la suma del producto cruzado de los vectores de posición y las fuerzas.
La diferencia entre los vectores de posición rA y rB es el vector de posición r, que es la distancia entre las dos fuerzas opuestas.
El momento de acoplamiento solo depende del vector de posición r entre las fuerzas y no de los vectores de posición rA y rB. Por lo tanto, se considera un vector libre.

<ol>
	<li>Hibbeler, R.C. (2016). Ingeniería Mecánica \u2012 Estática y Dinámica. Hoboken, Nueva Jersey: Pearson Prentice Hall. págs. 154</li>
	<li>Cerveza, F.P.; Johnston, E.R.; Mazurek, D.F.; Cromwell, P.J. y Self, B.P. (2019). Mecánica vectorial para ingenieros: estática y dinámica. Nueva York: McGraw-Hill. Págs. – 120.</li>
</ol>

par de fuerzas

Un par de fuerzas es un par de fuerzas paralelas de igual magnitud pero en direcciones opuestas. Las fuerzas están separadas por una distancia perpendicular, conocida como el brazo del par. El par de fuerzas genera un momento de rotación que gira el cuerpo alrededor de un eje perpendicular al plano de las fuerzas. El momento resultante se denomina momento del par. La unidad SI de un momento del par es el Newton-metro (N-m). Un ejemplo típico para entender este concepto es apretar un perno con una llave de dado. Se forma un par de fuerzas cuando se aplican dos fuerzas iguales y opuestas a la llave en los puntos A y B separados por una distancia perpendicular. Los vectores de posición respectivos están dirigidos desde el origen de un sistema de coordenadas hasta el punto de aplicación. El momento del par sobre el origen es la suma del producto cruzado de los vectores de posición y las fuerzas. La diferencia entre los vectores de posición de las dos fuerzas opuestas da el vector de posición r, que es la distancia entre las fuerzas opuestas. Interesantemente, el momento del par solo depende del vector de posición r entre las fuerzas, no de los vectores de posición individuales de las dos fuerzas. El vector de posición r es independiente del origen. Esto implica que calcular los momentos de las mismas fuerzas alrededor de un punto diferente daría el mismo resultado. El momento del par es un vector libre. A diferencia del momento del par, el momento de una fuerza depende de la posición en la que se mide. Si dos pares de fuerzas producen un momento de igual magnitud y dirección, entonces estos dos pares son equivalentes. Los pares equivalentes tienen el mismo efecto de torsión o de giro independientemente de sus posiciones, direcciones o magnitudes. Calcular el momento del par y comprender sus efectos es crucial en el diseño de sistemas estables y robustos que puedan resistir fuerzas externas.

Par de fuerzas

Un par es un par de fuerzas paralelas iguales en magnitud pero en direcciones opuestas. Las fuerzas están separadas por una distancia perpendicular, conocida como ...

Education

Educación

JoVE Core

Mechanical Engineering

Ingeniería Mecánica

Unit 1

Unidad 1

Force System Resultants

Resultantes de Sistemas de Fuerzas

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Couple

couple moment in force systems

A couple is a pair of parallel forces that are equal in magnitude and opposite in direction. The two forces are separated by a perpendicular distance called the couple arm. Together, they create a turning effect on a body instead of a net push.

This turning effect is called the couple moment. It rotates the body about an axis that is perpendicular to the plane of the forces. The SI unit for a couple moment is the Newton-meter (N-m).

A common example is tightening a bolt with a lug wrench. In that case, two equal and opposite forces act at points A and B on the wrench. These points are separated by a perpendicular distance, so they form a force couple.

The couple moment about the origin is found by adding the cross products of the position vectors and the forces. The position vector between the two opposing forces is r, which is the distance between them. The couple moment depends only on this vector r, not on the separate position vectors of the forces.

Because r does not depend on the origin, the same couple moment is obtained even if the moments are taken about a different point. This is why a couple moment is a free vector. A moment of a single force is different because it depends on where it is measured.

If two couples create moments with the same magnitude and direction, they are equivalent couples. Equivalent couples have the same torque, or turning effect, even if their positions, directions, or magnitudes differ. Understanding couple moments helps in designing stable systems that can resist external forces.

Couple Moment in Force Systems

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couple

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key terms and concepts

Learn how a couple creates rotation, why couple moment depends on the distance between forces, and how equivalent couples are identified in force systems.

Couple Moment in Force Systems | JoVE K12

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mechanical engineering

Couple Moment in Force Systems

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