Name: truss member force analysis by sections
Uploaded: 2025-05-22T09:06:03.000Z
Duration: 1 min 30 s
Channel: JoVE

Considere una estructura de celosía arbitraria que consta de miembros diagonales, verticales y horizontales fijados a la pared.
El método de las secciones se puede utilizar para calcular la fuerza que actúa sobre las barras CB, GB y GH.
Aquí, las cargas y las longitudes de las barras horizontales y verticales son los parámetros conocidos.
Se realiza un corte a lo largo de un plano que intersecta las barras CB, GB y GH y se dibuja un diagrama de cuerpo libre de la sección del lado derecho.
La ecuación de equilibrio de momento alrededor del punto G da la fuerza a lo largo de CB. El signo positivo indica tensión en la barra. 
Ahora, FGB se puede expresar usando un triángulo de pendiente en BCG, mientras que FGH se puede expresar usando un triángulo de pendiente en CEG.
Considerando la suma de fuerzas verticales y horizontales, se pueden escribir las ecuaciones de equilibrio de fuerzas.
Se sustituye el valor de FCB y se resuelven simultáneamente las ecuaciones de equilibrio de fuerzas para obtener la fuerza a lo largo de los miembros GH y GB.
El signo negativo de FGH indica que la fuerza es de compresión, mientras que el signo positivo de FGB indica la fuerza de tracción.

<ol>
	<li>R. C., Hibbeler Engineering Mechanics Statics, Pearson. págs. 291-293</li>
	<li>F.P. Beer, E.R. Johnston, D.F. Mazurek, P.J. Cornwell, B.P. Self, Mecánica Vectorial para Ingenieros Estática y Dinámica Mecánica de Ingeniería Estática, Mc Graw-Hill Educación. Págs. 217</li>
</ol>

No se han declarado conflictos de interés.

método de secciones: resolución de problemas ii

Considere una estructura de cercha arbitraria compuesta por miembros diagonales, verticales y horizontales fijados a la pared. Para calcular la fuerza actuando sobre los miembros CB, GB y GH, se puede utilizar el método de secciones. Las cargas y longitudes de los miembros horizontales y verticales son parámetros conocidos, como se muestra en la figura.

<img alt="Figure 1" src="/files/ftp_upload/14287/14287_PT_Fig_1v2.svg" style="text-align: center; height: 350px;"> 

Para comenzar, se realiza un corte a lo largo de un plano que interseca los miembros CB, GB y GH, y se dibuja un diagrama de cuerpo libre de la sección del lado derecho.

<img alt="Figure 2" src="/files/ftp_upload/14287/14287_PT_Fig_2v2.svg" style="text-align: center; height: 350px;"> Se aplica la ecuación de equilibrio de momento sobre el punto G. <img alt="Equation 1" src="/files/ftp_upload/14287/14287_PT_Equation_1v2.svg" style="text-align: center; height: 13px;"> El resultado da la fuerza a lo largo del miembro CB como 4 kN, con un signo positivo que indica tensión en el miembro. Ahora, FCB se puede expresar utilizando un triángulo de pendiente en BCG, mientras que FGH se puede expresar utilizando un triángulo de pendiente en CEG. Considerando la suma de las fuerzas verticales y horizontales, las ecuaciones de equilibrio de fuerzas se pueden escribir de la siguiente manera: <img alt="Equation 2" src="/files/ftp_upload/14287/14287_PT_Equation_2v2.svg" style="text-align: center; height: 15px;"> <img alt="Equation 3" src="/files/ftp_upload/14287/14287_PT_Equation_3v2.svg" style="text-align: center; height: 13px;"> Se sustituye el valor de FCB y se resuelven simultáneamente las ecuaciones de equilibrio de fuerza. El resultado arroja una fuerza FGH de -7.454 kN y una fuerza FGB de 3.772 kN. El signo negativo de FGH indica que la fuerza es de compresión, mientras que el signo positivo para FGB indica una fuerza de tensión.

Método de secciones: Resolución de problemas II

Considere una estructura de celosía arbitraria compuesta por miembros diagonales, verticales y horizontales fijados a la pared. Para calcular la fuerza que actúa sobre los miembros ...

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Method of Sections: Problem Solving II

truss member force analysis by sections

Truss member force analysis by sections finds the forces in selected members of a wall-mounted truss. The structure here includes diagonal, vertical, and horizontal members. The known loads and member lengths are used to solve for the forces in CB, GB, and GH.

A cut is made through members CB, GB, and GH. The right side of the truss is then isolated as a free-body diagram. Next, the moment equilibrium equation is taken about point G. This step gives the force in member CB as 4 kN, and the positive sign shows that CB is in tension.

The force in CB is then written with a slope triangle in triangle BCG. The force in GH is written with a slope triangle in triangle CEG. After that, the sums of vertical and horizontal forces are set equal to zero. The equation for CB is substituted, and the remaining equations are solved at the same time.

The final values are FGH = -7.454 kN and FGB = 3.772 kN. The negative sign for GH means the member is in compression. The positive sign for GB means the member is in tension.

Truss Member Force Analysis by Sections

truss-force-analysis-using-method-of-sections

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Truss member force analysis by sections finds the forces in selected members of a wall-mounted truss. The structure here includes diagonal, vertical, and horizontal members. The known loads and member lengths are used to solve for the forces in CB, GB, and GH. A cut is made through members CB, GB, and GH. The right side of the truss is then isolated as a free-body diagram. Next, the moment equilibrium equation is taken about point G. This step gives the force in member CB as 4 kN, and the...

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key terms and concepts

Learn how the method of sections isolates a truss cut, uses moment and force balance, and identifies tension or compression in members CB, GB, and GH.

Truss Member Force Analysis by Sections | 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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Truss Member Force Analysis by Sections

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