Name: lifting tong force analysis
Uploaded: 2023-09-22T11:49:25.000Z
Duration: 1 min 30 s
Channel: JoVE

Considere uma pinça de elevação carregando uma carga de 100 kg. É composto por seções móveis DAF e CBG ligadas entre si com o membro AB.
Supondo que a estrutura seja simétrica em relação ao ponto E, que força está agindo no membro AB?
Um diagrama de corpo livre indicando as forças que atuam no ponto E é desenhado.
A força de tensão do cabo equilibra o peso da carga e atua verticalmente para cima.
ED e EC são membros de duas forças. Assim, as forças FED e FEC são direcionadas para as articulações D e C, respectivamente.
Essas forças são resolvidas em componentes horizontais e verticais, e a geometria da estrutura é aplicada para determinar o ângulo entre o membro ED e o componente de força horizontal.
A aplicação da condição de equilíbrio de força ao longo da direção horizontal garante que FED seja igual a FEC.
Da mesma forma, a condição de equilíbrio de força vertical produz a força ao longo do membro ED.
Agora, considere um diagrama de corpo livre para a seção DAF. A condição de equilíbrio de momento pode ser aplicada à junta F. 
Substituindo todos os valores conhecidos na equação, obtém-se a força ao longo da barra AB.

<ol>
	<li>Hibbeler, R.C. (2016). Engenharia Mecânica \u2012 Estática e Dinâmica. Hoboken, Nova Jersey: Pearson Prentice HallPppp 305.</li>
	<li>Cerveja, F.P.; Johnston, E.R.; Mazurek, D.F; Cromwell, PJ e Self, BP (2019). Mecânica vetorial para engenheiros \u2012 estática e dinâmica. Nova Iorque: McGraw-Hill. pág. 348</li>
	<li>Meriam, J.L., Kraige, L.G., e Bolton, J.N. (2020). Engenharia Mecânica \u2012 Estática. Hoboken, Nova Jersey: John Wiley. pág. 200</li>
</ol>

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máquinas: resolução de problemas ii

As máquinas são estruturas complexas, consistindo de membros móveis e pinos conectados que trabalham juntos para transmitir forças. Considere uma tenaz de levantamento carregando uma carga de 100 kg. Ela é composta por seções móveis DAF e CBG, ligadas juntas com o membro AB.

<img alt="Figure 1" src="/files/ftp_upload/14295/14295_PT_Fig_1v2.svg" style="text-align: center; height: 350px;" />

Assumindo que a estrutura é simétrica no ponto E, a força atuando no membro AB pode ser calculada.

Primeiro, um diagrama de corpo livre indicando as forças atuando no ponto E é considerado. O peso da carga, que é igual à massa multiplicada pela aceleração da gravidade, é calculado como 981 N. A força de tensão do cabo equilibra o peso da carga e atua verticalmente para cima. ED e EC são membros de duas forças. Como resultado, as forças FED e FEC são direcionadas para as juntas D e C, respectivamente.

Em seguida, as forças FED e FEC são resolvidas em componentes horizontais e verticais. A geometria da estrutura pode calcular o ângulo entre o membro ED e o componente da força horizontal como 30,96 graus.

As condições de equilíbrio de força podem ser aplicadas à junta E.

<img alt="Equation 1" src="/files/ftp_upload/14295/14295_PT_Equation_1v2.svg" style="text-align: center; height: 13px;" />

<img alt="Equation 2" src="/files/ftp_upload/14295/14295_PT_Equation_2v2.svg" style="text-align: center; height: 13px;" />

Aplicar a condição de equilíbrio de força na direção horizontal garante que FED seja igual a FEC. Da mesma forma, a condição de equilíbrio de força vertical produz a força ao longo do membro ED como 953,46 N.

Agora, um diagrama de corpo livre para a seção DAF é considerado. A condição de equilíbrio de momento pode ser aplicada à junta F.

O resultado dá a força ao longo do membro AB como 2423,76 N.

<img alt="Equation 3" src="/files/ftp_upload/14295/14295_PT_Equation_3v2.svg" style="text-align: center; height: 13px;" />

Compreender as forças atuando em cada membro neste sistema de tenaz de levantamento é essencial para garantir uma operação segura e projetar mecanismos de elevação eficientes. Ao analisar as forças e aplicar as condições de equilíbrio, os engenheiros podem otimizar a estrutura e garantir que ela possa carregar cargas com segurança em várias condições.

Máquinas: Resolução de Problemas II

As máquinas são estruturas complexas que consistem em membros multi-força móveis conectados por pinos que trabalham juntos para transmitir forças. Considere uma pinça de elevação ...

Education

JoVE Core

Mechanical Engineering

Engenharia Mecânica

Unit 1

Unidade 1

Structural Analysis

Análise Estrutural

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

Machines: Problem Solving II

lifting tong force analysis

Lifting tong force analysis shows how forces move through a pin-connected machine. The structure uses movable sections DAF and CBG with member AB linking them together. Because these parts work as connected members, the load can be studied with equilibrium methods.

The example starts with a 100 kg load at point E. The load weight is found by multiplying mass by gravity, which gives 981 N. The cable tension acts upward and balances that weight. Since the structure is symmetrical at E, the forces on the two sides can be compared.

Members ED and EC are two-force members, so their forces act along the members toward joints D and C. Their forces are then split into horizontal and vertical parts. Using the geometry of the tong, the angle between member ED and the horizontal is 30.96 degrees. Force equilibrium at joint E shows that F ED equals F EC, and the vertical balance gives the force in member ED as 953.46 N.

After that, a free-body diagram for section DAF is used. The moment equilibrium condition is applied at joint F. This step gives the force in member AB as 2423.76 N. This kind of analysis helps engineers check the forces in each member so lifting systems can work safely and efficiently under load.

Lifting Tong Force Analysis

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machines: problem solving ii

Lifting tong force analysis shows how forces move through a pin-connected machine. The structure uses movable sections DAF and CBG with member AB linking them together. Because these parts work as connected members, the load can be studied with equilibrium methods. The example starts with a 100 kg load at point E. The load weight is found by multiplying mass by gravity, which gives 981 N. The cable tension acts upward and balances that weight. Since the structure is symmetrical at E, the...

key terms and concepts

Analyze a lifting tong with pin-connected members, symmetry, and equilibrium. See how force, tension, and moments determine the load on member AB.

Lifting Tong Force Analysis | JoVE K12

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Lifting Tong Force Analysis

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