Name: forces inside a body and balance
Uploaded: 2023-09-22T11:49:22.000Z
Duration: 1 min 25 s
Channel: JoVE

Las fuerzas internas se generan dentro de un cuerpo debido a la interacción entre sus partículas. Estas fuerzas incluyen tensión, compresión y cizallamiento. 
Las fuerzas internas existen en pares colineales de igual magnitud pero en direcciones opuestas. Se cancelan entre todas las partes conectadas, lo que resulta en el equilibrio del cuerpo.
El peso de un cuerpo es una fuerza externa representada por una sola fuerza resultante que actúa a través del centro de gravedad del cuerpo.
Es el punto en el que un cuerpo se equilibra a sí mismo, siempre que ninguna fuerza externa actúe sobre él.
Un cuerpo simétrico o uniforme tiene su centro de gravedad en su centro geométrico. Sin embargo, para un cuerpo irregular o no uniforme, está descentrado hacia el lado más pesado.
Considere una viga unida a una grúa en el centro, con cargas conectadas en sus extremos. Si la carga en un lado se vuelve pesada, el centro de gravedad se alejará de la línea central de la viga, lo que podría causar un vuelco.
El centro de gravedad debe estar identificado para garantizar la estabilidad, y el gancho de elevación debe colocarse directamente encima de él.

<ol>
	<li>Russell C. Hibbeler. (2016). Ingeniería Mecánica: Estática y Dinámica. Pearson. Págs. 212.</li>
</ol>

fuerzas internas y centro de gravedad

Internal Forces and Center of Gravity

Las fuerzas internas y el centro de gravedad son conceptos fundamentales en la mecánica, desempeñando un papel crucial en la comprensión del comportamiento y la estabilidad de estructuras y objetos bajo diversas condiciones. Una comprensión exhaustiva de estos principios es esencial para que los ingenieros, arquitectos y diseñadores creen sistemas seguros y eficientes. Las fuerzas internas se generan dentro de un cuerpo debido a la interacción entre sus partículas. Estas fuerzas se pueden clasificar en fuerzas de tensión, compresión y corte. Estas fuerzas internas existen en pares colineales con igual magnitud pero direcciones opuestas. Se cancelan entre sí en todas las partes conectadas, manteniendo el equilibrio del cuerpo. El peso de un cuerpo es una fuerza externa representada por una única fuerza resultante que actúa a través del centro de gravedad del cuerpo. El centro de gravedad es el punto en el que un cuerpo se equilibra cuando no hay fuerza externa actuando sobre él. El centro de gravedad se encuentra en el centro geométrico para cuerpos simétricos o uniformes. Sin embargo, el centro de gravedad puede estar descentrado hacia el lado más pesado en cuerpos irregulares o no uniformes. La comprensión de las fuerzas internas y el centro de gravedad es crucial para analizar y mantener la estabilidad y el equilibrio de varias estructuras y objetos. Por ejemplo, en ingeniería civil, estos principios se utilizan para diseñar puentes, edificios y otras infraestructuras capaces de resistir fuerzas externas como el viento, los terremotos y las cargas de tráfico. En ingeniería mecánica, el conocimiento de las fuerzas internas y el centro de gravedad se aplica para diseñar máquinas, vehículos y otros sistemas mecánicos que pueden funcionar de manera segura y eficiente bajo diversas cargas y condiciones. En ingeniería aeroespacial, determinar con precisión el centro de gravedad de aeronaves y naves espaciales es vital para garantizar la estabilidad y el control durante el vuelo. Un cambio en el centro de gravedad puede tener consecuencias graves para el rendimiento y la seguridad de estos vehículos.

Fuerzas internas y centro de gravedad

Las fuerzas internas y el centro de gravedad son conceptos fundamentales en mecánica, que desempeñan un papel crucial en la comprensión del comportamiento y la estabilidad de ...

Education

Educación

JoVE Core

Mechanical Engineering

Ingeniería Mecánica

Unit 1

Unidad 1

Equilibrium of a Rigid Body

Equilibrio de un cuerpo rígido

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

forces inside a body and balance

Internal forces and the center of gravity help explain how objects stay in balance. These mechanics ideas matter for structures, machines, and vehicles that must remain stable under different loads and conditions.

Internal forces are created inside a body when its particles interact. They can appear as tension, compression, or shear forces. These forces act in collinear pairs with equal magnitude and opposite direction. Between connected parts, they cancel each other and help keep the body in equilibrium.

A body’s weight is an external force. It is shown as one resultant force acting through the center of gravity. The center of gravity is the point where a body balances when no external force acts on it. For symmetrical or uniform bodies, this point is at the geometric center. For irregular or non-uniform bodies, it may shift toward the heavier side.

These ideas are important in civil engineering, mechanical engineering, and aerospace engineering. Engineers use them to design bridges, buildings, machines, vehicles, aircraft, and spacecraft that can handle wind, earthquakes, traffic loads, and other forces. If the center of gravity changes, the stability and safety of an aircraft or spacecraft can be affected.

Forces Inside a Body and Balance

conditions of equilibrium

Rigid Body Force Balance in Equilibrium

Rigid body equilibrium depends on a balance of external forces and moments. A rigid body is in equilibrium when it has no translational motion and no rotational motion. This happens when the net force and the net couple acting on the body are both zero. Internal forces are not used when checking equilibrium. These forces act in equal and opposite pairs inside the body, so they cancel each other. Because of that, they do not affect the overall motion or change in motion of the rigid body. The...

support reactions

Types of Structural Supports

Types of structural supports control how a coplanar force system moves and reacts under load. A coplanar force system is a set of forces that all lie in the same plane. The supports create reactions at the point of contact. These reactions help keep a structure stable under external forces. Supports work by stopping translation with an equal and opposite force. They can also stop rotation by applying a couple moment in the opposite direction. In structural design, these reactions are important...

internal forces and center of gravity

Internal forces and the center of gravity help explain how objects stay in balance. These mechanics ideas matter for structures, machines, and vehicles that must remain stable under different loads and conditions. Internal forces are created inside a body when its particles interact. They can appear as tension, compression, or shear forces. These forces act in collinear pairs with equal magnitude and opposite direction. Between connected parts, they cancel each other and help keep the body in...

alternative sets of equilibrium equations

alternative-sets-of-equilibrium-equations

Equilibrium Conditions for a Supported Plate

Equilibrium conditions for a supported plate are used to describe when forces and moments balance. In this state, the plate has no net movement and no rotation. Engineers use these equations to study how structures behave under external loads. In many cases, the standard equilibrium equations are enough. But some systems need an alternative set of equations to match the geometry of the support points. A rectangular plate supported at points A, B, and C is one example. For this plate, the...

two force member

Two-Force Body Equilibrium

A two-force body is a rigid body acted on by only two external forces. In equilibrium, those two forces must have the same magnitude, the same line of action, and opposite directions. This balance is what keeps the body at rest. For a plate with forces F1 and F2 applied at points A and B, equilibrium means the sum of moments about any axis is zero. If moments are summed about point A, the moment from F2 must be zero. That means the line of action of F2 must pass through point A. The same idea...

three force member

Solving a Three-Force Member Example

A three-force member is a rigid body acted on by three forces at three points. The forces must have concurrent lines of action. If the forces are parallel, their lines of action stay parallel instead. A dumpster provides the example used here. It is connected to a pin support at point A and to a pin on a hydraulic cylinder at point B. The hydraulic cylinder acts as a two-force member in equilibrium. The dumpster weight acts through the center of gravity, and the support reaction acts at point...

equations of equilibrium in three dimensions

equations-of-equilibrium-in-three-dimensions

Checking Force Balance in 3D Structures

Checking force balance in 3D structures is a key step when a system is at rest. The vector and scalar equations of equilibrium are used to test whether a body is stable and will not collapse or fall apart. These equations give a clear way to study the forces acting on a body. The vector equations of equilibrium require the vector sum of all external forces on a body to equal zero. They also require the vector sum of the couple moments and the moments of all forces about a point to equal zero.

support reactions in three dimensions

3D Support Types for Stability and Motion

Support reactions in three dimensions keep structures stable and in equilibrium. They stop unwanted translation and rotation, so a design can handle external forces safely and work as intended. These reactions are important in many structures and systems. A ball and socket joint is one support that allows free rotation about any axis. It does not provide a moment that resists turning. At the same time, it restricts motion in space with three reaction forces along the three dimensions. A...

constraints and statical determinacy

Constraints in Structural Equilibrium

Constraints in structural engineering control how a body can move and help keep it in mechanical equilibrium. A constraint is a restriction on motion. When the right number of constraints is used, the system can stay balanced with the fewest supports needed. A system with the proper number of supports is called statically determinate. In that case, the unknown reaction forces can be found from equations of equilibrium. These systems are the easiest to analyze and design because the forces can...

key terms and concepts

Learn how internal forces and the center of gravity affect balance, stability, and equilibrium in structures, machines, and vehicles.

Forces Inside a Body and Balance | 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

Forces Inside a Body and Balance

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