Name: normal stress in axial loading
Uploaded: 2024-03-07T13:22:32.000Z
Duration: 1 min 19 s
Channel: JoVE

Considere una varilla sometida a una fuerza axial; como resultado, se desarrolla una fuerza resistiva a través del área de la sección transversal, que se denomina tensión. La unidad de tensión del SI es Newton por metro cuadrado.
Ahora, considere un miembro de celosía de puente sometido a una fuerza axial. Desarrolla fuerzas internas y tensiones normales al plano de la sección transversal, llamadas tensiones normales.
La tensión normal resultante representa una tensión media sobre la sección transversal, en lugar de en un punto específico.
De acuerdo con las condiciones de equilibrio, las fuerzas internas son iguales a la fuerza aplicada, lo que implica que la distribución de la tensión es uniforme, excepto cerca del punto de aplicación.
Sin embargo, esta distribución uniforme solo es posible si la línea de acción de las cargas pasa a través del centroide de la sección, lo que se denomina carga céntrica.
Cuando la carga axial se aplica excéntricamente, la distribución de fuerzas y tensiones no puede ser uniforme o simétrica debido al momento adicional creado.
Por lo tanto, la distribución de tensiones real en un miembro cargado axialmente es estáticamente indeterminada y depende del modo específico de aplicación de la carga.

tensión normal

La tensión normal es un tipo de tensión que ocurre cuando las fuerzas actúan perpendiculares o normales al área de la sección transversal de un material. Esta tensión surge a menudo en estructuras cuando se someten a cargas axiales, que es la aplicación de fuerza a lo largo del eje de un objeto. Un ejemplo práctico de esto se puede encontrar en las vigas de puente.


Cuando una varilla está bajo carga axial, las fuerzas internas y el esfuerzo correspondiente son normales al plano de la sección, por lo que se denomina esfuerzo normal. Es importante tener en cuenta que la tensión representa el valor de tensión promedio en la sección transversal, no en un punto específico. La tensión promedio se calcula dividiendo la magnitud de las fuerzas internas resultantes distribuidas sobre la sección transversal por el área de la sección transversal.


<img alt="Equation 1" src="/files/ftp_upload/15579/15579_Equation_1.svg" style="text-align: center; height: 42px;">

Sin embargo, la tensión en un punto dado puede diferir de la tensión promedio, ya que varía a lo largo de la sección. Especialmente en varillas delgadas sometidas a cargas axiales, la variación puede ser significativa cerca de los puntos de aplicación de la carga.

Las condiciones de equilibrio sugieren una distribución uniforme de la tensión en miembros cargados axialmente, excepto cerca de los puntos de aplicación de la carga, suponiendo una carga céntrica. Sin embargo, la carga excéntrica crea tensiones no uniformes debido a momentos adicionales, lo que indica una distribución de tensiones estáticamente indeterminada.

Tensión normal

Considere una varilla sometida a una fuerza axial; Como resultado, se desarrolla una fuerza resistiva a través del área de la sección transversal, que se denomina tensión. El SI ...

Education

Educación

JoVE Core

Mechanical Engineering

Ingeniería Mecánica

Unit 1

Unidad 1

Concept of Stress

Concepto de estrés

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Normal Stress

normal stress in axial loading

Normal stress acts perpendicular to a material’s cross-sectional area. It appears when a force is applied along the axis of an object, which is called axial loading. Bridge truss members are a practical example of this kind of loading.

When a rod carries axial load, internal forces develop across the section. Because these forces act normal to the plane of the section, the stress is called normal stress. Stress here means the average stress over the whole cross-section, not the value at one exact point.

The average stress is found by dividing the resultant internal force by the cross-sectional area. The stress at a specific point can be different from that average, since it may vary across the section. In slender rods under axial load, that variation can be large near the points where the load is applied.

For a centric load, equilibrium suggests a uniform stress distribution in an axially loaded member, except near the load application points. Eccentric loading changes that pattern. It creates non-uniform stress because extra moments act on the member, so the stress distribution becomes statically indeterminate.

Normal Stress in Axial Loading

normal stress

Normal stress acts perpendicular to a material’s cross-sectional area. It appears when a force is applied along the axis of an object, which is called axial loading. Bridge truss members are a practical example of this kind of loading. When a rod carries axial load, internal forces develop across the section. Because these forces act normal to the plane of the section, the stress is called normal stress. Stress here means the average stress over the whole cross-section, not the value at one...

shearing stress

Shear Forces in Bolts and Rivets

Shearing stress is caused by transverse forces acting on an object. These forces create internal forces in the plane where the external forces are applied. The total internal force in that section is called the shear. Average shearing stress is found by dividing the shear by the cross-sectional area. This value is only an average, because shear stress is not spread evenly across the section. It can be zero at the surface and much higher than the average in other areas. Bolts, pins, and rivets...

bearing stress

Bolt-to-Plate Contact Pressure

Bearing stress is the contact pressure between two separate bodies. A common example is a bolt pushed through a plate. The bolt applies a force to the plate, and the plate pushes back with an equal and opposite force. That force is not a single point load. It is made up of many smaller forces spread across the contact surface between the bolt and the plate. Because these microforces are complex, engineers use an average value called bearing stress. Bearing stress is found by dividing the...

applications of stress

Boom and Rod Stress Analysis

Boom and rod stress analysis shows how a pinned support structure carries a load. The boom and the rod are connected by a pin and held in place by brackets and pins. The structure is then separated from its supports so the forces can be studied clearly. A free-body diagram is drawn to identify every force on the boom, the rod, and the load. The reaction forces on both members are found using equilibrium equations. At point P, the reaction causes compression in the boom. At point R, the...

stress on an oblique plane

Axial Load Stress on Inclined Sections

Axial loading creates stress in a material along its central axis. This kind of load can cause compression or elongation, and it produces normal stress. Normal stress acts perpendicular to the material area and can be either tensile or compressive. When the section is not perpendicular to the load, it becomes an oblique plane. On this inclined plane, the stress state includes both normal stress and shearing stress. Shearing stress acts parallel to the area and changes shape without changing...

stress: general loading conditions

Stress Components on a Loaded Body

Stress components on a loaded body can be found by cutting the body through a point with a plane parallel to the xy plane. That section carries the original loads, along with normal forces and shearing forces. The result is a simple way to describe how a structure responds under combined loading. The shearing force in the section can point in different directions within the plane. It is split into two parts that run parallel to the x and y axes. Each part is divided by the area, and as that...

components of stress

Stress Components on a Cube at a Point

Stress components on a small cube help describe how a body behaves under multiple loading. The cube is centered at point O and has stress acting on all six faces, whether the faces are visible or hidden. Normal stress components σx, σy, and σz act perpendicular to the x, y, and z axes. Shearing stress components also act on the cube faces. The visible faces carry shear stresses such as τxy and τxz. The hidden faces carry equal and opposite stresses. This balance keeps the cube in equilibrium.

design consideration

Safety Factors in Structural Design

Safety factors in structural design help engineers choose a material and loading limit that can be used safely. The process begins with a material’s ultimate strength. This value comes from tests that increase force until the material reaches its breaking point or limit. The ultimate load is then divided by the original cross-sectional area to find the ultimate normal stress, or strength. Ultimate shearing stress is another key value used in design. These limits show how much stress a material...

key terms and concepts

Learn how normal stress forms in axially loaded members, how to calculate average stress, and why stress can vary across a cross-section.

Normal Stress in Axial Loading | 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

Normal Stress in Axial Loading

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