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

축 방향 힘을 받는 막대를 생각해 보십시오. 그 결과, 저항력이 단면적을 가로질러 발생하며, 이를 응력이라고 합니다. 응력의 SI 단위는 제곱미터당 뉴턴입니다.
이제 축 방향 힘을 받는 교량 트러스 부재를 생각해 보십시오. 그것은 수직 응력이라고 하는 단면 평면에 수직인 내부 힘과 응력을 발생시킵니다.
결과 수직 응력은 특정 지점이 아닌 단면에 대한 평균 응력을 나타냅니다.
평형 조건에 따라 내부 힘은 적용된 힘과 같으며, 이는 적용 지점 근처를 제외하고는 응력 분포가 균일하다는 것을 의미합니다.
그러나 이러한 균일한 분포는 하중의 작용선이 단면의 중심을 통과하는 경우(중심 하중이라고 함)에서만 가능합니다.
축 하중이 편심으로 가해지면 생성된 추가 모멘트로 인해 힘과 응력의 분포가 균일하거나 대칭이 될 수 없습니다.
따라서 축 방향으로 하중을 받은 부재의 실제 응력 분포는 정적으로 불확정적이며 하중 적용의 특정 모드에 따라 달라집니다.

수직 응력

수직 응력은 힘이 재료의 단면적에 수직 또는 수직으로 작용할 때 발생하는 응력 유형입니다. 이 응력은 물체의 축을 따라 힘이 가해지는 축 하중을 받을 때 구조에서 종종 발생합니다. 이에 대한 실제적인 예는 교량 트러스 부재에서 찾을 수 있습니다.

로드가 축방향 하중을 받을 때 내부 힘과 해당 응력은 단면 평면에 수직이므로 이를 수직 응력이라고 합니다. 응력은 특정 지점이 아닌 단면에 대한 평균 응력 값을 나타낸다는 점에 유의하는 것이 중요합니다. 평균 응력은 단면에 걸쳐 분포된 결과 내부 힘의 크기를 단면 면적으로 나누어 계산됩니다.

<img alt="Equation1" src="/files/ftp_upload/15579/15579_Equation_1.svg" style="height: 42px;">

그러나 특정 지점의 응력은 단면에 따라 다르기 때문에 평균 응력과 다를 수 있습니다. 특히 축 하중을 받는 가는 로드의 경우 하중 적용 지점 근처에서 변화가 클 수 있습니다.

평형 조건은 중심 하중을 가정하여 하중 적용 지점 근처를 제외하고 축 하중 부재의 균일한 응력 분포를 제안합니다. 그러나 편심 하중은 추가 모멘트로 인해 불균일한 응력을 생성하여 정적으로 불확정한 응력 분포를 나타냅니다.

축 방향 힘을 받는 막대를 고려하십시오. 결과적으로, 저항력은 응력이라고 하는 단면적을 가로질러 발생합니다. SI ...

Education

교육

JoVE Core

Mechanical Engineering

기계공학

Unit 1

제1단원

Concept of Stress

스트레스의 개념

KEY TERMS AND CONCEPTS

주요 용어 및 개념

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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