Name: bolt-to-plate contact pressure
Uploaded: 2025-05-22T09:06:17.000Z
Duration: 1 min 22 s
Channel: JoVE

別の物体と相互作用する際に生じる接触圧力によって材料に加えられる応力は、ベアリング応力と呼ばれます。
ボルトで接続された2つのプレートを考えてみましょう。ボルトは、プレートの1つに内部力を加えます。この内部力は、プレートがボルトに及ぼす力と同等ですが、反対です。
ここで、内力は単数形ではなく、半円柱の内面全体に分散された多数の小さな力の結果です。
小さな力とそれに対応する応力が複雑であるため、単純化のためにベアリング応力と呼ばれる平均公称応力がよく使用されます。
ベアリング応力は、内力をプレート断面上のボルトの投影を表す長方形の面積で割ることによって計算されます。この領域は、プレートの厚さとボルトの直径の積です。
ベアリング応力の概念は、安全で効率的な構造設計を確保する上で極めて重要であり、したがって構造の寿命を延ばします。

荷重に耐える

Bearing Stress

軸受荷重とは、2つの別個の物体間の接触圧力を指します。 これを視覚化するには、ボルトがプレートに突き刺さったことを想像してください。 ボルトはプレートに力を加え、その力は等しいが反対の力をボルトに戻します。 この力は単なる単一の実体ではなく、ボルトとプレートの間の接触面全体に分散される多数の小さな力の集合体です。

これらの微小力は複雑であるため、技術者は単純化のためにベアリング荷重として知られる平均値を使用することがよくあります。 ベアリング応力は、ボルトに加えられる荷重をプレート上のボルトの投影面積で割ることによって求められます。

<img alt="Equation1" src="/files/ftp_upload/15581/15581_Equation_1.svg" style="height: 46px;">

軸受荷重を理解することは、構造工学の重要な部分です。 これにより、エンジニアは構造内でさまざまな力がどのように相互作用するかを批判的に理解できるようになります。 この知識は、設計の安全性と効率性を確保するのに役立つため、構造物を設計する際に非常に重要です。

ベアリング応力を正確に計算することで、エンジニアは過剰な力による潜在的な故障を防ぎ、構造の寿命を延ばすことができます。 結論として、耐力応力は構造工学において極めて重要な概念です。 構造物の耐久性と安全性を決定する重要な要素です。

別の物体と相互作用する際に生じる接触圧力によって材料に加えられる応力は、ベアリング応力と呼ばれます。
2つのプレートを考えてみましょう...

Education

JoVE Core

Mechanical Engineering

機械工学

Unit 1

ユニット1

Concept of Stress

ストレスの概念

KEY TERMS AND CONCEPTS

主要用語と概念

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 bolt’s applied load by the projected area of the bolt on the plate. This calculation helps engineers understand how forces act inside a structure. It is an important part of structural engineering because it supports safe and efficient design.

By calculating bearing stress correctly, engineers can reduce the risk of failure from too much force. It also helps them improve the lifespan of a structure. Bearing stress is a key factor in judging durability and safety.

Bolt-to-Plate Contact Pressure

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...

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

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 bearing stress describes contact pressure between a bolt and a plate, how it is calculated, and why it matters in structural engineering.

Bolt-to-Plate Contact Pressure | JoVE K12

JoVE Core 機械工学は、平衡、力、トラス解析、構造力学などの重要なトピックをカバーする簡潔でわかりやすいアニメーション ビデオを提供します。実際のアプリケーションを探索し、科学者主導の実験を通じてこれらのコンセプトが実際に動作しているのを目撃してください。

mechanical engineering

Bolt-to-Plate Contact Pressure

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