Name: types of structural supports
Uploaded: 2023-09-22T11:49:22.000Z
Duration: 1 min 30 s
Channel: JoVE

力学では、同一平面上の力システムは、接触点とサポートの間でさまざまなタイプの反応を経験します。
サポートは、等しく反対の力を加えることにより、システムの並進運動を防ぎます。また、反対方向に数モーメントを適用することにより、システムの回転を防ぎます。
ローラーサポートにより、構造は一方向にのみ並進できます。ローラーサポートでの反応は、サポートに対して垂直に作用する単一の力になります。
ピンサポートはビームの回転のみを許可し、ビームの並進運動を制限します。これは、ピンの軸に垂直な平面に加えられた力に対する反応を生成します。この力は、その長方形の成分に分解できます。
固定支持体は、加えられた力に2つの反力とモーメントを提供することにより、構造が任意の方向に並進および回転するのを抑制します。力 Fx はサポートの軸に沿って水平方向に作用し、Fy はサポートに対して垂直に作用します。

<ol>
	<li>ヒベラー、RC(2016)。エンジニアリングメカニクス \u2012 静力学と力学。 ニュージャージー州ホーボーケン:ピアソンプレンティスホール。209-211ページ</li>
</ol>

支持力

Support Reactions

共面力とは、すべてが同じ平面内にあり、接触点と支持の間で異なる反応を受ける力の集合を指します。共面力に対する異なるタイプのサポートの影響を理解することは、外部荷重に耐える安全で信頼性のある構造を設計するために重要です。

支持の目的は、等しい逆向きの力を適用することによってシステムの平行移動を防止し、逆方向の力のカップルを適用することによってシステムの回転を防止することです。目的と適用によって、主に3つの主要なタイプの支持があります：ローラー支持、ピン支持、固定支持。

ローラー支持は、その表面に垂直な単一の反力を提供することによって、一方向の平行移動のみを許可します。このタイプのサポートは、温度変化によって膨張または収縮する橋など、移動を制限する必要がある場所で頻繁に使用されます。

ピン支持は、外力に対して垂直な平面で反力を提供します。これにより回転が許可されますが、平行移動は制限されるため、カンチレバーや長さに沿った一様な荷重条件を持つ構造物に有用です。

最後に、固定支持は、外力に対して2つの反力とモーメントを提供することにより、平行移動と回転の両方を防止します。このタイプの支持は、高い安定性の要件を持つ建物などでよく使用されます。

同一平面上の力システムとは、すべてが同じ平面にあり、接触点と接触点の間で異なる反応を受ける一連の力を指します...

Education

JoVE Core

Mechanical Engineering

機械工学

Unit 1

ユニット1

Equilibrium of a Rigid Body

剛体のつり合い

KEY TERMS AND CONCEPTS

主要用語と概念

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 for safe and reliable systems. They help structures resist loads without unwanted motion.

There are three main support types: roller support, pin support, and fixed support. A roller support allows translation in only one direction. It provides a single reaction force normal to its surface. This support is useful where movement must still happen in a controlled way, such as in bridges that expand or contract with temperature changes.

A pin support provides a reaction force in the plane perpendicular to its axis when force is applied. It permits rotation but restricts translational motion. This makes it useful for structures with cantilevers or with uniform loading conditions along their length. A fixed support prevents both translation and rotation. It provides two reaction forces and a moment, so it is often used in buildings where high stability is needed.

Types of Structural Supports

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 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

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...

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 roller, pin, and fixed supports react to coplanar forces, and how each one limits translation or rotation in structures.

Types of Structural Supports | JoVE K12

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mechanical engineering

Types of Structural Supports

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