Name: beam loads and internal forces
Uploaded: 2025-05-22T09:06:03.000Z
Duration: 1 min 14 s
Channel: JoVE

빔에 다른 하중이 가해지면 내부 힘이 생성됩니다. 이러한 힘은 빔의 가상점을 고려하고 단면 방법을 사용하여 결정할 수 있습니다.
빔의 단면에 수직으로 작용하는 내력을 수직력 또는 축력이라고 하고, 단면에 접선으로 작용하는 힘을 전단력이라고 합니다.
이러한 힘은 각 세그먼트에서 반대 방향으로 작용하며 평형 방정식을 적용하여 결정할 수 있습니다.
다양한 하중을 가진 캔틸레버 빔 OB를 고려하십시오. 빔의 중심에서 작용하는 법선과 전단력을 결정합니다.
이러한 힘은 단면 방법을 사용하고 빔의 세그먼트 AB에 가해지는 힘을 분석하여 결정할 수 있습니다.
유사한 삼각형의 개념을 사용하여 중심의 힘을 결정할 수 있습니다.
자유물체 다이어그램을 그리고 평형 방정식을 사용하여 법선력과 전단력을 결정할 수 있습니다.

<ol>
	<li>히벨러, R.C. (2016). Engineering Mechanics \u2012 정역학 및 동역학. 뉴저지 호보켄: 피어슨 프렌티스 홀. 343-344쪽.</li>
</ol>

수직력과 전단력

보에 무게, 압력 또는 기타 외부 힘과 같은 다양한 하중이 가해지면 보 내에 내부 힘이 발생합니다. 이러한 힘은 구조물의 전반적인 안정성과 강도에 상당한 영향을 미칠 수 있습니다. 엔지니어들은 이러한 내부 힘의 크기와 방향을 분석하고 결정하기 위해 다양한 방법을 사용합니다. 보의 내부 힘을 결정하기 위해 사용되는 한 가지 일반적인 기술은 단면(section)의 방법입니다. 이 방법은 보 위의 가상의 지점이나 섹션을 고려하고 그 특정 지점에 작용하는 힘을 분석하는 것을 포함합니다.
수직력은 보의 단면에 수직으로 작용하는 내부력으로 축력이라고도 합니다. 이 힘은 보에 가해지는 하중의 특성에 따라 압축력일 수도 인장력일 수도 있습니다. 한편 전단력은 보의 단면에 접선으로 작용하는 내부력입니다. 전단력은 보의 각 세그먼트에서 반대 방향으로 작용합니다. 수직력과 전단력은 고려 중인 보에 평형방정식을 적용하여 결정할 수 있습니다. 
보 및 기타 구조 요소의 안정성, 강도 및 전체 성능을 결정하는 데 이러한 힘이 중요한 역할을 하기 때문에 정상 및 전단력을 이해하는 것은 구조 공학에서 매우 중요합니다. 단면 및 평형 방정식 방법을 사용하여 엔지니어는 보 내의 내부 힘을 정확하게 결정하고 사용 수명 동안 직면하는 하중과 응력을 견딜 수 있는 구조를 설계할 수 있습니다.

빔이 무게, 압력 또는 기타 외부 힘과 같은 다른 하중을 받으면 빔 내에서 내부 힘이 생성됩니다. 이러한...

Education

교육

JoVE Core

Mechanical Engineering

기계공학

Unit 1

제1단원

Internal Forces

내력

KEY TERMS AND CONCEPTS

주요 용어 및 개념

Normal and Shear Force

beam loads and internal forces

Beam loads create internal forces inside a structure. Weight, pressure, and other external forces can all act on a beam. These internal forces affect the beam’s stability and strength.

Engineers study these forces to find their size and direction. A common approach is the method of sections. In this method, an imaginary cut is made at a chosen point on the beam, and the forces at that section are analyzed.

One internal force is the normal force, also called the axial force. It acts perpendicular to the beam’s cross-section. Depending on the load, this force can be compressive or tensile.

The other main internal force is the shear force. It acts tangentially, or along the cross-section. Shear forces act in opposite directions on each segment of the beam.

Normal and shear forces can be found by using equilibrium equations on the beam. This analysis is important in structural engineering. It helps engineers judge the stability, strength, and performance of beams and other structural elements.

Beam Loads and Internal Forces

sign convention

Beam Forces: Tension, Shear, and Bending

Beam analysis depends on the internal forces and moments inside a structure. These include normal force, shear force, and bending moment. Engineers use the method of sections to cut the beam and find these values. A sign convention helps show whether each result is positive or negative. Normal force acts perpendicular to the beam’s cross-section. It can pull the material in tension or push it in compression. Tension is taken as positive, while compression is taken as negative. This makes it...

normal and shear force

Beam loads create internal forces inside a structure. Weight, pressure, and other external forces can all act on a beam. These internal forces affect the beam’s stability and strength. Engineers study these forces to find their size and direction. A common approach is the method of sections. In this method, an imaginary cut is made at a chosen point on the beam, and the forces at that section are analyzed. One internal force is the normal force, also called the axial force. It acts...

bending and torsional moments

Forces That Bend and Twist Materials

Bending and torsional moments describe how materials respond to force. These ideas are important in structural engineering because they help explain how beams, rulers, and screws change shape under load. A moment depends on both the size of the force and the distance from the point of interest to the force’s line of action. A bending moment forms when an external force makes a structural element bend. If the element bends upward, the top side is in compression and the bottom side is in tension.

internal loadings in structural members: problem solving

internal-loadings-in-structural-members-problem-solving

Beam Internal Force Analysis at Point A

Beam internal force analysis shows how normal force, shear force, and bending moment act inside a structural member. These internal loadings help engineers check whether a beam can support the external forces applied to it. The example uses a beam OC that weighs 5 kN and is inclined at 53.13° with the horizontal. The beam is supported at both ends. The goal is to find the internal loadings at point A. The first step is to find the reaction force at point C. This is done by taking the moment...

beams

Beam Types and Support Conditions

Beams are key parts of structural engineering and construction. They support loads that act at different points along their length. Engineers use beam shape and support conditions to understand how a beam will perform. Beams can be classified by geometry. Straight beams are the most common and have a constant cross-section along their length. Tapered beams change in cross-section from one end to the other, while curved beams have a curved shape. Beam cross-section also matters. Common shapes...

shear diagram

Beam Shear Force Diagram

Beam shear force diagrams show how shear changes along the length of a supported beam. In beam mechanics, they help students track the internal shear force caused by perpendicular loads. The beam AB in this example is supported at both ends, so the first step is to draw a free-body diagram that shows the external forces and internal reactions. The reaction forces at supports A and B are found with equilibrium equations for force and moment. For the beam shown, the vertical reaction at A is 24...

bending moment diagram

Beam Load Analysis with Moment Diagrams

Beam load analysis uses a bending moment diagram to show how bending changes along the length of a beam. This diagram helps engineers and designers check whether a structure can handle applied forces. It is also useful for parts such as shelving arms, which must resist forces and moments from a load. To build the diagram, start by finding the reactive forces and any couple moments on the beam. In some cases, especially when a beam is inclined, these forces must be resolved into components that...

relation between the distributed load and shear

relation-between-the-distributed-load-and-shear

Shear Change Under Distributed Loading

Shear force changes along a beam under a distributed load. In structural analysis, this relationship helps explain how beams respond to loading conditions that also include concentrated loads and a couple moment. To study the link, consider a small beam section that has no concentrated load or couple moment on it. Draw a free-body diagram for that elemental section. It includes the distributed load along the beam, the shear force V(x) on the right-hand side of the cut, and a small added shear...

relation between the shear and bending moment

relation-between-the-shear-and-bending-moment

Shear and Moment Diagrams in Beam Loads

Shear and moment diagrams help show how a beam responds to loads. A beam can carry a distributed load, concentrated loads, and a couple moment. These loads create internal shear forces and bending moments. The beam is examined by isolating a small elemental section and drawing a free-body diagram. For that section to stay in equilibrium, the moment on the right side must be slightly larger than the moment on the left side. The distributed load also has a resultant force that acts at a...

shear and bending moment diagram: problem solving

shear-and-bending-moment-diagram-problem-solving

Beam Load Analysis with Shear Diagrams

Beam load analysis uses shear and bending moment diagrams to track the internal forces in a beam. These diagrams are important when a beam carries concentrated loads and a distributed load. They help show how the beam responds so structures can be designed safely and efficiently. The first step is to draw a free-body diagram of the whole beam. A free-body diagram shows the concentrated loads, the distributed load, and the reaction forces at the supports. Use the equilibrium equations, where...

cable subjected to concentrated loads

Finding Tension in a Loaded Cable

Flexible cables can carry vertical point loads between two fixed supports. The cable is treated as flexible, inextensible, and nearly weightless. Under these conditions, it changes shape to form straight-line segments, and each segment carries a constant tensile force. To analyze the cable, a free-body diagram is drawn for the whole cable. This helps identify the reaction forces at the supports. In many cases, the number of unknown reaction components is greater than the available equilibrium...

cable subjected to a distributed load

Finding Cable Shape Under Distributed Load

Cable shape under a distributed load is found by analyzing the forces along a small piece of the cable. This method is important in suspension bridge design because the main cables must carry changing loads safely. The load causes the tensile force in the cable to change, and it also creates cable deformation. The analysis starts with a free-body diagram of a short cable segment. The diagram shows the distributed load and the change in tensile force across that segment. Equilibrium equations...

cable subjected to its own weight

Cable Sag Under Its Own Weight

Overhead power transmission cables sag under their own weight, and that shape affects how they carry electricity across long distances. To study this behavior, the cable is analyzed with a generalized loading function. This function treats the load along the cable's arc length instead of its projected length, which gives a more accurate picture of the cable's response. The analysis then focuses on a small cable segment. A free-body diagram is drawn to show the forces acting on that segment.

cable: problem solving

Cable Tension Under Uniform Loading

Cable tension under uniform loading is found by analyzing a cable fixed between two supports. The problem starts with the support conditions and the load on the cable. From there, the cable’s shape must be described with an equation that matches the curve formed by the load. The next step is to integrate the shape equation to get the cable’s shape function. This makes it possible to solve for constants in the equation. The boundary condition at the origin gives one constant. The slope, which...

key terms and concepts

Learn how beam loads create internal normal and shear forces, and how engineers use the method of sections and equilibrium equations to analyze them.

Beam Loads and Internal Forces | 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

Beam Loads and Internal Forces

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