Name: 3d support types for stability and motion
Uploaded: 2023-09-22T11:49:23.000Z
Duration: 1 min 27 s
Channel: JoVE

يتم استخدام مجموعة متنوعة من الدعامات في الهندسة الميكانيكية بناء على تطبيقها. تمنع تفاعلات الدعم هذه في نظام القوة ثلاثي الأبعاد النظام من الترجمة والتدوير.
ضع في اعتبارك ذراعا روبوتية ترفع الوزن. هنا ، المفصل A عبارة عن مفصل كروي ومقبس. الذراع حر في الدوران حول أي محور حيث لا توجد لحظة لتقييد الدوران في مفصل الكرة والمقبس. ومع ذلك ، فإنه يقيد الحركة الانتقالية بسبب قوى التفاعل الثلاث على طول الأبعاد الثلاثة.
بالتناوب ، المفصل B على الذراع هو دعامة واحدة ناعمة. يخلق هذا الدعم ثلاث قوى رد فعل واثنين من اللحظتين ويسمح بالحركة الدورانية على طول محور الدبوس.
قاعدة الذراع الروبوتية عبارة عن دعم ثابت ، ولها قوى رد فعل ولحظات على طول الاتجاهات الثلاثة.
نوع آخر من الدعم هو دعم المفصلات ، ويستخدم بشكل شائع في الباب. ثلاث قوى رد فعل عند الدعم تقيد الحركة الانتقالية للباب ، بينما تقيد لحظتان دوران الباب.

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	<li>هيبلر ، آر سي (2016). الميكانيكا الهندسية - الإحصاء والديناميكيات. هوبوكين ، نيو جيرسي: قاعة بيرسون برنتيس. ص 245-248</li>
	<li>بير ، إف بي ؛ جونستون ، إي آر ؛ مازوريك ، د. إف. كرومويل ، بي جيه وسيلف ، ب. (2019). ميكانيكا المتجهات للمهندسين - الإحصاء والديناميكيات. نيويورك: ماكجرو هيل. ص 208</li>
	<li>مريم ، جي إل. كريج ، إل جي وبولتون ، ج. (2020). الميكانيكا الهندسية - الإحصاء. هوبوكين ، نيو جيرسي: جون وايلي. ص 145</li>
</ol>

دعامات ردود الفعل في الأبعاد الثلاثة

Support Reactions in Three Dimensions

<div style="direction:rtl">تساعد دعامات ردود الفعل في تلاثة أبعاد على الحفاظ على استقرار وتوازن مختلف الهياكل والأنظمة. تمنع هذه التفاعلات تحويل النظام وتدوره، مما يضمن أن يتحمل التصميم القوى الخارجية وأن يقوم بوظيفته المقصودة بكفاءة وبأمان. يتم مناقشة بعض الدعامات التي يوفرها ردود الفعل في الأبعاد الثلاثة أدناه: واحد من الدعامات التي تسمح بالدوران الحر حول أي محور هو دعامات مفصل الكرة والمقبس. يكون الدوران الحر ممكنًا في هذا النوع من التصميم بسبب عدم وجود عزم يقيد الدوران في مفصل الكرة والقبس. ومع ذلك، يحد مفصل الكره من حركة الانزلاق بسبب ثلاث قوى ردود الفعل على الأبعاد الثلاثة. نوع آخر من الدعامات هي الدعامة المفصلية السلسة .تنشأ هذه الدعامة ثلاث قوى ردة فعل وزوجين من عزم الازدواج، مما يسمح بحركة دورانية على طول محور المفصل مع تقييد الحركة في الاتجاهات الأخرى. الدعم الثابت يؤمن قوى ردود الفعل وعزم على جميع الاتجاهات الثلاثة. يضمن هذا النوع من الدعم بقاء النظام بأكمله ثابتًا وآمنًا تحت الأحمال والظروف المختلفة، مما يمنع الحركة أو التشوه غير المرغوب فيه الذي يمكن أن يعرض وظائف النظام للخطر. دعامة المفصلة هو نوع آخر شائع من الدعم المستخدم في الهندسة الميكانيكية، ويستخدم في الأبواب والتطبيقات المماثلة الأخرى. مع دعم المفصلة، تقيد ثلاث قوى ردّة فعل الحركة التفاضلية للباب، في حين تقيد عزمان الدوران للباب. يتيح هذا النوع من الترتيب للباب الدوران حول محور واحد مع الحفاظ على الاستقرار والتحكم.</div>

تساعد تفاعلات الدعم في ثلاثة أبعاد في الحفاظ على استقرار وتوازن الهياكل والأنظمة المختلفة. هذه التفاعلات تمنع النظام ...

Education

JoVE Core

Mechanical Engineering

الهندسة الميكانيكية

Unit 1

الوحدة الأولى

Equilibrium of a Rigid Body

توازن الجسم الجاسئ

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

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 single smooth pin support works differently. It creates three reaction forces and two couple moments. This setup allows rotation along the axis of the pin while restricting movement in the other directions.

Fixed supports provide reaction forces and moments in all three directions. They help keep the system stable and secure under different loads and conditions. This also helps prevent unwanted movement or deformation that could affect function.

Hinge support is another common support used in mechanical engineering, especially in doors and similar applications. It produces three reaction forces that block translational motion of the door. Two moments restrict the door’s rotation, but it can still turn about one axis.

3D Support Types for Stability and Motion

3d-support-types-for-stability-and-motion

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

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

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 ball and socket joints, smooth pin supports, fixed supports, and hinge supports control movement and keep 3D structures stable under load.

3D Support Types for Stability and Motion | 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

3D Support Types for Stability and Motion

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