Name: eccentric load stresses in structural columns
Uploaded: 2024-05-23T13:00:08.000Z
Duration: 1 min 21 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Physics

PHYS.2

PHYS.2.D

design-of-columns-under-an-eccentric-load

Design of Columns under an Eccentric Load

Simetri düzleminde eksantrik eksenel yük ile yüklenmiş bir kolon için, eksantrik yükten kaynaklanan normal gerilmeler, eşdeğer bir merkezli yük ve eğilmeden kaynaklanan gerilmeler olarak yazılabilir.
Eksantrik yüklemeli kolonlar tasarlanırken, kolonda oluşan maksimum gerilme, izin verilen maksimum gerilmeyi aşmamalıdır. Bu koşul iki farklı yaklaşım kullanılarak karşılanabilir.
İzin verilen gerilim yöntemi, eksantrik olarak yüklenmiş kolon için izin verilen gerilimin, merkezi olarak yüklenmiş kolon için maksimum gerilimle aynı olduğunu varsayar. Kolon için izin verilen gerilim, narinlik oranının bir fonksiyonu olarak ifade edilebilir.
Merkezli yükleme için izin verilen gerilim, eğilme momenti nedeniyle olandan daha küçüktür. Bu, izin verilen stres yönteminin aşırı muhafazakar olmasına neden olur. 
Öte yandan, etkileşim yöntemi, merkezli yükleme ve eğilme nedeniyle izin verilen gerilimi dikkate alır.
Birkaç moment olmadığında merkezi yükleme altında maksimum gerilim için bir denklem sağlar. Benzer şekilde, yükleme olmadığında saf eğilmeden kaynaklanan maksimum gerilimi tanımlar.

eksantrik yük altındaki kolonların tasarımı

Kolonların eksantrik yüklere dayanacak şekilde tasarlanması yapı mühendisliğinin kritik bir yönüdür ve yapıların merkez dışı yükleri arıza olmadan destekleyebilmesini sağlar. Bu tasarım süreci, bir kolonun gerilim dağılımını ve genel stabilitesini önemli ölçüde etkileyebilecek eksantrik yüklemenin getirdiği ek normal gerilimleri hesaba katmalıdır. Bir kolona uygulanan eksantrik yük, eşdeğer merkezsel yük ve ek eğilme gerilimlerinden kaynaklanan gerilimlerin bir kombinasyonu olarak kavramsallaştırılabilecek normal gerilimlere neden olur. Bu, yapısal arızayı önlemek için dikkatlice analiz edilmesi gereken, düzgün olmayan bir gerilim dağılımına yol açar. Eksantrik yükler altındaki kolonların tasarımında iki temel yöntem kullanılır: izin verilen gerilme yöntemi ve etkileşim yöntemi.

İzin verilen gerilim yöntemi, eksantrik olarak yüklenen bir kolon için izin verilen gerilimin, merkezi olarak yüklenen bir kolon için izin verilen maksimum gerilime eşit olduğu basit bir yaklaşımdır. Bu yöntem, izin verilen gerilimi kolonun yük altında bükülme eğiliminin bir ölçüsü olan narinlik oranının bir fonksiyonu olarak ele alarak tasarım sürecini basitleştirir. Ancak bu yöntem, merkezli yükleme için izin verilen gerilimin, bükülmeden kaynaklanan ek gerilimleri kapsadığını varsayar ve bu da malzemenin tüm potansiyelini kullanamayan muhafazakar tasarımlara yol açar. Bu yaklaşımın doğasında olan muhafazakarlık güvenliği sağlar ancak gereğinden daha büyük ve daha pahalı sütunlarla sonuçlanabilir.

Etkileşim yöntemi, hem merkezi yükleme nedeniyle izin verilen gerilimleri hem de bükülme momentlerinden kaynaklanan gerilimleri dikkate alarak daha incelikli bir yaklaşım sunar. Bu yöntem, kolonun birkaç moment olmadan dayanabileceği maksimum gerilimi (saf merkezli yükleme) ve saf bükülmeden kaynaklanan maksimum gerilimi (eksenel yük olmadan) hesaplamak için bir çerçeve sağlar. Bu koşulları eş zamanlı olarak hesaba katan etkileşim yöntemi, eksantrik olarak yüklenen kolonlarda izin verilen gerilimlerin daha doğru ve daha az konservatif bir tahminine olanak tanır.

Uygulamada etkileşim yöntemi, güvenliği malzeme verimliliği ile dengeleme yeteneği nedeniyle sıklıkla tercih edilir. Hem eksenel yükleri hem de bükülme momentlerini dikkate alarak kolondaki gerilim dağılımının ayrıntılı bir analizini gerektirir.

Eksantrik Yük Altındaki Kolonların Tasarımı

Simetri düzleminde eksantrik bir eksenel yük ile yüklenmiş bir kolon için, eksantrik yükten kaynaklanan normal gerilmeler, bir ...

Education

JoVE Core

Mechanical Engineering

Makine Mühendisliği

Unit 1

Ünite 1

Columns

Sütunlar

KEY TERMS AND CONCEPTS

TEMEL TERİMLER VE KAVRAMLAR

eccentric load stresses in structural columns

Structural columns under eccentric load must be designed for both axial force and bending stress. An eccentric load is an off-center load, and it creates a non-uniform stress pattern across the column. Engineers must analyze this stress distribution carefully to reduce the risk of failure.

The stress in an eccentrically loaded column can be treated as the sum of two parts. One part comes from an equivalent centric load, which is a load applied through the center of the column. The other part comes from bending stresses caused by the load being off-center.

Two common design approaches are used for these columns. The allowable stress method sets the allowable stress for an eccentrically loaded column equal to the maximum stress allowed for a centrally loaded column. This method uses the column slenderness ratio, which describes how likely a column is to buckle.

The allowable stress method is simple, but it is also conservative. It assumes the centric-load allowable stress already covers the extra bending stress from eccentric loading. As a result, the column may be larger and more expensive than needed, even though the design is safe.

The interaction method gives a more detailed design check. It considers both the allowable stress from centric loading and the stress from bending moment at the same time. It compares the case of pure centric loading, with no couple moment, and the case of pure bending, with no axial load.

Because it includes both effects, the interaction method can estimate allowable stress more accurately. It is often preferred when engineers want a better balance between safety and material use. The method requires careful stress analysis of the column under both axial load and bending moment.

Eccentric Load Stresses in Structural Columns

eccentric-load-stresses-in-structural-columns

stability of structures

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euler&#39;s formula for pin-ended columns

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euler&#39;s formula to columns with other end conditions

euler-s-formula-to-columns-with-other-end-conditions

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euler&#39;s formula to columns: problem solving

euler-s-formula-to-columns-problem-solving

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eccentric loading

Column Bending Under Off-Center Load

Eccentric loading shows how a column bends when a force is applied off-center. In structural engineering, this matters because the load no longer acts along the centroidal axis, so the column sees both direct compression and bending stress. The off-center force can be treated as two parts. One part is a centric load F that acts along the column’s axis. The other part is a couple moment created by the eccentricity, or distance, between the load and the centroidal axis. To study the column...

design of columns under a centric load

Column Buckling and Load Design Basics

Column design under a centric load is a key part of structural engineering. It helps engineers keep buildings and other structures stable and safe. The main tools used here are Euler’s formula and Secant’s formula. Euler’s formula is used when a column is assumed to be perfect, straight, and uniform. It also applies when the material stays within its elastic limit. The critical load from Euler’s formula depends on the material’s modulus of elasticity and the column’s shape. This formula works...

design of columns under an eccentric load

Structural columns under eccentric load must be designed for both axial force and bending stress. An eccentric load is an off-center load, and it creates a non-uniform stress pattern across the column. Engineers must analyze this stress distribution carefully to reduce the risk of failure. The stress in an eccentrically loaded column can be treated as the sum of two parts. One part comes from an equivalent centric load, which is a load applied through the center of the column. The other part...

key terms and concepts

Learn how eccentric loads create combined axial and bending stresses in columns, and compare the allowable stress and interaction methods used in design.

Eccentric Load Stresses in Structural Columns | JoVE K12

JoVE Core Makine Mühendisliği, denge, kuvvetler, kafes kiriş analizi ve yapısal mekanik gibi temel konuları kapsayan kısa, anlaşılması kolay animasyonlu videolar sunar. Gerçek dünyadaki uygulamalarını keşfedin ve bilim insanlarının önderlik ettiği deneylerle bu kavramların uygulanmasına tanık olun.

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Eccentric Load Stresses in Structural Columns

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