Mechanical Engineering

Elastic Axial Deformation

Calculate extension or shortening of a uniform elastic bar.

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Calculate signed axial deformation or choose another supported quantity.

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Use decimals or scientific notation, such as 1.2e3. Calculations update as you type.

Signed axial deformation

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Enter the known values to see the result.

Use small strains and a homogeneous, linearly elastic material. Loads are static or slowly applied; remain below the proportional limit. Force, area, and modulus are constant along the bar; otherwise integrate F/(AE) along its length.

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Source & review

Difficulty

Intermediate

Read time

5 min

Prerequisites

Basic algebra, mechanics, and consistent SI units

Review statusNeeds review

Source

Donney Fan — MECH 360 — Mechanics of Materials

Reference equation: Axial Load — Elastic deformation under axial loading. FormuLab wrote new explanations, assumptions, applications, and numerical examples.

Definition

Understanding the core concept

An axial member stretches more when it is longer or more heavily loaded. A larger area or elastic modulus makes it stiffer, reducing the displacement.

Variables & Units

Understanding each component
SymbolMeaningUnits
Signed axial deformation
Signed axial force
Bar length
Cross-sectional area
Young’s modulus

Real-World Applications

Where this formula is used in practice

Tie-rod extension

Estimate extension under a known tensile load.

Axial stiffness

Compare materials and member dimensions.

Worked Example

Step-by-step calculation with real numbers

Problem

A 2 m steel bar with area 0.0004 m² and modulus 200 GPa carries 20,000 N in tension. Find its extension.

Given

Solution

1
2

Final Answer

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