Home   Tell-A-Friend    Discussion Board   Contact Us

civil engineer

Treasure of Civil Engineering Resources
Course materials, Books, Computer software, Quiz,  Conferences, Journals, Research theses, Jobs, Products, Services etc.
Moment of Inertia  

Moment of Inertia or second moment of area is a geometrical property of a section of structural member which is required to calculate its resistance to bending and buckling. Mathematically, the moment of inertia of a section can be defined as

  Moment of Inertia about x-x axis

   Moment of Inertia about y-y axis

 Moment of Inertia of some standard areas can be found below.

1. Rectangular section;

(a)  Ixx = (bd3)/12

(b) Iyy = (db3)/12

where b= width of the section, and d= depth of section.

The axes x-x and y-y are passing through the centroid and x-x axis is parallel to the width of section and y-y parallel to the depth.

Featured Links

Deflection Calculator

Easy to use calculator for different loads on beams

Problem SolverNew

A collection of illustrated solved examples for civil engineers.

RC Beam CalculatorNew

Calculate the strength of reinforced concrete beams

Reinforced concreteNew

Analysis and design of reinforced concrete structures

Bending Moment calculatorNew

Calculate Bending moments for simply supported beams

CE QUIZNew

A collection of quiz in different areas of civil engineering

2. Circular Section

  Ixx = Iyy = (πD4)/64,

where D is the diameter of the section and x-x and y-y axes are passing through the centroid.

We can use parallel axes theorem to find the moment of inertia about an axis parallel to x-x or y-y,

For example if p-q is an axis parallel to x-x and it is at a distance of 'h' from x-x axis. Then the moment of inertia  Ipq  about p-q axis can be determined as given below;

 Ipq = Ixx + Ah2

where A= the area of the section

Moment of inertia of hollow sections can also be determined by subtracting the moment of inertia of the removed area from the moment of inertia of original area.

Polar Moment of inertia is required in case of torsion of structural member.  Polar Moment of Inertia is defined as the Moment of inertia bout an axis perpendicular to the plane of the section and can be calculated by applying perpendicular axes theorem which says that

 Ixx + Iyy = Izz

Use our Moment of Inertia calculator to determine centroid, moment of inertia and section modulus for different sections including angle, circle, rectangle, Channel, I-section and T-section. Moment of inertia is required to determine bending stress and deflection of beam.

You can also use our Deflection Calculator Easy to use calculator for different loads on beams

See more about bending moment and shearing force

The links on this page will lead you to available web resources including Lecture notes, products or services in the field of Structural Analysis.

Visit Problem Solver  for solved examples

 

Moment Distribution CalculatorNew

Easy to use calculator for solving  Indeterminate beams with different load

Overhanging Beam CalculatorNew

Bending Moment & Shear Force Calculation for Overhanging beam with different loads

Fixed Beam Calculator

Shear force and bending moment calculations for different loading cases of Fixed beam

RC Beam CalculatorNew

Calculate the strength of reinforced concrete beams

Profile of Civil EngineersNew

Get to know about distinguished civil engineers

CE HorizonNew

Online Civil Engineering Journal and Magazine

 
 

Tell-A-Friend about civil engineering resources

Join the mailing list to get informed about new products or links

 

Applied Mechanics 

Structural Analysis 

Design of Structures

Construction Materials

Engineering Graphics

Disaster Management

Geotechnics

Transportation

Land Surveying

Skyscrapers

Hydraulics

Environmental Engineering

Irrigation Engineering

Offshore Engineering

Construction Management 

Quantity Surveying

Construction Disputes

Construction Technology

Construction Equipments

Research Papers

Journals & Magazines

Construction Companies

Consultants

Professional Societies

Computer Software 

Conferences

Photo Album

Home

Tell-a-friend

Join us

Job Search

Book Store

Scholarships

Colleges & Universities

Learning Support

Last updated on Thursday January 31, 2013