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.
                Applications of Influence Line Diagram  

Applications of Influence Line Diagram

From the influence line we can determine the response (reaction, shear, moment etc. ) of a structure due to multiple point loads as well as due to uniform load. Influence line also helps in finding the maximum value of a response function.

Response due to Point Load

Response due to single point load = magnitude of load x ordinate of ILD at the position of point load.
Response due to multiple point loads = equal to the algebraic sum of the product of load and the corresponding ordinate of ILD.

Illustrative Example: Consider A simply supported beam (figure 1) having a span of 7 m.
Influence line diagram application
The reaction at support B due to 10 kN load will be equal to (10) x (value of ordinate at 2m from the ILD for RB) = 10 x (2/7) = 20/7 kN.

Similarly the reaction at B due to 5 kN load would be equal to (5) x (value of ordinate at 5 m from the ILD for
RB
) = 5 x (5/7) = 25/7 kN
Reaction at support B due to both the loads = 10 x (2/7) + 5 x (5/7)
                           = 20/7 + 25/7 = 45/7 kN = 6.43 kN

Featured Links

Moment of Inertia calculatorNew

For different sections including I-section and T-section.

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

Profile of Civil EngineersNew

Get to know about distinguished civil engineers

CE HorizonNew

Online Civil Engineering Journal and Magazine

Response due to Uniform Load

Response due to uniform load is equal to the intensity of load multiplied by the area of ILD under the load.

Consider a beam of span 5m shown in figure 2 and loaded with a 3 m long uniform load of intensity 7 kN/m as shown.

influence line application

The value of reaction at B due to this uniform load =

 (intensity of uniform load) x (area of ILD between C and D).

area of ILD between C and D = area of trapezium

=0.5(ordinate at C+ordinate at D) x (length of uniform load)

                      = 0.5 (2/7 + 5/7) (3) = 0.5 (7/7) (3) = 1.5

therefore, Reaction at B = (7) (1.5) = 10.5 kN

Use our online calculator for bending moment & shear force to quickly get the values and solve the problems.

Moment Distribution CalculatorNew

Solving Indeterminate Beams with different loads

RC Beam CalculatorNew

Calculate the strength of reinforced concrete beams

See more about bending moment and shearing force

Quiz on Structural Analysis

Quiz on Structural Design

Visit Problem Solver  for solved examples on deflection



 
 

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

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 Wednesday October 23, 2013