A Beginner's Guide to Structural Mechanics/Analysis

Continuous Beam Analysis

(c) 2007, 2008 T. Bartlett Quimby

Section CB.2

Elastic Analysis

Last Revised: 11/04/2014

Classical methods of indeterminate elastic analysis generally all rely on the same basic principles of statics and mechanics.  Other methods use principles of work and energy.  As it is the intent of this text (at this time) to provide basic review support for the component design texts available on this site, we do not go into much detail of the derivation of the various methods.  The intent here is to demonstrate the application of some common methods.

While there are quite a few methods of indeterminate analysis presented in structural analysis texts, this text (for now) will focus on moment distribution as it is an easy hand method that is also very easy to implement in an electronic spreadsheet.

Another common method of indeterminate structural analysis is the stiffness method.  This is the underlying method used in most elastic analysis computer programs on the market.  The method is best used by writing a general computer program.  Most of the commercially available programs now provide full development of shear, moment, and deflection diagrams from all members. 

The basic objective of elastic indeterminate analysis is to determine enough of the reactions and internal forces so that you can use principles of statics to find the remaining internal forces.  Whether you get reactions from a hand method or a computer program, the remainder of the solution for shear, moment, and deflection is easily obtained using statics.