Indeterminate Structures & The Moment Distribution Method

Go Beyond Simple Statically Determinate Structures

Almost all real world civil engineering structures of any significance are indeterminate meaning we can’t simply rely on the trusty equations of static equilibrium. The moment distribution method is one of the most intuitive ways to analyse these structures.

After completing this course you will be well equipped to determine the shear force diagram, bending moment diagram and qualitative deflected shape for any statically determinate or indeterminate structure you’re likely to encounter as a civil engineer. 

Having a fast hand-analysis method for indeterminate structures is invaluable for any good engineer! The analysis of indeterminate structures is all too often left to the computer in civil engineering these days. But as an engineer, if you can’t approximate by hand what the computer is telling – you’re on thin ice! By the end of this course you’ll have given yourself an invaluable skill – the ability to make sensible judgements on a computer analyses! 

Section 1: Establishing the fundamentals

I will start by setting out the fundamental parts of the moment distribution method; explaining each element before using some worked examples to tie them all together. After completing this section you will have a clear analysis procedure to employ. Each worked example concludes with development of a complete shear force and bending moment diagram.

Section 2: Understanding the importance of structural stability

One of the main areas of application for the moment distribution method is the analysis of structural frames. However, before we can start analysing frames, we first need an understanding of structural stability. In this section I will outline some of the common methods employed by civil engineers to ensure lateral stability of their structures. This will equip you for the analysis of frames in the following sections.

Section 3: Applying what you have learned to non-sway frames

Now we will start to really see the power of this analysis technique. We will apply the procedure and techniques from section 1 to the analysis of non-sway or propped structural frames. This will equip you to perform sub-frame analyses commonly required in the design of reinforced concrete frame structures. After completing this section you will be able to analyse some of the most common structural forms employed in civil engineering today.

Section 4: Expanding to consider sway-frames

In this final section we will bring your analysis skills to the next level by introducing you to the analysis of sway frames. Structures expected to undergo significant lateral deflections under loading will experience additional sway moments. Taking proper account of these sway effects is essential for an accurate analysis of the structure. Following an explanation and demonstration of the techniques, you are challenged to complete the analysis of a number of sway frame structures.