Mastering Shear Force and Bending Moment Diagrams
Each lecture is developed and delivered with the benefit of my experience as a university lecturer in structural engineering. The teaching style appeals to all types of learners with material developed through hand-drawn notes and sketches. Students are encouraged to engage with each lecture by actively developing their own notes during each video lecture…no ‘death by PowerPoint’ here! We’ll focus on pinning down the basics before diving into worked examples.
If you follow all lectures and attempt all of the worked examples, by the end of the course you will have an excellent grasp of this essential civil engineering skill!
Section 1: Reviewing the basics
Before we get into the detail of shear force and bending moment diagrams, first we need to do a little housekeeping. We’ll clarify a few assumptions that apply to our analyses and make sure you can determine support reactions for statically determinate structures.
Section 2: Understanding internal bending moments
In this section we start laying the foundation for your understanding of bending moments. We kick things off by considering how the bending moment relates to the state of stress within the structure – we’re trying to answer the question ‘what is the bending moment telling us about the state of stress within the structure?’.
Then we’ll see how the principle of equilibrium allows us to determine the internal bending moment at any point within the structure. This will prepare us nicely to start thinking about how the bending moment changes along the structure.
We’ll wrap this section up with some worked examples to make sure you understand everything we have discussed in the section.
Section 3: Understanding internal shear forces
Everything we’ve done for bending moments we’re going to now do for shear forces:
relating shear stress to shear force
cutting the structure to reveal the internal shear force
introducing a sign convention
As always we’ll confirm you understand everything by completing some worked examples.
Section 4: Differential relationships between loading, shear force and bending moment
In this section we take our understanding to the next level. We’re going to establish the relationships (and rules) that allow us to systematically build bending moment and shear force diagrams – 100% accurately every time. By the time you complete this section, you will understand how these diagrams can be developed in a systematic way, ensuring success every time.
Section 5 & 6: Bringing it all together – Worked Examples
In these final two sections we reinforce everything you have learning so far. Remember, structural analysis, like any other skill only improves through practice. By putting everything you have learning over the previous 4 sections into action here, you’re ensuring the skills are embedded.
We will start on familiar ground in section 5 by considering beam structures. In section 6 we’ll map what you have learned onto frame structures – greatly expanding the applicability of the tools and techniques you have developed in this course!
At this point you can confidently analyse any statically determinate structure you’re likely to come across in your civil engineering studies or career. Next step…statically indeterminate structures!
Quick Review of the Basics
Internal Bending Moments - The Basics
At 12:15 in the following lecture, I draw the tensile force acting on the cross section as an arrow acting to the left. This should actually be an arrow acting to the right - opposite in direction to the compression force. You would have probably realised this was a slip of the pen on my part - but I thought I'd better point it out to avoid any confusion!