HigherEd 2.0

Exam 3 will take place on Monday April 20, 6-8 pm in a location TBD. The content of the exam is restricted to Chapters 7 and 8 only (and only the material we have actually covered out of those chapters–Sec. 7.1-7.4, and 8.1 and 8.2)! You can bring 1 sheet of 8.5 x 11 paper with writing on both sides, a pencil, eraser, and calculator. I expect to have no more than 4 problems, and (depending on how complicated they end of being) perhaps fewer than 4.

This table summarizes the relevant digital materials for this exam (click here to access the “Publisher’s Videos”):

Note that some of this content is re-purposed from last Spring’s class, since I have not had time to do nice recordings of this year’s lectures. But last year’s are fairly similar, so they still hold a good bit of value. Also, I forgot the Pulse pen one day, so we are missing the audio recording of one lecture. As always, use this post as an open thread for discussion.

There’s always a but. We decided yesterday in class that we would have no more collected homework this semester, and we would instead use the time for the project. But you did ask for some suggested problems out of Ch. 8 and 9, so here they are:

Ch. 8: 8-26/27, 8-34, 8-37 (looks alot like one we solved in Ch. 1), 8-45/46, 8-49/50

Ch. 9: 9-41/41, 9-46/47, 9-81/82, 9-95

Remember also that there are 7 videos on the publisher’s website for Ch. 8 and 12 (yes, 12!) for Ch. 9. So you have lots of resources here…and speaking of resources, some of these problems might make excellent choices for your project.

This homework is due on Friday April 3 at NOON. No late homework will be accepted. There are only two problems, both of which will support your quiz preparation and your general understanding of the material in Ch. 7.

Problem 7-26, 7-54

Note that 7-26 really is a shear STRESS problem, even though the problem statement says the boards are glued together. For force calculations, you can consult Ex. 7.2 (p. 396). As always, use this post as an open thread…

This homework is due on Monday March 30 at NOON. Please be in class on time, because NO late homework will be accepted. Just a few problems on shear stress and shear flow.

Prob. 7-28, 7-42, 7-51

Only three problems, but each will require some effort. There are two nice shear flow examples on the publisher’s website. Use this post as an open thread for discussion.

I found this on my hard drive this morning, it’s the solution to a statically indeterminate problem in torsion. Gives some good examples of how to execute these problems.

 

 Video solution: Prob. 5-76: Play Now | Play in Popup | Download

Exam 2 will take place on Monday March 23 from 6-8 pm. We will be in MEC 205. The content of the exam is everything we’ve covered in chapters 5 and 6 of the book. I expect to have 4 problems, and I will write the exam so that time will hopefully not be a significant factor for you.

This table summarizes the relevant digital materials for this exam (click here to access the “Publisher’s Videos”):

Some notes: I forgot the pulse notebook for Module 14, so it’s not available. And I have not had a chance to record the module on unsymmetric bending for this semester, so I am actually pointing you to last year’s Module 14, 15 (in the interest of time, and getting the information you need). (I’m trying to catch up with the recording, but haven’t yet.)

Other administrative functions. You can bring 1 sheet of paper (8.5 x 11) with writing on BOTH side. Use it to write formulas, equations, examples, etc. Also, bring a calculator and a PENCIL with ERASER. We will be taking the exam using Prof. Bloomfield’s TPEGS tablet grading system, so be prepared to bubble in the forms.

Since you all have a big workload this week, the homework assignment is fairly light. Remember, this assignment is due at NOON on Friday 3/20, and NO late homework will be accepted. As usual, please don’t come to class late and expect that your homework will be accepted.

All from Chapter 7 on transverse shear: Prob. 7-5, 7-18, 7-29

There are three nice videos on the publisher’s website to support you as you work through these problems. And for Prob. 7-5, you might consult Ex. 7.2 (p. 396) if you need advice on the calculation of shear force resisted by the web. And use this post as an open thread for discussion.

Funny story. You’re gonna laugh hard about this one…uh, well, seems that I made a huge mistake while solving this problem. I actually recorded this one last year as a cold one, but it’s still as relevant as ever for this semester. So I made a mistake (can you find it?) then I sort of struggle through the trouble-shooting until I find and correct the mistake. I show you this because I run through a bunch of different possible sources of error, and then explore each one as I work to find the right answer. I hope that you can learn by listening to me stumble through this.

 

 Video solution: Prob. 6-123: Play Now | Play in Popup | Download

Introduction to bending. This is a good one! The discussion about the radius of curvature, the nature of the deformation, the neutral axis, and all the rest…there’s alot of good mechanics here. There is an important but slightly less energetic discussion of sign conventions. In any case, the mechanics here are important, because bending is a subject in which physical intuition (and its corroboration via a careful mathematical analysis) can be very important. So getting your signs right is pretty important. The flexure formula is the punchline here, and it will remain with us for the rest of the semester.

 

 Lecture 13: Bending basics: Play Now | Play in Popup | Download

This is a mashup of strength of materials content and statics content. It’s really a bridge lecture from Chapter 5 to Chapter 6, and as such it contains some of each. Have a look at the stress concentration stuff (just like in Ch. 4), and then spend some time reflecting on the shear and moment stuff. If you are not comfortable with the shear and moment analysis, consult your statics notes or check out the solutions on the publisher’s website. And of course if you need more help, let me know.

 

 Lecture 12: Stress concentrations (torsion), V & M: Play Now | Play in Popup | Download