Bending Objects?

Just wondering how to make a slight bend on an object like the picture below.

This is what I have done so far. I am using AutoCAD 2015 Figure 3.1-8.dwg

Instead of extruding the flat, extrude in the transverse, after creating a profile that recreates the slight bends.

I can think of three ways to accomplish this, but I'm at work so my time is limited. I'll see if I can post something tonight unless someone else beats me to it.

You could sign up for my Statics class.

Doesn't statics deal with rigid bodies that do not bend?

As previously suggested, to get your plates to "bend" you start with a different 2D profile. Then you can give it a height.

I assume you want this to look as accurate as possible so I would suggest you put holes in your plates and create a bolt with a separate nut to be copied to each hole.

Note: My drawing is for demonstration purposes only and is not meant to be an exact duplicate of yours.

If you would like a copy of the drawing file itself just let me know. I'd be happy to attach it to a subsequent post.

The same drawing with a Conceptual visual style. Clearer now?

Yikes! Just noticed I have two sets of plates with holes and no bolts instead of one. My bad. Haven't had my ten cups of coffee yet.

A close-up view of the back of the plates.

Doesn't statics deal with rigid bodies that do not bend?

Well, this problem in particular is near the end of the semester and serves as a lead-in to my following semester FEA class.

Statics and Strength of Materials 7th ed. H.W. Morrrow Chap 18, Pg.446 Problem 18.1.

This happens a lot where I tie follow-on classes together.

For example in Statics class we calculate friction force impending motion where a box is just about to slide up or down an inclined plane. Dry stuff with just classical calculations. Now let's test our calculated results in Dynamic Simulation. Introduction in the Statics class to the Dynamics class to follow. 21st century software tools that bring this stuff to real meaning, not just some abstract numbers on a sheet of paper. More like the real world.

You could sign up for my Statics class.

 

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If I can fit that to my schedule next semester I will. This is my last year.

ReMark, Once again thank you!

With the increased pressure to add more to the engineering curriculum we also have expanded our statics course beyond stationary rigid bodies by combining it with a first course in dynamics. Although some of statics and dynamics concepts are covered in the physics courses student have already taken, the geometry aspect of introductory physics courses is minimal. I have found that the geometry component of engineering mechanics problems in statics and dynamics is something with which many students struggle. Inventor is a great tool for exposing students to dynamic analysis and FEA. In addition, the constraint requirements of building a sketch and assembly in Inventor provide great interactive feedback of the implication of various type of constraints and really give meaning to degrees of freedom. The combination of statics and dynamics into one course yields a very fast paced class. There’s little time to bring CAD into the mix. It sounds like you have merged statics, strength of materials, with a touch of dynamics.

I have used my advanced CAD classes to complement what students have learned in engineering mechanics courses. I have an Inventor model of a universal joint that I use in a CAD lab. It is great for understanding assembly constraints and for analyzing the relationship between input and output angles. I give the students the universal joint part files and they have to assemble them. It is interesting to watch what can go wrong in creating this relatively simple assembly and then animate it with a drive constraint. A better understanding of constraints is also beneficial in FEA. I find that incorrect constraints are the most common error in a student's finite element model. Most of my structural engineering colleagues have no idea of the existence of constraint-based CAD modeling and the benefits it can provide engineering students. They still look at CAD as a drafting tool.

I find that Autolisp is great for reinforcing concepts of vector math. Although the Autolisp syntax is rather cryptic I can get students up to speed with it quickly and focus on such concepts as transformation matrices (which are easy to extract from an AutoCAD block), as well as Bezier and B-splines. Simple concepts like unit vectors become much more real when a student can query an AutoCAD drawing for the location of a point that is the result of a vector operation. I find the details of NURBS math to be beyond most students but that it sufficient to explain them as a ratio of B-Splines. Knowing the basic concepts of NURBS provides benefit when students explicitly use them in 3DS Max or implicitly use them in Inventor or AutoCAD.

I hope you don’t mind me getting off topic a bit but this has been fun.

With the increased pressure to add more to the engineering curriculum....

I have started using Autodesk ForceEffect quite a bit in my Statics class. The students are supposed to have already covered all the basic math in their math and again in their physics class, so I had to ask others, "Why am I doing this again?" The response, "They didn't get "it" in those classes." So now you want me to use the same classical failed approach? Funny thing is, I have been able to add a tremendous amount of new content in a way that brings the book problems "alive". Where I used to pick out a handful of problems to illustrate - it would take so long to set up the calculations, that only a handful could be done. And what do we end up with - a bunch of abstract numbers that have little real-world relevance to the students. Because I start out in single part FEA and then assembly FEA I think it would be better to combine our Statics with Dynamics in a single course to run concurrently with the FEA class. I have already made plans to do this curriculum change.

Most of my structural engineering colleagues have no idea of the existence of constraint-based CAD modeling and the benefits it can provide engineering students. They still look at CAD as a drafting tool.

These software tools are now full-featured digital prototyping design tools - drafting is almost a by-product. I was doing a problem with my students last year from a book that the author makes a statement, "But by using traditional techniques, the student can concentrate on the kinematic theories and will not be "bogged down" with learning CAD commands." Sounds to me like the author didn't have the aptitude for setting up DOF sketches. We searched and found the mechanism already modeled on GrabCAD and made it "come to life". Didn't get "bogged down" by anything!

I hope you don’t mind me getting off topic a bit but this has been fun.

We should take this discussion off-line, there might be some areas we could collaborate on.

jmather_at_pct_dot_edu

Edit:

I had to add this image from my final exam. Note that I instruct the students to add a non-existing (in real-world) constraint to the problem so that the results numbers match the simplified hand-calculations from the book's classical solution (which we have set up in an Excel spreadsheet). (I just now added the red underline.)

Don't take it offline, just make a new thread!! I'd love to listen in.

Don't take it offline, just make a new thread!! I'd love to listen in.

so would I, I often find JD's posts enlighten.

(please put some new posts in the inventor thread someday)

Me three! And I second the suggestion to continue your Inventor 101 series.

I too would also like to listen in!!!

And I second the suggestion to continue your Inventor 101 series.

Been too busy. I'm actually busier in the summer when I'm "off" than during the school year.

Classes restart in 2 weeks.

Been too busy. I'm actually busier in the summer when I'm "off" than during the school year.

Classes restart in 2 weeks.

Summer flew by!

I leave tomorrow for a cross country road trip so I will have to wait until September to continue this discussion. I wish you all an enjoyable August. lrm

Make sure you don"t unintentionally bend any objects, have a safe and enjoyable trip.