Time for afternoon problems

[TehMightyEngineer]

So, I'm reviewing all the NCEES sample exam problems in a simulated exam format using a 4 hour timer. I'm having REAL trouble finishing the problems even close to the time limit. Part of me suspects this is due to the example exam questions being poorly written and I doubt most people could complete them in time looking at them for the first time. Also, the example answers tend to leave out some things that take time but to me would be required to design the requested design.

For example, problem 602. b) requests "design the beam-to-column connection". Easy enough, there's so many examples that cover this I would be amazed if most people couldn't solve it. There's an example in the AISC 13 CD exampeles that is extremely similar. The only problem is time, that takes a LOT of time. Even using as much AISC manual tables as one can it took me well over an hour. Then looking at the example solution they leave out things I considered to be required; such as beam flexuaral strength at the connection, block shear in the plates, shear in the beam (which doesn't control by inspection but they still didn't mention it), bearing in the bolts in the top and bottom plates due to edge distance, and possibly others that I didn't think of. They also skip a lot of steps in their calculations which I feel would be required to demonstrate competance or completeness. For example they reduce the axial load in the top and bottom plate by 1/3 the axial load (for 3 plates). Makes sense, I actually forgot to do this when doing the example. However, they never show how they calculated the axial load or why they devided it by 3.

I suspect that even if you knew EXACTLY what the problem required and could do all the calculations at your fastest speed, most people still would take over an hour for this problem.

So, my questions:

1) How can anyone know what we're allowed to take as given or allowed to take as acceptable enough detail?

2) Is there something I'm missing that may allow one to solve the problem faster? There's no AISC manual tables I know of that can help out with the top/bottom plate design other than hand calculations.

3) For those who took the SE test already, do the sample questions provide a decent representation of the amount of time each problem will be take or will they generally be faster than the sample exam?

4) Any advice people have on items (tables, chapters, online PDFs, guides, example problems) I should be familar with to help speed up my afternoon problems?

Less than a week...

 

[keiwong]

Ok, on 602the you can neglect the flexural strength because in the problem statement it specifically said to design the rigid moment connection. The flexure of the beam is not one of the items to be checked under section 12 in the manual. If we were responsible for checking that, it would have probably been asked for under the problem statement of part a where they asked for the moment diagram. Section 12 states that the flanges take all the moment and the web takes the shear, so the shear plate connector could be read right off the table in section 10. The answer does show the check for the entire moment plates, so that is expected, I believe you can forgo checking the flange because it is thicker and higher yield than the plate that is connected to it so a failure would occur in the plate before the flange. And the column was checked for required stiffness. I guess in a way by leaving out a couple steps they show that this is the minimum to be considered "acceptable" remember "acceptable" is a much lower bar than say excellent or exceptional

 

[bassplayer45]

1. Just remember, when in doubt, if you dont have time to finish, write out what you planned to do, or would have done if you had time left. On the vertical in october i still probably had 25% of problem 2 left to do and i wrote out a paragraph saying i would have done x, y, z, if i had time left and got an acceptable.

 

[TehMightyEngineer]

keiwong: Makes sense. I did the shear plate using the the tables in 10. I didn't consider ignoring the flanges of the beam as you could easily argue that they don't control by inspection. I also didn't consider that "acceptable" is far from "excellent". That's a good point that I shall consider.

bassplayer45: Oh my goodness, I didn't even consider that. Wow, that's such an amazing piece of advice and I will take that to heart. Doubly glad to hear that you got an acceptable with that approach. I'll make sure that if I know I'll be short on time to write out my steps and just leave the calculations blank. Where's the "buy a beer" button, like isn't strong enough.

 

[dakota_79]

The NCEES sample exam is very representative of both time constraints and level of difficulty of the actual exam. It was wise of you to treat it as a simulated exam and you're much better prepared having done that (even if you did poorly on the simulation!). As you observed, you really don't have time to "learn" how to do anything during the exam - you have to be able to read the problem and visualize right away what steps you need to do, then crank through it. And you'll still be tight on time at that.

bassplayer's advice is excellent. Remember, they're not looking to measure a fresh graduate who is technically proficient in calculating every single limit state of a problem imaginable, they're looking to measure whether you're a competent engineer who shows good judgment.

There's an anecdote buried on the NCEES website or in Structure magazine or somewhere in an article regarding grading of the essay problems, wherein a guy involved in the grading process shared the story of an examinee who went through all the calcs for a problem and biffed it pretty bad, but at the end of the problem the examinee wrote on her exam something like "this is likely wrong, because simple rule of thumb 'x' tells me the answer should be at least in the ballpark of 'y', which isn't even close to my answer. Time permitting, I would go back and find my error(s)." The examinee's calcs indeed were completely wrong, but her rule of thumb was indeed in the ballpark, and more importantly she showed excellent judgement to recognize the error and the need to fix it in "the real world". She was given a perfect score for the problem.

So as McEngr wisely stated on another thread: don't miss the forest for the trees.

Good luck!

 

[keiwong]

One more thing you dont have to do the problems in order right? How would that work?

 

[kevo_55]

^^ You're basically given blank pages and told to write the problem number that you are working on at the top.

Don't be shy about skipping the harder afternoon problems for the easier ones!

 

[bassplayer45]

Corect, you are given 3 booklets of graph paper (for bridge, 4 for building). On the front page it asks you to bubble in which problem you are working on and you are only allowed to write in that booklet for the problem you bubbled. I am looking forward to next saturday, i am seat 1 of 1 with all the EIT's and i get to be "that guy" carrying in all the books. What is the over under on how many people say "we were allowed to bring books?"

In response to the NCEES article, that is very true. They want to make sure you are doing the method correctly and understand the principles. I had a friend who took the OLD format where day 2 was all essays combined. He did a seismic problem and got to the end with a period of vibration of 16 seconds. When he wrote the 16 second answer, they called 1 minute remaining and he literally circled it and wrote "i know this is no where near correct, it should be something like 0.50 based on my experience, i probably made a math error here (drew an error to the area), sorry" and they passed him.

 

[TehMightyEngineer]

dakota_79: Unfortunately I knew everything for the sample test really well. I had a few stumbles on masonry that maybe cost me about 10 minutes but other than that I knew exactly how to solve everything and even where to find examples to double check my method with. Still couldn't finish on time. However, I definitely know what you mean, I'm spending the next week going over my references trying to make sure that I don't have to search for anything. I'm running out of 3M sticky tabs and my highlighter is going dry...

REALLY good to know about that anecdote. I was hoping something like that would be true because a couple of the sample multiple choice questions I rushed through them at the end and got a clearly bogus answer so I simply selected what I knew was close by experience.

kevo_55: Good to know, I was wondering what would happen if it was loose pages and we dropped them. Would they give us time to order it properly? Should I give page numbers? That's good to know that it's multiple booklets. A simple question, I'm finding the NCEES sample exam book does not like to stay open. Is this also true for the actual exam? Are we allowed to bring paper weights?

bassplayer45: Taking the 2nd day? I'm bringing all my books in suitcases, my boss did his with a red wagon. I'm seat 3 so I guess there will be some more structural guys with me. I'm guessing at least 10% of the attendees give you the "book question".

Really good to know about that story. I will take that to heart so as to leave enough time to write out things like that if I have no time or can't get a valid answer.

You guys are making me feel much better. If the problems are as time heavy as the sample exam questions then I guess I should be good enough but it's going to bug the heck out of me to not be able to answer questions I know I can do in my sleep with enough time. Based on the sample test I'll be able to finish all but 1 of the building problems. I'll make sure to read them through first and order them from easiest to hardest. If I run out of time I'll follow your advice here. Thanks everyone, this is a huge help.

 

[Formula1251]

That NCEES sample test book is difficult to keep open! Fortunately in the real exam, you only have the problems you are working for that session. The exam question booklet is thin, and will be fine. Are you taking both days? I gather this is your first time--good luck!

 

[keiwong]

I am taking both days, just wondering how likely is it that we would need to do a full blown moment distribution or matrix method? Or is it more likely they will be like, tmrw moment is this what is the reinforcement?

 

[McEngr]

matrix method - don't waste your time...

moment distribution - you likely will need to solve for one, but it will be simple enough -> 3-span beam with concentrated load on the outer spans.

just make sure you have a tried and true fixed end moment method. I would NOT recommend trying a new method that you're not accustomed to right before the exam. Just do what you know - even if it takes a little longer.

 

[McEngr]

I will say this - since matrix method is based off of virtual work, it is possible that you might see a one-bay, tension-only brace. Solve for the brace or determine the deflection or rigidity of the LFRS.

 

[keiwong]

I will say this - since matrix method is based off of virtual work, it is possible that you might see a one-bay, tension-only brace. Solve for the brace or determine the deflection or rigidity of the LFRS.

Do you think this is more likely in the morning or afternoon?

 

[bassplayer45]

Yes teh, i was lucky enough to pass the vertical portion on my second attempt. day 2 awaits

 

[TehMightyEngineer]

good luck, let's get that passing rate up.

 

[captaincaution]

Don't forget to write out any assumptions you make along the way to simplify a problem. As long as an assumption is reasonable, the graders should accept it.

 

[McEngr]

I will say this - since matrix method is based off of virtual work, it is possible that you might see a one-bay, tension-only brace. Solve for the brace or determine the deflection or rigidity of the LFRS.

Do you think this is more likely in the morning or afternoon?

I think this is likely either a "part (a)" of a multi-part afternoon lateral problem or a full-blown question in the morning. Solving for deflection of a braced frame is relatively quick and easy if you've done it before - especially a single-story braced frame.