Oh that is true...it's possible a change in angle impacts longer span bridges faster than shorter span bridges. But I don't take statics, so...bernard wrote:I don't have an answer at this hour but the different spans brings up another question: does the "tilt" have more of an effect for a large angle change involving a short span or a smaller angle involving a longer span? Does span or angle affect the challenge more? I would guess the span's added challenge dramatically increases with greater spans, with greater angles adding more challenge but with less of a magnitude. Just a guess coming from a sleepy person though.nxtscholar wrote:So someone correct me if I'm wrong (I'm a biomathematics major, although one with a strong interest in engineering), but I had a sudden pop into my mind that I'm rather curious about.
Does this year's rules with regards to the test support actually affect division B more and thus pose a bigger challenge to them than division C? Like, by nature of the rules, division C bridges are longer than division B bridges because of a longer mandated span. Consequently, the test support creates a larger angle of inclination for division B bridges than division C bridges. I'm going along the lines of simple geometry. For division C, it's a "rise" of 5 cm to a "run" of 45 cm. For division B, it's about a rise of 5 cm to run of 35 cm.
Thus, doesn't this create a larger change in the direction of forces and stress for division B than division C compared to last year? In other words, don't division B teams have more to change in their designs than division C with regards to changing truss designs, thickness of members, etc.?
I emphasize, however, that regardless of division, the test support doesn't seem to be changing the problem that much. But the question I ask is does division B technically have more to deal with than division C in terms of change?
Bridge Building 2016
-
- Member
- Posts: 261
- Joined: November 14th, 2013, 6:25 pm
- Division: Grad
- State: NJ
- Has thanked: 0
- Been thanked: 0
Re: Bridge Building 2016
- bernard
- Administrator
- Posts: 2499
- Joined: January 5th, 2014, 3:12 pm
- Division: Grad
- State: WA
- Pronouns: He/Him/His
- Has thanked: 186 times
- Been thanked: 795 times
- Contact:
Re: Bridge Building 2016
With the chair setup at the NJIT regional, I think you'd also need some experience with dynamics...nxtscholar wrote:Oh that is true...it's possible a change in angle impacts longer span bridges faster than shorter span bridges. But I don't take statics, so... :Pbernard wrote:I don't have an answer at this hour but the different spans brings up another question: does the "tilt" have more of an effect for a large angle change involving a short span or a smaller angle involving a longer span? Does span or angle affect the challenge more? I would guess the span's added challenge dramatically increases with greater spans, with greater angles adding more challenge but with less of a magnitude. Just a guess coming from a sleepy person though.nxtscholar wrote:So someone correct me if I'm wrong (I'm a biomathematics major, although one with a strong interest in engineering), but I had a sudden pop into my mind that I'm rather curious about.
Does this year's rules with regards to the test support actually affect division B more and thus pose a bigger challenge to them than division C? Like, by nature of the rules, division C bridges are longer than division B bridges because of a longer mandated span. Consequently, the test support creates a larger angle of inclination for division B bridges than division C bridges. I'm going along the lines of simple geometry. For division C, it's a "rise" of 5 cm to a "run" of 45 cm. For division B, it's about a rise of 5 cm to run of 35 cm.
Thus, doesn't this create a larger change in the direction of forces and stress for division B than division C compared to last year? In other words, don't division B teams have more to change in their designs than division C with regards to changing truss designs, thickness of members, etc.?
I emphasize, however, that regardless of division, the test support doesn't seem to be changing the problem that much. But the question I ask is does division B technically have more to deal with than division C in terms of change?
"One of the ways that I believe people express their appreciation to the rest of humanity is to make something wonderful and put it out there." – Steve Jobs
-
- Coach
- Posts: 573
- Joined: February 6th, 2006, 2:20 pm
- Division: B
- Has thanked: 0
- Been thanked: 7 times
Re: Bridge Building 2016
I see where you are coming from, and yes, as the span decreases, the angle of the bridge increases... depending on how you design your bridge... In theory, you could design an elevated bridge, then chop off the elevated legs on one side... In that case, there is no angle due to the elevation change.nxtscholar wrote:So someone correct me if I'm wrong (I'm a biomathematics major, although one with a strong interest in engineering), but I had a sudden pop into my mind that I'm rather curious about.
Does this year's rules with regards to the test support actually affect division B more and thus pose a bigger challenge to them than division C? Like, by nature of the rules, division C bridges are longer than division B bridges because of a longer mandated span. Consequently, the test support creates a larger angle of inclination for division B bridges than division C bridges. I'm going along the lines of simple geometry. For division C, it's a "rise" of 5 cm to a "run" of 45 cm. For division B, it's about a rise of 5 cm to run of 35 cm.
Thus, doesn't this create a larger change in the direction of forces and stress for division B than division C compared to last year? In other words, don't division B teams have more to change in their designs than division C with regards to changing truss designs, thickness of members, etc.?
I emphasize, however, that regardless of division, the test support doesn't seem to be changing the problem that much. But the question I ask is does division B technically have more to deal with than division C in terms of change?
Dan Holdgreve
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
-
- Member
- Posts: 129
- Joined: November 10th, 2013, 6:53 pm
- Division: Grad
- State: MD
- Has thanked: 0
- Been thanked: 0
Re: Bridge Building 2016
The issue with just building an elevated bridge and chopping off one sides legs is the maximum 2cm clearance on the not inclined side. You couldn't build 5cm high legs, since that would be higher than the allowed height of the lower side. You could possibly build 1.5-2cm high legs, but I don't think that would be the most efficient solution to the problem. Though it does make the angle a little smallerdholdgreve wrote:
I see where you are coming from, and yes, as the span decreases, the angle of the bridge increases... depending on how you design your bridge... In theory, you could design an elevated bridge, then chop off the elevated legs on one side... In that case, there is no angle due to the elevation change.
-
- Coach
- Posts: 573
- Joined: February 6th, 2006, 2:20 pm
- Division: B
- Has thanked: 0
- Been thanked: 7 times
Re: Bridge Building 2016
You can if you slope the leg inward, so at the point where the opening starts it is equal to or less than 2 CMdholdgreve wrote:I see where you are coming from, and yes, as the span decreases, the angle of the bridge increases... depending on how you design your bridge... In theory, you could design an elevated bridge, then chop off the elevated legs on one side... In that case, there is no angle due to the elevation change.nxtscholar wrote:So someone correct me if I'm wrong (I'm a biomathematics major, although one with a strong interest in engineering), but I had a sudden pop into my mind that I'm rather curious about.
Does this year's rules with regards to the test support actually affect division B more and thus pose a bigger challenge to them than division C? Like, by nature of the rules, division C bridges are longer than division B bridges because of a longer mandated span. Consequently, the test support creates a larger angle of inclination for division B bridges than division C bridges. I'm going along the lines of simple geometry. For division C, it's a "rise" of 5 cm to a "run" of 45 cm. For division B, it's about a rise of 5 cm to run of 35 cm.
Thus, doesn't this create a larger change in the direction of forces and stress for division B than division C compared to last year? In other words, don't division B teams have more to change in their designs than division C with regards to changing truss designs, thickness of members, etc.?
I emphasize, however, that regardless of division, the test support doesn't seem to be changing the problem that much. But the question I ask is does division B technically have more to deal with than division C in terms of change?
Dan Holdgreve
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
-
- Member
- Posts: 113
- Joined: October 24th, 2013, 3:17 am
- Division: C
- State: NY
- Has thanked: 0
- Been thanked: 0
Re: Bridge Building 2016
Does anybody have anything to say about a trapezoid shaped bridge with no joints around the actual contact point of the loading block and the bridge?
Last minute ideas, thank you.
Last minute ideas, thank you.
Happy to be here
- bernard
- Administrator
- Posts: 2499
- Joined: January 5th, 2014, 3:12 pm
- Division: Grad
- State: WA
- Pronouns: He/Him/His
- Has thanked: 186 times
- Been thanked: 795 times
- Contact:
Re: Bridge Building 2016
Try to include a drawing. I'm not sure exactly what you mean and am thinking of many designs that match what you described.embokim wrote:Does anybody have anything to say about a trapezoid shaped bridge with no joints around the actual contact point of the loading block and the bridge?
Last minute ideas, thank you. :mrgreen:
"One of the ways that I believe people express their appreciation to the rest of humanity is to make something wonderful and put it out there." – Steve Jobs
- Mr_Pep_Band
- Member
- Posts: 11
- Joined: December 15th, 2015, 1:12 pm
- Division: Grad
- State: ND
- Has thanked: 0
- Been thanked: 0
Re: Bridge Building 2016
Hi all, I am new to this forum but competed in Science Olympiad in high school, and have run the Bridge Bruilding/Boomilever/Towers event the last 5 years at North Dakota State competition whilst in college at NDSU. Every year I have facilitated State competition, I try to build 2-3 bridges for fun and to better understand the event and what it takes to win. This year they threw a curve ball at us with the unsymmetrical loading abutments.
Am I correct in how this is laid out in CAD for the C Division with the 5 cm tall abutment on one side and then the max 2 cm height on the other side?
Am I correct in how this is laid out in CAD for the C Division with the 5 cm tall abutment on one side and then the max 2 cm height on the other side?
ND State Competition Facilitator
Towers, Boomilever, and Bridge Building 2011-2016
"A good Design needs to have good Fabrication"
Divison C Competitor 2009
Towers, Boomilever, and Bridge Building 2011-2016
"A good Design needs to have good Fabrication"
Divison C Competitor 2009
-
- Coach
- Posts: 346
- Joined: March 11th, 2014, 12:00 pm
- Division: C
- State: FL
- Has thanked: 1 time
- Been thanked: 21 times
Re: Bridge Building 2016
Mr_Pep_Band wrote:Hi all, I am new to this forum but competed in Science Olympiad in high school, and have run the Bridge Bruilding/Boomilever/Towers event the last 5 years at North Dakota State competition whilst in college at NDSU. Every year I have facilitated State competition, I try to build 2-3 bridges for fun and to better understand the event and what it takes to win. This year they threw a curve ball at us with the unsymmetrical loading abutments.
Am I correct in how this is laid out in CAD for the C Division with the 5 cm tall abutment on one side and then the max 2 cm height on the other side?
Looks correct to me!
-
- Coach
- Posts: 573
- Joined: February 6th, 2006, 2:20 pm
- Division: B
- Has thanked: 0
- Been thanked: 7 times
Re: Bridge Building 2016
yes, your dwg is correct... One thing we were unprepared for at the competition we ran, is that a few teams, in order to get below the 2 cm rule on the one side, had to shift the 5 CM block further off the line in order to properly bear the feet of the bridge on the elevated side... After a careful review of the rules, they do not say that the elevation block must "toe the line." It can be located anywhere in the bearing zone behind the line, so we allowed them to position it wherever they wanted, as long as it was behind the line.Mr_Pep_Band wrote:Hi all, I am new to this forum but competed in Science Olympiad in high school, and have run the Bridge Bruilding/Boomilever/Towers event the last 5 years at North Dakota State competition whilst in college at NDSU. Every year I have facilitated State competition, I try to build 2-3 bridges for fun and to better understand the event and what it takes to win. This year they threw a curve ball at us with the unsymmetrical loading abutments.
Am I correct in how this is laid out in CAD for the C Division with the 5 cm tall abutment on one side and then the max 2 cm height on the other side?
Dan Holdgreve
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
Northmont Science Olympiad
Dedicated to the Memory of Len Joeris
"For the betterment of Science"
Who is online
Users browsing this forum: No registered users and 2 guests