Hartford Stadium Collapse PDF

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CAD & FEA research on hartford stadium collapse...

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Case Study

2017/18

CAD and FEA- Case Study Student Name:

Student Number

Muhammad Khan

D15122840

Programme (degree):

B-Engineering Tech Mechanical Engineering

Program Code:

DT006/3

Academic Year:

2017/18

Lecture`s Name:

Brendan Walsh

Module:

CAD and FEA

Submission Date:

23rd March, 2018

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Declaration I hereby certify that this material, which I’m now submitting as a part of continuous assessment of CAD and FEA on the course DT006/3, is entirely my own work and has not been submitted in whole or in part assessment for any academic purpose other than fulfilment for that stated above.

Date: 23/03/2018

___________________ Muhammad Zain Khan D15122840

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Table of Contents Declaration .............................................................................................................................................. 2 Mars Probe ............................................................................................ Error! Bookmark not defined. Hartford Stadium Collapse ..................................................................................................................... 4 Airbus A380 .......................................................................................... Error! Bookmark not defined.

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Hartford Stadium Collapse

Figure 1- Hartford Stadium Collapse

On modern models in Hartford Connecticut a light snow storm fell on the night of 18th January,1978, a routine matter in a new England winter. Whereas those four and half inches of wet snow were the straw that broke Hartford stadium roof, in an engineering disaster that was so colossal that it was hard to comprehend. [3][4] It was a very large structure and its dimensions were 360 × 300 feet. The arena had stood for six years under an advanced space truss roof design. It was the second largest of its type in the world at that time. It was considered to be an engineering marvel. More than five thousand fans cheered a hockey game yet that night under the weight of the wet snow the roof suddenly folded and crashed down. This was the first design that was made relying very heavily on the computer software because it was too complicated to calculate using the old methods of slide rule and hand calculations. The computers were still new and the engineers were not as familiar with them as they are today. [3][4] In this case the engineer’s complex computer aided calculations were correct. However, the mistake came in transferring the computers results into the plans that builders could use. The bracing system for the 30-feet roof members was all wrong. The designers and engineers thought that it was bracing the chords at the midpoint i.e. at the 15-foot point. It was an obvious mistake and everyone failed to consider it. The problem showed its sign while construction was in progress but no one could recognize it. The parts didn’t seem to fit even though they 4|Page

Case Study

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were fabricated precisely. So the contractors simply forced things into place. The space frame was deflecting more than 310mm from the expected value. Therefore, the installation of roof fascia panels was proved to be problematic due to level of distortion in the structure. Instead of addressing the problem, it was jacked 25.3m up to the top of pylon. The maximum sag was calculated to be twice as the expected value. Even some public members complained that the structure appears to be excessively deflecting and the client also raised his concern about the structure. But everyone remained unconcerned and put the client at ease by telling them that the stadium was designed using the state of the art software. They were heavily relying on the software and were confident that everything will go well. [3][4] For future perspective, the risk to this kind of projects can be reduced by warning the designers and engineers about the dangers of over-reliance on the computer software’s. In order to combat this over reliance, simple hand calculations should be used to check model results. The engineers should not rely only on the analysis software and should maintain a healthy scepticism. Moreover, perhaps insidiously, sophisticated software can cause over confidence. The user starts to believe that the most advanced the software, the more correct it is. Therefore, despite the opaqueness it introduces, the engineers still start to equate the system complexity with system accuracy. This is what happened in Hartford, despite the complains, everyone was satisfied because they were confident about the software results and did not recognize the problem. Using such high standard software packages can result engineers who do not have the ability to tackle complex analysis simple because they use software to do so. That’s why due to lack of experience, they fail to check such analysis. The companies should hire the engineers after assessing their abilities to work with the software as well as working problems out with the aid of software. This would help the companies to hire the expertise and would reduce the risk of such failures. [3][4] However, software packages have revolutionized the world of engineering and have removed many of the mundane tasks. They have allowed the engineers to analyse the ever more complex behaviours. The software saves time and also allows to efficiently asses the working of the system. In this project software helped the designers to solve complex problems which were hard to be done by the simple engineering methodology. The software package saved a lot of time and also design such a complex structure of its time. It was just the lack of concentration and over reliance that led to this failure. Moreover, the results given by the software were also not transferred accurately to the paper. [3][4]

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The Hartford incident teaches us that no matter how advanced and efficient the software system is, the human error has the power to strip away its advantages. If I ever be a part of such an immense project and any contradictory problem persist i.e. between the software and actual working. I would rather hold back for a while and revisit the software model and would get to the bottom of why there was such a difference between predicted and actual performance. If the problem could have been detected early, it would have saved million of dollars, that were lost as a result of that collapse. [3][4]

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References Main Body Reference 1. Anon, (2018). [online] Available at: https://dit-bb.blackboard.com/bbcswebdav/pid672771-dt-content-rid-3736203_1/courses/MECH3003/Mars%20Probe.pdf [Accessed 16 Mar. 2018]. 2. Pages.suddenlink.net. (2018). Contractor takes blame for math goof that crashed Mars probe. [online] Available at: http://pages.suddenlink.net/anomalousimages/images/news/news537.html [Accessed 19 Mar. 2018]. 3. Journal, D. (2018). Hartford stadium collapse: why software should never be more than a tool to be used wisely. [online] Engineers Journal. Available at: http://www.engineersjournal.ie/2018/01/23/hartford-stadium-collapse-software [Accessed 15 Mar. 2018]. 4. Anon, (2018). [online] Available at: https://dit-bb.blackboard.com/bbcswebdav/pid672771-dt-content-rid-3736204_1/courses/MECH3003/Hartford%20Stadium.pdf [Accessed 22 Mar. 2018]. 5. Calleam.com. (2018). Airbus – A380 – Why Do Projects Fail?. [online] Available at: http://calleam.com/WTPF/?p=4700 [Accessed 11 Mar. 2018]. 6. Anon, (2018). [online] Available at: https://dit-bb.blackboard.com/bbcswebdav/pid672771-dt-content-rid-3736205_1/courses/MECH3003/Airbus%20A380.pdf [Accessed 12 Mar. 2018].

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List of figured references [Figure: 1] En.wikipedia.org. (2018). Phoenix (spacecraft). [online] Available at: https://en.wikipedia.org/wiki/Phoenix_(spacecraft) [Accessed 23 Mar. 2018]. [Figure: 2] Airbus. (2018). A380 Family. [online] Available at: http://www.airbus.com/aircraft/passenger-aircraft/a380-family.html [Accessed 21 Mar. 2018]. [Figure: 3] Anon, (2018). [online] Available at: https://ditbb.blackboard.com/bbcswebdav/pid-672771-dt-content-rid3736204_1/courses/MECH3003/Hartford%20Stadium.pdf [Accessed 22 Mar. 2018].

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