Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New simulation shows 9/11 plane crash with scientific detail

11.09.2002


Engineers, computer scientists and graphics technology experts at Purdue University have created the first publicly available simulation that uses scientific principles to study in detail what theoretically happened when the Boeing 757 crashed into the Pentagon last Sept. 11.


This image was taken from a simulation, believed to be the first of its kind, that merges a realistic-looking visualization with a precise, physics-based animation that shows what likely happened to the Pentagon’s steel-reinforced concrete structure when it was hit by the Boeing 757 last Sept. 11. The simulation, created by a team of engineers, computer scientists and graphics technology experts at Purdue University, could be used as a tool for designing critical buildings – such as hospitals or fire stations – to withstand terrorist attacks. This image shows a representation of the aircraft just before impact. (Departments of Computer Sciences and Computer Graphics Technology, Purdue University)


This image, showing a representation of the aircraft shortly after impact, is another realistic-looking graphic from the same simulation. The simulation shows what likely happened to the Pentagon’s steel-reinforced concrete structure when it was hit by the Boeing 757 last Sept. 11. (Departments of Computer Sciences and Computer Graphics Technology, Purdue University)



Researchers said the simulation could be used as a tool for designing critical buildings – such as hospitals and fire stations – to withstand terrorist attacks.

The simulation merges a realistic-looking visualization of the airliner approaching the building with a technical, science-based animation of the plane crashing into the structure.


"This is going to be a tremendous asset," said Mete Sozen, Purdue’s Kettelhut Distinguished Professor of Structural Engineering. "Eventually, I hope this will be expanded into a model that we can use to help design structures to resist severe impact loads.

"Using this simulation I can do the so-called ’what-if’ study, testing hypothetical scenarios before actually building a structure."

The simulation can be recorded on a DVD and played on an ordinary personal computer.

The software tool is unusual because it uses principles of physics to simulate how a plane’s huge mass of fuel and cargo impacts a building. The plane’s structure caused relatively little damage, and the explosion and fire that resulted from the crash also are not likely to have been dominant factors in the disaster, Sozen said.

The model indicates the most critical effects were from the mass moving at high velocity.

"At that speed, the plane itself is like a sausage skin," Sozen said. "It doesn’t have much strength and virtually crumbles on impact."

But the combined mass of everything inside the plane – particularly the large amount of fuel onboard – can be likened to a huge river crashing into the building.

The simulation deals specifically with steel-reinforced concrete buildings, as opposed to skyscrapers like the World Trade Center’s twin towers, in which structural steel provided the required strength and stiffness. Reinforced concrete is inherently fire resistant, unlike structural steel, which is vulnerable to fire and must undergo special fireproofing.

"Because the structural skeleton of the Pentagon had a high level of toughness, it was able to absorb much of the kinetic energy from the impact," said Christoph M. Hoffmann, a professor in the Department of Computer Sciences and at Purdue’s Computing Research Institute.

Sozen created a mathematical model of reinforced concrete columns. The model was then used as a starting point to produce the simulation.

Hoffmann turned Sozen’s model into the simulation by representing the plane and its mass as a mesh of hundreds of thousands of "finite elements," or small squares containing specific physical characteristics.

"What we do is simulate the physics of phenomena and then we visualize what we have calculated from scientific principles as a plausible explanation of what really happened," Hoffmann said. "We hope that through such simulations we can learn from this tragic event how to protect better the lives of our citizens and the civil infrastructure of the nation."

The simulation may be the first of its kind for merging realistic-looking animation with scientifically rigorous computations.

"Most of the computer-simulated crashes you see in movies or on TV are not realistic from the point of view of physics," said Voicu Popescu, an assistant professor of computer science. "They are designed to be spectacular rather than realistic. What hasn’t been done much, or, to our knowledge hasn’t been done at all, is to create a visualization that looks realistic in the sense that you would recognize the Pentagon and the plane and is, at the same time, true to physics."

The mesh of finite elements in the model require that millions of calculations be solved for every second of simulation. Creating only one-tenth of a second of simulation took about 95 hours of computation time on a supercomputer. Researchers originally used a bank of computers and later worked closely with Purdue’s information technology staff to harness IBM supercomputers at Purdue and Indiana University.

"The majority of the work had to do with producing the right models and then setting up the particular mesh so that we could work out accurately how this scenario unfolded," Hoffmann said.

In the simulation, the plane crashes into the building’s concrete support columns, which were reinforced with steel bars. In this simulation the columns were assumed to be "spirally reinforced," a technique popular in the 1940s in which steel bars were wound around columns in a helical shape. The coiled steel provided added strength to the columns and probably is responsible for saving many lives, Sozen said.

The simulation might be especially useful for engineers who are trying to design reinforced concrete structures that better withstand terrorist attacks or accidents involving aircraft crashes.

"Our focus was on modeling the impact effect of the liquid fuel in the tanks of the aircraft – the amount of energy transferred to the building’s structural load-carrying system, which is mainly the reinforced concrete columns, and the condition of those columns after the impact," said Sami Kilic, a civil engineering research associate who specializes in earthquake engineering.

A major challenge has been learning how to combine commercially available software with the special models needed to simulate an airliner hitting a building, Kilic said.

The Purdue team used commercial software that is normally used by auto manufacturers to simulate car crashes. But adapting the software to simulate the plane crash and then combining the realistic-looking graphics with scientific simulation has been especially difficult, Kilic said.

"Integrating these two animations is uncommon," he said. "We are discovering a new territory. We had some interaction with aeronautical engineers, and they had never heard of this kind of a simulation, with an aircraft hitting a building.

"This kind of a structure/aircraft interaction is not done commercially."

Writer: Emil Venere, (765) 494-4709, venere@purdue.edu

Sources: Mete Sozen, (765) 494-2187, sozen@purdue.edu

Christoph M. Hoffmann, (765) 494-6185, cmh@cs.purdue.edu

Voicu Popescu, (765) 496-7347, popescu@cs.purdue.edu

Sami Kilic, (765) 496-6657, skilic@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Emil Venere | EurekAlert!

More articles from Interdisciplinary Research:

nachricht Investigating cell membranes: researchers develop a substance mimicking a vital membrane component
25.05.2018 | Westfälische Wilhelms-Universität Münster

nachricht New approach: Researchers succeed in directly labelling and detecting an important RNA modification
30.04.2018 | Westfälische Wilhelms-Universität Münster

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>