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The following excerpt is taken from a Swiss Federal Nuclear Safety Inspectorate (HSK) publication[1]:
“In the year 1988 a large scale crash test was performed at the US Sandia National Laboratory in which a Phantom military jet with a weight of 19 tons was impacted at a velocity of 774 km/h into an essentially rigid reinforced concrete wall. This was accomplished by using a two-rail rocket sled facility. The test was monitored by the American safety officials of the NRC. The test results were used to evaluate the “Riera approach” for prediction of the impact force-time history of an aircraft impact on a rigid target. The Riera approach was developed at the end of the 1960's in order to determine the effects of an aircraft crash on nuclear power plants. The target consisted of a block of reinforced concrete 7 m square and 3.66 m thick with a total mass of 469 tons (almost 25 times the weight of the military jet). At impact a portion of each wing and tail was sheared off. The remainder of the aircraft was completely destroyed during the impact. Pieces were dispersed over a large area; the dispersion of the water which was to simulate the kerosene, however, was relatively small. Due to the fact that the reinforced concrete wall was mounted on top of an airbearing platform, it was only slightly damaged [my emphasis] – with concrete spalling at the front face of the target. The penetration depth caused by the engines was 60 mm and that caused by the fuselage was 20 mm.”
Video of test available here:
Researchers at the Sandia National Laboratory published a two-part review of the experiment[2][3], in which they noted the following: “Damage to the target was relatively minor indicating that the major portion of the impact energy went into movement of the target and not in producing structural damage.”
I am curious, if the concrete target had not been mounted on top of an airbearing platform but was instead imbedded into the ground, would the structural damage sustained have been significantly greater? If so, could anyone replying to this post please explain why? The fact that the F4 Phantom is much less massive than the concrete target leads me to believe that the difference would probably be trivial, but I am uncertain, hence this post!
I have included some basic information below, however, more detailed data and a comprehensive analysis of the experiment can be found in references [2] and [3].
Modified (some avionics removed, addition of five rocket casings and water to simulate fuel) F4 Phantom impact weight: 12.7 tonnes
Concrete target: 7 m square and 3.66 m thick atop an air-bearing platform with a combined weight of 469 tonnes.
Friction: “insignificant”
Force required to initiate movement of concrete target: 816kg (less than 0.2% of the weight of the target)
Impact velocity: 215 m/s
Penetration depth of engines: 60 mm
Penetration depth of fuselage: 20 mm
Horizontal displacement of concrete target: 1.83 m
References
1. HSK (2003). “Position of the Swiss Federal Nuclear Safety Inspectorate regarding the Safety of the Swiss Nuclear Power Plants in the Event of an Intentional Aircraft Crash”, http://www.ensi.ch/fileadmin/english/files/gus_03_04_03_e.pdf.
2. W. A. von Riesemann et al (1989). “Full-Scale Aircraft Impact Test for Evaluation of Impact Forces Part 1: Test Plan, Test Method and Test Results”, http://www.iasmirt.org/iasmirt-3/SMiRT10/DC_250400 .
3. K. Muto et al (1989). “Full-Scale Aircraft Impact Test for Evaluation of Impact Forces Part 2: Analysis of the Results”, http://www.iasmirt.org/iasmirt-3/SMiRT10/DC_250401 .
“In the year 1988 a large scale crash test was performed at the US Sandia National Laboratory in which a Phantom military jet with a weight of 19 tons was impacted at a velocity of 774 km/h into an essentially rigid reinforced concrete wall. This was accomplished by using a two-rail rocket sled facility. The test was monitored by the American safety officials of the NRC. The test results were used to evaluate the “Riera approach” for prediction of the impact force-time history of an aircraft impact on a rigid target. The Riera approach was developed at the end of the 1960's in order to determine the effects of an aircraft crash on nuclear power plants. The target consisted of a block of reinforced concrete 7 m square and 3.66 m thick with a total mass of 469 tons (almost 25 times the weight of the military jet). At impact a portion of each wing and tail was sheared off. The remainder of the aircraft was completely destroyed during the impact. Pieces were dispersed over a large area; the dispersion of the water which was to simulate the kerosene, however, was relatively small. Due to the fact that the reinforced concrete wall was mounted on top of an airbearing platform, it was only slightly damaged [my emphasis] – with concrete spalling at the front face of the target. The penetration depth caused by the engines was 60 mm and that caused by the fuselage was 20 mm.”
Video of test available here:
Researchers at the Sandia National Laboratory published a two-part review of the experiment[2][3], in which they noted the following: “Damage to the target was relatively minor indicating that the major portion of the impact energy went into movement of the target and not in producing structural damage.”
I am curious, if the concrete target had not been mounted on top of an airbearing platform but was instead imbedded into the ground, would the structural damage sustained have been significantly greater? If so, could anyone replying to this post please explain why? The fact that the F4 Phantom is much less massive than the concrete target leads me to believe that the difference would probably be trivial, but I am uncertain, hence this post!
I have included some basic information below, however, more detailed data and a comprehensive analysis of the experiment can be found in references [2] and [3].
Modified (some avionics removed, addition of five rocket casings and water to simulate fuel) F4 Phantom impact weight: 12.7 tonnes
Concrete target: 7 m square and 3.66 m thick atop an air-bearing platform with a combined weight of 469 tonnes.
Friction: “insignificant”
Force required to initiate movement of concrete target: 816kg (less than 0.2% of the weight of the target)
Impact velocity: 215 m/s
Penetration depth of engines: 60 mm
Penetration depth of fuselage: 20 mm
Horizontal displacement of concrete target: 1.83 m
References
1. HSK (2003). “Position of the Swiss Federal Nuclear Safety Inspectorate regarding the Safety of the Swiss Nuclear Power Plants in the Event of an Intentional Aircraft Crash”, http://www.ensi.ch/fileadmin/english/files/gus_03_04_03_e.pdf.
2. W. A. von Riesemann et al (1989). “Full-Scale Aircraft Impact Test for Evaluation of Impact Forces Part 1: Test Plan, Test Method and Test Results”, http://www.iasmirt.org/iasmirt-3/SMiRT10/DC_250400 .
3. K. Muto et al (1989). “Full-Scale Aircraft Impact Test for Evaluation of Impact Forces Part 2: Analysis of the Results”, http://www.iasmirt.org/iasmirt-3/SMiRT10/DC_250401 .
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