CONTAINING SHOCK WAVES GENERATED IN EXPLOSIONS BY: CHIRAPHA ANANTAPHATHANAWONG

CONTAINING SHOCK WAVES GENERATED IN EXPLOSIONS BY: CHIRAPHA ANANTAPHATHANAWONG

BLAST WAVES Adam, Sharon. Blasting. Retrieved from https://legionmagazine.com/en/wpcontent/uploads/2011/10/boominsetillustration.jpg

SHOCK WAVES Youtube.com

BLAST EFFECTS As the shock wave expands, pressures decrease rapidly over time. Explosion is highly compressed air that expands until reaching equilibrium with surrounding air. Explosive detonations create an incident blast wave, characterized by an instantaneous rise from atmospheric pressure to a peak overpressure. Needham CE (2010) Blast waves. Springer, Heidelberg

FACTORS ON MAGNITUDE AND DISTRIBUTION OF BLAST LOADS ON STRUCTURE Explosive Properties Location of the detonation relative to structure Reinforcement of the pressure pulse through its interaction with the ground or structure Retrieved from http://lem.ch.unito.it/didattica/infochimica/2008_esplosivi/properties.html. Retrieved from http://911blogger.com/sites/default/files/figure6.jpg.

BUILDING DAMAGE Direct Air-Blast Effects Damage caused by high-intensity pressures of the air-blast close to the explosion Progressive Collapse After air-blast effects, it leads to the failure of exterior walls, windows, floor systems, columns, and girders. Retrieved from http://www.cngspw.com/doc/data.webnotebooks2010/07/20100728121216/fig2_13.gif Retrieved from http://911research.wtc7.net/disinfo/collapse/docs/progressive.gif

BUILDING DAMAGE Blast Pressure affects to the structural. Retrieved from www.fema.gov

INJURIES FROM BLAST WAVES

CASE STUDY

BRODE S ANALYSIS Peak Static Overpressure pp ss = 6.7 ZZ 3 + 1 bbbbbb, wwwwwww pp ss > 10 bbbbbb pp ss = 0.975 ZZ + 1.455 ZZ 2 + 5.85 ZZ 3 0.019 bbbbbb, wwwwwww 0.1 < pp ss < 10 bbbbbb Z is scaled distance: ZZ = RR ww 1 3 R is distance from the charge center in meter W is the charge mass expressed in kilograms of TNT

BLAST WAVES FROM OTHER SOURCES Example: Given: 100 kg charge of RDX TNT Find: Equivalent mass in Solution: 100 x 1.185 = 118.5 kg of TNT

BRODE S ANALYSIS Peak Static Overpressure pp ss = 14.072 ZZ + 5.540 ZZ 2 0.357 ZZ 3 + 0.00625 ZZ 4 bbbbbb, 0.05 ZZ < 0.3 pp ss = 6.194 ZZ 0.326 ZZ 2 + 2.132 ZZ 3 bbbbbb, 0.3 ZZ 1 pp ss = 0.662 ZZ + 4.05 ZZ 2 + 3.288 ZZ 3 bbbbbb, (1 ZZ 10)

CASE STUDY SOLUTION Given: W = 5 kg of TNT R = 5 m Find: Solution: Peak Static Overpressure, pp ss ZZ = RR 1 3 = 5 mm 5 kkkk WW 1 3 = 2.924017738 2.9

CASE STUDY SOLUTION Since Z = 2.9, so Z is between 1 and 10 pp ss = 0.662 ZZ + 4.05 ZZ 2 + 3.288 ZZ 3 bbbbbb = 0.662 2.924 + 4.05 2.924 2 + 3.288 2.924 3 = 0.831611689 0.832 bar = 83.2 kpa

CONCLUSION FROM CASE STUDY ZZ = RR ww 1 3 pp ss = 14.072 + 5.540 ZZ ZZ 2 0.357 ZZ 3 + 0.00625 ZZ 4 0.05 ZZ < 0.3 bbbbbb, pp ss = 6.194 ZZ 0.326 ZZ 2 + 2.132 ZZ 3 0.3 ZZ 1 bbbbbb, pp ss = 0.662 ZZ + 4.05 ZZ 2 + 3.288 ZZ 3 bbbbbb, (1 ZZ 10) Retrieved from http://www.radshelters4u.com/blast1.jpg Increasing in distance from the explosive to the building causes the peak static pressure to decrease More explosive mass causes the peak static pressure to increase.

EXPERIMENT METHODS EXPLOSIVE FIELD-TESTS SHOCK TUBE EXPERIMENT Retrieved from http://www.cal-av.com/pics/test-range/pixa.jpg Retrieved from http://www.ucalgary.ca/johansen/files/johansen/images/shocktube.png

CONCLUSION Blast waves from explosion can cause catastrophic damage Building damage Injuries Understanding shock waves is important first step of the project Pressure wave decrease over time after the blasting Blast wave instantaneous rises from atmospheric pressure to peak overpressure From the case study, it shows that the peak static overpressure depends on the mass of explosive and distance between explosive and structure. Experiment methods Explosive field test Shock tube experiment The project still needs more research and testing

REFERENCES Bangash, M. Y. H., and T. Bangash. Explosion-resistant Buildings: Design, Analysis, and Case Studies. Berlin: Springer, 2006. Print. Needham, Charles E. Blast Waves. Heidelberg: Springer, 2010. Print. Shukla, A., Y. Rajapakse, and Mary Ellen. Hynes. Blast Mitigation: Experimental and Numerical Studies. New York, NY: Springer, 2014. Print. Smith, P. D., and J. G. Hetherington. Blast and Ballistic Loading of Structures. Oxford: Butterworth- Heinemann, 1994. Print. Structures to Resist the Effects of Accidental Explosions. Washington, D.C.: Depts. of the Army, the Navy, and the Air Force, 1969. Print.

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