DRDC Suffield Deminer Visor Trials

Transcription

1 DRDC Suffield Deminer Visor Trials Dr. Chris Weickert Coordinator Physical Protection Sector 3 March 2009 Defence Research and Development Canada Recherche et développement pour la défense Canada Canada

2 Project: Testing of Heat Treated Visors DRDC Suffield Trial Objectives: Conduct V 50 and V proof tests on visors Conduct blast testing on new, scratched, scratched and heat treated visors Report findings

3 Scratch & Heat Treatment Procedures Scratch Treatment: Manual abrasion of visor surface using hand full of sand until visor is opaque Heat treatment gentle heat application to surface using McMaster-Carr 1500 W variable temperature heat gun. Surface heated until slight liquification of surface results in melting of top layer and removal of scratches

4 Equipment to be Evaluated Security Devices (Pvt) Ltd Visor 5 mm polycarbonate heat-formed visor with ballistic polyamide headframe

5 V 50 and V proof Testing 1.1 g Fragment Simulating Projectile (FSP) V 50 test: 17 grain FSP threat (type 1) test for each of the following visors: a) original visor from manufacturer b) scratched visor c) scratched and heat treated visor V proof test: 12 gauge shotgun using sand as the threat, using the method developed by DRDC Suffield/Biokinetics for the visors a) through c) above

6 V 50 Headform for Ballistic Test

7 Strike Velocity vs Residual Velocity NEW SCRATCHED REPAIRED 300 Vr (m/s) Vs (m/s)

8 V 50 Test Results Visor Condition V 50 (m/s) New Scratched Scratched & Heat Treated V 50 Test Results Summary Std Dev (m/s)

9 AP Mine Blast Characterization characterize the soil eject threat from buried AP mines potential evaluation methods using soft tissue stimulants the assess upper body deminer protection systems against the secondary fragmentation threat

10 Particle Velocities Speed (m/s) sand gravel when soil debris hit the mannequin face Time (ms)

11 Development of a Laboratory Test to Reproduce the Effects of Soil Ejected from AP Blast Mines to Test PPE Can reproduce damage caused by AP mines in laboratory conditions More realistic than current ballistic tests used to test PPE 20/40 sand cotton propellant

12 Blast Testing Hybrid III 5% North American female mannequin, in kneeling position, 0.6 m standoff to buried charge

13 Testing Platform and Positioning Rig

14 Trial Test Site Setup & Instrumentation Heated Inflatable Tent Mannequin with Apron

15 Charge Configuration 200 gram C4 charge in standardized AP mine charge container 20/40 sand overburden

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17 Visor Blast Test Results Visor Description Charge Size Reference Pressure (psi) Visor Outcome New 1 New 2 New 3 + apron New 4 + apron New 5 + apron Baseline established 200 g 100 g 100 g 150 g 100 g At No apron broke broke did not break broke broke New 6 New 7 New 8 New Did not break Did not break misfire Did not break Did not break 1B scratched 2B scratched 3B scratched 4B scratched Broke Did not break Did not break Did not break 1A scratched, heat treated 2A scratched, heat treated 3A scratched, heat treated 4A scratched, heat treated Broke Broke Broke Broke

18 Visor Blast Testing Post-Trial Photographs

19 CONCLUSIONS Scratching the visors did not appear to have any detrimental effects on the blast resistance of the visors under test. The proposed heat treatment of the scratched visors appears to degrade the blast resistance of the visors under test. All of the visors, including new ones were broken during blast tests using charge sizes half the size recommended by the relevant standards. Neither the scratching nor the heat treating processes appear to have any detrimental effects on the V 50 performance of the visors under test. The V 50 ratings for new, scratched and heat treated visors fall within the 225 m/s -250 m/s range. Contrary to popular opinion, there is actually no requirement to have visors achieve a V 50 rating of 450 m/s. There is a need to investigate whether the CEN Workshop agreement should allow substitutions for TNT, and if so, what equivalency criteria should be applied.

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