Inertial Hopkinson bar shock sensor
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsWilliam R. Davis, Willard S. Walton
Life of this patent
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Abstract
A device and method for measuring the intensity of high amplitude strain waves caused by the impact of a projectile or the detonation of an explosive on armor plate are disclosed. The sensor may be configured as a shock wave sensor. The shock wave sensor may include a solid, cylindrical bar having a pair of strain gages located at opposite positions on an exterior surface of the bar. The strain gages may be located along one end of the bar proximal to a test specimen such as armor plate.
Claims15
A sensor for use with a test specimen comprising:
- a bar;
- a first strain gage attached to said bar;
- and
- a second strain gage attached to said bar;
- wherein said bar is attached onto a back surface of the test specimen, said bar positioned on the back surface of the test specimen so as to be located directly behind an impact-receiving front surface of the test specimen.
A sensor for measuring the intensity of high amplitude energy waves having amplitude frequencies below 500 KHZ with event durations less than 73 microseconds, the waves resulting from impact of a projectile or detonation of an explosive on a test specimen, said sensor comprising:
- a bar;
- a first strain gage located on said bar;
- and
- a second strain gage located on said bar;
- said bar having first and second end portions,
- said bar positioned directly behind an impact point on a front surface of the test specimen;
- said first and second strain gages positioned at an end of said bar proximal to the test specimen, said first strain gage located opposite from said second strain gage.
A method for measuring the intensity of high amplitude strain waves upon impact of a projectile or detonation of an explosive on a test specimen comprising:
- (1) welding a first end portion of a bar to said test specimen;
- (2) attaching first and second strain gages onto said bar at a first and a second position, respectively;
- (3) orienting said first and second strain gages onto said first and second positions so that said gages are positioned opposite to each other;
- (4) connecting said first and second strain gages in a measurement circuit so as to negate any bending effect on said bar,
- (5) impacting a surface of the test specimen with shock waves;
- (6) measuring longitudinal strain only.
Dependencies are inferred from the claim text.