TABLE OF CONTENTS Anthony Chu, Endevco
At the first Shock and Vibration Symposium in 1947, mechanical shock was defined as a sudden and violent change in the state of motion of the component parts or particles of a body or medium resulting from the sudden application of a relatively large external force, such as a blow or impact. Since then the specific words used have changed somewhat but the meaning remains the same. Most analysts treat shock as a transient vibration. No matter how it is described or what source produced it, the effects of mechanical shock on structures and equipment create major design problems for a wide variety of systems.
Shock measurement is usually accomplished by measuring the acceleration, velocity, or displacement response of the body. Shock measurement is important in studying the effectiveness of protective packaging design, earthquakes, effects of explosive events (pyroshock), effects of handling and or dropping items, transportation environments, many military applications, automotive crash testing and ballistic effects.
Shock measurement usually requires good high frequency response, good linearity and a wide dynamic range. Frequency content can reach 100 kHz and higher, and amplitudes may exceed 100 kg ( ?10 6 m/s 2). Long duration transients may also require good low-frequency response. Two basic categories of shocks may have to be measured, velocity shocks and oscillatory shocks.
Velocity shock has two components: intensity, usually measured in g s (1 standard g=9.80665 m/s 2), and duration, measured in milliseconds. A...
