Editing Shock (mechanics) (section)

==Shock measurement==
Shock measurement is of interest in several fields such as
*Propagation of heel shock through a runner's body<ref>{{cite journal
 | last =Dickensen
 | first =J A
 | title = The measurement of shock waves following heel strike while running
 | journal = Journal of Biomechanics
 | volume =18
 | issue =6
 | pages = 415–422
 | date =1985
| doi=10.1016/0021-9290(85)90276-3
| pmid =4030798
 }}</ref>
*Measure the  magnitude of a shock need to cause damage to an item: '''fragility'''.<ref>ASTM D3332-99(2010) Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines</ref>
*Measure shock attenuation through athletic flooring <ref>ASTM F1543-96(2007) Standard Specification for Shock Attenuation Properties of Fencing Surfaces</ref>
*Measuring the effectiveness of a [[shock absorber]]<ref>{{cite journal
 | last =Walen
 | first =A E
 | title = Characterizing Shock Absorbers for Ground Vehicle Simulation
 | journal = JTE
 | volume =23
 | issue =4
 | publisher =ASTM International
 | date =1995
| issn =0090-3973
}}</ref>
*Measuring the shock absorbing ability of package [[cushioning]]<ref>ASTM D1596-14 Standard Test Method for Dynamic Shock Cushioning Characteristics of Packaging Material</ref>
*Measure the ability of an athletic helmet to protect people<ref>ASTM F429-10 Standard Test Method for Shock-Attenuation Characteristics of Protective Headgear for Football</ref>
*Measure the effectiveness of [[shock mount]]s
*Determining the ability of structures to resist seismic shock: earthquakes, etc.<ref>ASTM STP209 Design and Tests of Building Structures: Symposiums on Seismic and Shock Loading Glued Laminated and Other Constructions.</ref>
*Determining whether personal protective fabric attenuates or amplifies shocks<ref>{{cite journal
 | last =Gibson
 | first =PW
 | title =Amplification of shock Waves by Textile Materials
 | journal =Journal of the Textile Institute
 | volume =86
 | issue =1
 | pages =167–177
 | date =1983
 | url =http://nsrdec.natick.army.mil/LIBRARY/90-99/R95-42.pdf
 | access-date =14 February 2015
 | archive-date =27 December 2016
 | archive-url =https://web.archive.org/web/20161227165837/http://nsrdec.natick.army.mil/LIBRARY/90-99/R95-42.pdf
 | url-status =dead
 }}</ref>
*Verifying that a Naval ship and its equipment can survive explosive shocks <ref>{{Citation
 |title       = Shock Design Criteria for Surface Ships
 |volume      = NAVSEA-908-LP-000-3010
 |issue       = Rev 1
 |publisher   = US Navy
 |date        = 1995
 |url         = http://www.vibrationdata.com/tutorials/NAVSEA_shock.pdf
 |access-date  = 14 February 2015
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20150214045155/http://www.vibrationdata.com/tutorials/NAVSEA_shock.pdf
 |archive-date = 2015-02-14
 }}</ref><ref>"MIL-S-901D (NAVY), MILITARY SPECIFICATION: SHOCK TESTS. H.I. (HIGH-IMPACT) SHIPBOARD MACHINERY, EQUIPMENT, AND SYSTEMS, REQUIREMENTS FOR"</ref>

Shocks are usually measured by [[accelerometer]]s but other [[transducer]]s and high speed imaging are also used.<ref>{{Citation | title=High-speed Imaging of Shock Wave, Explosions and Gunshots | publisher=American Scientist | volume=94 | issue=1 | year=2006 | pages= 22–31 | first1=Gary S. | last1=Settles}}</ref> A wide variety of laboratory [[instrumentation]] is available; stand-alone [[shock data logger]]s are also used.

Field shocks are highly variable and often have very uneven shapes.   Even laboratory controlled shocks often have uneven shapes and include short duration spikes;  Noise can be reduced by appropriate digital or analog filtering.<ref>ASTM D6537-00(2014) Standard Practice for Instrumented Package Shock Testing For Determination of Package Performance</ref><ref>{{Citation
 |last        = Kipp
 |first       = W I
 |title       = INSTRUMENTATION for PACKAGE PERFORMANCE TESTING
 |publisher   = International Safe Transit Association
 |series      = Dimensions.02
 |date        = February 2002
 |url         = http://www.kippllc.com/Instru%20for%20Pkg%20Perf%20Testing.pdf
 |access-date  = 5 Feb 2015
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20150207050923/http://www.kippllc.com/Instru%20for%20Pkg%20Perf%20Testing.pdf
|archive-date = 2015-02-07
 }}</ref>

Governing [[test method]]s and specifications provide detail about the conduct of shock tests. Proper placement of measuring instruments is critical.  Fragile items and packaged goods respond with variation to uniform laboratory shocks;<ref>ASTM Research Report D10-1004, [[ASTM International]]</ref> Replicate testing is often called for. For example, [[MIL-STD-810]]G Method 516.6 indicates: ''at least three times in both directions along each of three orthogonal axes".