ASTM F1614-99

1.1 This test method covers the measurement of certain shock attenuating characteristics, rapid rate force-displacement relationships, of materials systems employed in the midsole of athletic footwear intended for use in normal running movements. This test method covers three different procedures for performance of the rapid rate force application: Procedure A for falling weight impact machines, Procedure B for compression force controlled machines, and Procedure C for compression displacement controlled machines.

1.2 The material system response for rapid rate force application may be different for each of the three procedures of this test method.

1.3 This test method is empirically based on the use of an 8.5-kg mass dropped from 50 mm (1.97 in.) to generate peak compressive forces which are comparable to that experienced by a midsole in heel strike tests for normal running movement. This requires the specimen to be rigidly supported and the energy to be delivered through a 45-mm (1.8-in.) diameter flat tup.

1.4 This test method imposes an impulse to generate a rapid rate compressive force-displacement hysteresis cycle and evaluates shock attenuating characteristics of the specimen. The maximum energy applied to the specimen occurs at peak displacement and must be within +10% of a reference value that is used to normalize the data for comparative purposes.

1.5 Shock attenuating characteristics, for this test method, are in terms of absorbed energy loss during the hysteresis cycle, peak pressure, maximum strain, and average stiffness. Each of these characteristics will have varying importance, depending on the design objectives for the material system in the athletic footwear product.

1.6 Test results obtained by this test method shall be qualified by the specimen thickness and the reference maximum energy applied.

1.6.1 Nominal specimen thickness values for this test method are in the range from 5 to 35 mm (0.2 to 1.4 in.), see 7.1.

1.6.2 The standard value for the reference maximum energy applied of this test method is 5.0 J. Other values may be used, if they are clearly stated in the report.

1.7 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.