GB/T 38012-2019 PDF English
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Footwear - Test Methods for Whole Shoe - Impact Shock Attenuating Property
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GB/T 38012-2019: PDF in English (GBT 38012-2019) GB/T 38012-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 61.060
Y 78
Footwear - Test Methods for Whole Shoe -
Impact Shock Attenuating Property
ISSUED ON: AUGUST 30, 2019
IMPLEMENTED ON: MARCH 1, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 4
4 Principle ... 5
5 Test Equipment ... 5
6 Sample and Conditioning ... 7
7 Test Procedures ... 9
8 Test Result ... 9
9 Test Report ... 11
Footwear - Test Methods for Whole Shoe - Impact
Shock Attenuating Property
1 Scope
This Standard stipulates the test methods for whole shoe and shoe sole in impact
shock attenuating property.
This Standard is applicable to whole shoe and shoe sole with the footwear size of 235
and above.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB/T 22049-2019 Footwear - Standard Atmospheres for Conditioning and Testing of
Footwear and Components for Footwear
3 Terms and Definitions
The following terms and definitions are applicable to this document.
3.1 Shock Attenuating
Shock attenuating refers to the process of decreasing peak force with the increase of
time.
3.2 Energy
Energy refers to the ability of applying force and overcoming resistance, which is
obtained through the integral calculation of force and the displacement generated by
force.
NOTE: it shall be expressed in (J).
3.3 Impact Energy
Impact energy refers to the energy which acts on sample during the process that the
sample is under impact compression.
frequency of the force sensor shall at least be: 2,500 Hz.
5.1.6 Displacement sensor: measuring range: 0 mm ~ 60 mm, accurate to 0.01 mm.
The sampling frequency of the displacement sensor shall at least be: 2,500 Hz.
5.1.7 Software acquisition system: the application of the program enables the record
of the time, displacement and force value data during each impact process. In addition,
it enables the presentation of a relevant curve graph of force value-time, displacement-
time, force value-displacement during the impact process. In accordance with the
recorded force value and displacement data, through an integral summation formula
[in which, W signifies energy, expressed in (J); F signifies force value,
expressed in (N); ds signifies displacement, expressed in (mm)]. The system can
calculate the numerical value of energyimpact energy during the impact compression
process; the numerical value of energyenergy return during the impact return process.
The difference value between them is energy absorption.
5.1.8 The waveform during the impact process: the process of the equipment’s force
application can adopt triangular wave pattern for loading and unloading.
5.1.9 Loading and unloading time during the impact process: uniform time on the
forefoot and the heel: loading time: 25 ms; unloading time: 40 ms. Or, in accordance
with the actual demands (for example, motion state: quick start or jump to the ground),
different loading and unloading time may be defined.
5.2 Thickness Measuring Instrument
Measuring range: 0 mm ~ 50 mm, accurate to 0.01 mm. Compression diameter: (10 ±
0.5) mm; intensity of pressure: (29.3 ± 0.1) kPa.
6 Sample and Conditioning
6.1 Sample
6.1.1 Sample quantity
Sample of whole shoe or shoe sole shall be not less than 1 pair.
6.1.2 Sample preparation
6.1.2.1 Pre-treatment
In terms of shoe sole sample: pre-treatment is unnecessary.
In terms of whole shoe sample: along the bottom line of the upper part, cut off the
upper part of the shoe. If there is a movable inner sole, double-sided adhesive tape
reference standard environment that complies with GB/T 22049-2019; adjust it for at
least 4 h.
7 Test Procedures
7.1 Connect the central points of the test locations selected in 6.1.2.2, prolong it to
intersect with both ends of the circle. Respectively measure-take the thickness of the
test central location of the forefoot and the heel, and the thickness of the intersection
part with the circle. Take the average value of the thickness of the three points as the
original thickness B of the test part, accurate to 0.1 mm.
7.2 Fixate the shoe sole, so that the marked impact location is directly below the impact
head. Make sure that the central point of the test location and the center of the impact
head align with each other; pre-apply (10 ± 2) N of force to fixate the sample.
7.3 Select a suitable displacement impact pattern or force impact pattern; conduct pre-
impact of the sample for once, then, check whether the impact force value can reach
2,300 N ~ 2,500 N.
7.4 In accordance with the pre-impact force, adjust the impact pattern, so that the
maximum impact force that the sample receives can be between 2,300 N ~ 2,500 N.
Impact adjustment shall not exceed 5 times, otherwise, the sample needs to be
replaced, or, place the sample for 4 h, then, conduct the impact test.
7.5 After placing the sample still for 1 min, in accordance with the impact pattern
adjusted in 7.4, conduct 30 times of cyclical impact on the sample; guarantee that the
maximum impact force in the 30th time reaches (2,300 ± 200) N.
7.6 After the test is completed, take down the sample. Record the force value,
displacement, time, impact energy, energy absorption, energy return and average
stiffness during the 30th impact process. In addition, observe appearance variation of
the sample.
8 Test Result
8.1 Record the maximum compression deformation value and the maximum impact
force of the test location, which shall respectively be accurate to 0.1 mm and 0.1 N.
8.2 Deformation rate of the sample shall be calculated in accordance with Formula (1),
accurate to 0.1%:
Where,
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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