bsen14808-20xxsurfacesforsportsareasdeterminationofshockabsorption-閱讀頁
2024-09-25 11:41本頁面
【正文】 and reported. 7 Apparatus The principle of the apparatus is shown in Figure 1 and consists of the ponents specified in to . Falling weight having a mass of (20 177。 1) mm, whose characteristic, when mounted in the assembly described below, is linear with a spring rate of (2 000 177。 an edge radius of 1 mm, a diameter (70,0 177。 0,1) mm. Testing foot, consisting of the steel base plate, force sensing device, spring and the upper plate (minimum thickness 20 mm, measured at the centre of the plate) together, guided in the guiding tube. The total mass of the testing foot (without guiding tube) shall be (3,0 177。 0,25 mm. Means of conditioning and recording the signal from the force sensing device and the sensors and a means of displaying the record. The channel frequency class of the conditioning amplifier, in accordance with ISO 6487, shall be ≥ 1 kHz. The conditioning amplifier shall be followed by or shall incorporate a lowpass filter having a 2nd order Butterworth EN 14808:2020 (E) 7 characteristic with a 3 dB frequency of 120 Hz. Filtration may be implemented in hardware or software. The response of the system at any given frequency shall be within 177。 2 %. If digital recording techniques are used, the word length shall be ≥ 12 bits, the amplitude of the signal shall be no less than 25 % of the equipment full scale and the sampling frequency shall be ≥ 2 kHz or twice the upper frequency response limit of the amplifier/filter system preceding the digital system, whichever is the greater. A rigid nonvibrating smooth and even concrete floor, which achieves a value of Fr in accordance with . 8 Measurement of reference force, Fr Set up the apparatus so that it is vertically positioned on the concrete floor. Set the height of the lower face of the impact weight (projection) so that it is (55 177。 0,25) kN. If the value lies outside this range, the results shall be considered invalid. Carry out this procedure at intervals no greater than three months. 9 Procedure Set up the apparatus so that it is vertically positioned on the test piece such that the weight falls at least 20 cm from the edge, for pointelastic and mixedelastic sports surfaces, or at least 1 m from the edge, for area elastic and binationelastic sports surfaces. Set the height of the lower face of the impact weight (projection) so that it is (55 177。 10) s giving a total of three impacts. Record the mean value of the peak force from the second and third impacts and denote it as Ft. If further tests are to be carried out on the same sample, each shall be carried out at a new location, no test position being less than 100 mm from any other. 10 Expression of results Calculate the force reduction, R, from the following expression. ?? F ??R = ?1 ? t ? 100 ?? Fr ???where R is the force reduction, expressed as a percentage (%)。 EN 14808:2020 (E) 10 Licensed copy: The University of Hong Kong, The University of Hong Kong, Version correct as of 14/03/2020 06 BSI Fr is the measured maximum peak force for the concrete, expressed in Newtons (N). Calculate the force reduction, R, of a single testing spot as the mean of the force reduction results of the second and third impacts and report the result to the nearest whole percentage number, . 37 %. 1 2 3 4 5 6 8 7 Key 1 guide for the falling weight 2 electromag 3 falling weight 4 upper plate 5 spring 6 guiding tube 7 force sensing device 8 base plate Figure 1 — Artificial athlete apparatus EN 14808:2020 (E) 11 Licensed copy: The University of Hong Kong, The University of Hong Kong, Version correct as of 14/03/2020 06 BSI 11 Test report The test report shall include the following information. a) reference to this European Standard, . EN 14808:2020。s reference, the type of supporting layers and method of attachment and the dimensions of the test piece。 d) force reduction, R。 f) condition of the surface at the time of test, . wet or dry。 Licensing Manager. Tel: +44 (0)20 8996 7070. Fax: +44 (0)20 8996 7553. Email: .。 。 標(biāo) 準(zhǔn) 王 國 網(wǎng) 標(biāo)準(zhǔn) 下載地址 m/week114
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