bsen14808-20xxsurfacesforsportsareasdeterminationofshockabsorption

bsen14808-20xxsurfacesforsportsareasdeterminationofshockabsorption内容摘要：

finitions For the purposes of this European Standard, the following terms and definitions apply. areaelastic sports surface sports surface, to which the application of a point force causes deflection over a relatively large area around the point of application of the force pointelastic sports surface sports surface, to which the application of a point force causes deflection only at or close to the point of application of the force binationelastic sports surface areaelastic sports surface with a pointelastic top layer, to which the application of a point force causes both localized deflection and deflection over a wider area mixedelastic sports surface pointelastic sports surface with an areastiffening ponent NOTE A mixedelastic sports surface has deflection characteristics between those of an areaelastic surface and a point elastic surface. shock absorption ability of a sports surface to reduce the impact force of a body falling onto the surface NOTE Shock absorption is a physical quantity consisting of damping and resilience due to a certain impact. 4 Principle A weight is allowed to fall onto a spring placed on the test piece and the maximum force applied is recorded. The difference between this force and the maximum force measured on a hard surface is reported as the EN 14808:2020 (E) 5 force reduction. EN 14808:2020 (E) 6 Licensed copy: The University of Hong Kong, The University of Hong Kong, Version correct as of 14/03/2020 06 BSI 5 Test piece For areaelastic and binedelastic sports surfaces, the test piece shall be a sample of the plete surfacing system measuring 3,5 m by 3,5 m, assembled and installed in accordance with the manufacturer’s stated method, on a substrate plying with the manufacturer’s requirements. For pointelastic and mixedelastic sports surfaces, the test piece shall be a piece of the surface of minimum size 1,0 m by 1,0 m, in bination with the supporting layers to be used in service and using the remended method of attachment in accordance with the manufacturer’s instructions. Laboratory test pieces of either synthetic turf or textile materials shall be prepared in accordance with EN 12229. 6 Conditioning and test temperature For tests in the laboratory, condition the test piece for a minimum of 40 h at a temperature of (23 177。 2) 176。 C. Tests on site shall be carried out at the prevailing ambient temperature and humidity, which shall be recorded 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。 0,1) kg with a hardened striking surface guided so that it is allowed to fall smoothly and vertically with minimum friction. Spiral spring, having a diameter of (69 177。 1) mm, whose characteristic, when mounted in the assembly described below, is linear with a spring rate of (2 000 177。 60) N/mm over the range 0,1 kN to 7,5 kN with a hardened upper plate. The spring should have three or more coaxial coils which shall be rigidly fixed together at their ends. This may be achieved, for instance, by milling the spring from a single piece of steel. Adjustable supporting feet, at least 250 mm from the point of application of the load for a point elastic sports surface and at least 600 mm from the point of application of the load for an area elastic sports surface. Steel base plate, having a lower side rounded to a radius of 500 mm。 an edge radius of 1 mm, a diameter (70,0 177。 0,1) mm and a minimum thickness of 10 mm. Metal guiding tube having an internal diameter of (71,0 177。 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。 0,3) kg. Means of supporting the weight, allowing it to be set to the drop height with an uncertainty no greater than 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.。