GB 30228-2013requirements and test methods for impact attenuation of playground surfacing (English PDF)

5.1.2 Test Equipment

5.1.2.1 Principle

Simulated head from different heights on the ground impact test, shock received by the acceleration sensor signal, the data processing to get a head loss Injury evaluation value (HIC values) and the maximum acceleration value (Gmax value). Draw HIC value of each impulse, Gmax value and impact height curve, Select the HIC value of 1000 and a value of 200g Gmax corresponding impact height as measured in the low ground of a critical drop height.

According to equation (1).

HIC (t1, t2) = (t2-t1) t2-t 1integral t2 t1 adé êê úút 2.

max

Where.

a --- acceleration to the gravitational acceleration g multiple representation;

t1, t2 --- t1 and t2 are any two intermediate value between the start time and end time. Time in milliseconds (ms).

NOTE. In the sampling period, the sampling frequency is not lower than 8000Hz, the impact of the process lasts for more than 3ms determined HIC is an effective process, showing Example. (t2-t1) >=3ms.

Composition 5.1.2.2 test equipment

5.1.2.2.1 Test equipment includes an analog head with an acceleration sensor, the impact measurement system, drop height test system is schematically shown in Figure 1 as follows.

Explanation.

1 --- test sample;

2 --- simulated head;

3 --- Impact measurement systems;

4 --- computer;

5 --- acceleration sensor.

1 drop height test system diagram 5.1.2.2.2 simulation head, meet the following requirements.

--- Use material grades for 6061, aluminum alloy T6 heat treatment, processing to a diameter of 160mm ± 5mm, quality 4.6kg ± 0.05kg hemisphere;

--- Three-dimensional acceleration sensor to be mounted on the center of gravity simulation head;

--- Vega when a speed sensor is mounted with its axis coincides with the axis of the head should be simulated, the deviation should be less than 5 °;

--- Simulated head and the acceleration sensor should be closely integrated and seamless, free from vibrations and shocks.

5.1.2.2.3 When using a one-dimensional velocity sensor, there should be a guide rail analog head vertical drop.

5.1.2.2.4 impact measurement system, including the acceleration measurement system, a recording device and a head injury evaluation value (HIC) calculation program.

--- Acceleration measurement system. measurement frequency range of 0.3Hz ~ 1000Hz, the amplitude error should be less than 5%;

--- Recording apparatus, the sampling frequency is not less than 10kHz;

--- According to equation (1) calculated HIC value.

5.1.2.2.5 height measuring apparatus, the accuracy of 1mm.

5.1.2.2.6 release system, the apparatus does not produce any form of torque or force to rotate the first simulation.

5.1.3 Test Accuracy

Simulation head delivery system accuracy should be at least three times the height of the continuous drop in the same test, the resulting HIC deviation should not be large Within ± 5%.

5.1.4 Test Procedure

5.1.4.1 Acceleration - time curve inspection

In the pre-treatment and evaluation, inspection acceleration - time curve without exception, the standard acceleration - time curve shown in Figure 2. If the acceleration - time Abnormal curve between each component should check the instrument device, in particular an acceleration sensor loose.

Explanation.

a --- acceleration;

t --- time in seconds (s);

ta --- start time, in seconds (s);

tb --- End Time, in seconds (s).

Figure 2 standard acceleration - time curve

Select the test points 5.1.4.2

5.1.4.2.1 Test sample point to the edge (or inside of the frame) is not less than 250mm, distance between any two test points is not less than 250mm, 9 were selected test points.

5.1.4.2.2 the test sample is ground when assembled, select at least nine different test points.

--- Assembly center block;

--- Two blocks assembled joint center;

--- Joints assembled the largest junction;

--- Any other point.

5.1.4.2.3 during field testing in the impact zone of the stadium facilities to select the test point, the angle between the horizontal plane and the collision area is not more than 10 °.

5.1.4.3 Laboratory Testing

5.1.4.3.1 General.

a) optionally a test point through the different heights of the impact test, the impact of highly selected HIC value of 1000 ± 100;

b) in section a) of the selected impact height at each test point bump test, select the maximum HIC value of three points as the most Final test points;

Each chosen in c) by) the impact of this Article a selected height of 500mm and down the center of the range of two heights of this section b), select the three test points were four different levels of impact test, to give each impact test and the HIC value Gmax value;

d) draw each test point HIC value and impact of the relationship between the height of the graph, select the HIC value of 1000 in the curve corresponding to the punch Click height (Hc1), see Figure 3; draw Gmax value and impact of the relationship between the height of the graph for each test point, select Gmax value in the curve 200g when the corresponding impact height (Hc2), shown in Figure 4; select Hc1, Hc2 in the critical low drop height. Calculation Results If using tail-law, retained after the decimal point one, in meters.

Explanation.

m --- a measure of the impact;

H --- impact height;

Hc --- critical drop height.

Figure 3 HIC value and impact height versus schematic

Explanation.

m --- a measure of the impact;

H --- impact height;

Hc --- critical drop height.

Figure 4 Gmax and shock value highly schematic curve

5.1.4.3.2 Test loose granular material.

a) selected from the point of not less than 250mm test frame as a test point, select a different height impact test, find the HIC value the impact height between 1000 ± 100, each select two impact within the height range of 500mm and down the center of the height;

b) the distribution of the material in the frame again, to reach the same thickness of the test;

c) Select the lowest value) of this section to determine a height of four, without redistribution of material from the same height Three successive shocks;

d) redistribution of the material in the frame to achieve the same thickness of the test;

e) Select the second impact height (progressively higher) tested, not to redistribute the material, repeated three times. Repeat this process until you have to the desired height of the selected impact test;

f) the same bulk particulate material testing different thickness, before changing the thickness of the test, remove all previously tested material from the frame and replaced with a new material, duplicate section c) of ~ e) entry steps for testing.

5.1.4.4 Field Test

5.1.4.4.1 In addition to the bulk particulate material ground, field test methods and laboratory tests consistent methods, and then record the climatic conditions, such as Temperature and humidity.

5.1.4.4.2 loose granular material ground field test.

a) optionally a test point through the different heights of the impact test, the impact of highly selected HIC value of 1000 ± 100, the impact Select two each impact height within the vertical height of the center of the 500mm range;

b) Each impact height corresponds to a separate test point, the impact of three times in a row;

c) at a distance of 250mm or more other test tap) b of this Article be another level of impact testing. Repeat the above process, finished Into four different height impact tests.

5.2 II class ground

5.2.1 Laboratory test conditions

5.2.1.1 test sample should be (23 ± 2) °C, relative humidity not higher than (55 ± 10)% condition for at least 48h.

5.2.1.2 Point elastic sports venues ground, the size of the test sample was 1.0m × 1.0m.

5.2.1.3 surface elastic sports venues ground, the size of the test sample was 3.5m × 3.5m.

5.2.1.4 hard, smooth, vibration-free concrete floor, its Fr value should meet the requirements of 5.2.3.4.

5.2.2 Test Equipment

5.2.2.1 test equipment, as shown in Figure 5.

Explanation.

1 --- impact hammer rail;

2 --- electromagnet;

3 --- Impact hammer;

4 --- Deck red plate;

5 --- spring;

6 --- guide tube;

7 --- force sensor;

8 --- red bottom bearing plate.

Figure 5 schematic test equipment

5.2.2.2 Impact hammer rail, guided impact hammer free fall.

5.2.2.3 impact hammer, the quality of (20 ± 0.1) kg, with a hard impact surface.

5.2.2.4 Adjustable support leg for the role of point-point elastic sports venues ground support legs and force a minimum distance of 250mm; For Elastic sports venues ground surface, the minimum distance between the support foot and the point of force is 600mm.

5.2.2.5 force measuring device shall be the total mass (3.0 ± 0.3) kg. Cheng punch by a bottom plate, force sensors, springs, and the red disk bearing composition, specific requirements as follows.

--- Bottom bearing plate punch diameter (70.0 ± 0.1) mm, the bottom surface of the spherical radius of 500mm, edge radius of 1mm, the minimum thickness Degree of 10mm;

--- Force sensors, electronic filter critical frequency is 120Hz, to capture the impact of peak duration of about 10ms, the largest measuring the amount of error of 2%;

--- Deck red disc diameter (70.0 ± 0.1) mm, a minimum thickness of 20mm (red disc on the center bearing measurement);

--- Spring diameter (69 ± 1) mm, spring rate is (2000 ± 60) N/mm, in 0.1kN ~ 7.5kN linear range.

5.2.2.6 guide tube, an inner diameter (71.0 ± 0.1) mm.

5.2.3 Test Procedure

5.2.3.1 adjust the measuring device, so that it is perpendicular to the sample. Point elastic sports venues ground, away from the edge of the center of the sample weight is not less than 20cm. Elastic sports venues ground surface, edge distance of the center of the sample weight is not less than 100cm.

5.2.3.2 adjust the height of the impact hammer, so that distance between the bottom and top of the unit load between the (55 ± 0.25) mm. Release impact hammer Records impact during the peak impact force acting on the force measuring device. Reset within 5s of the impact hammer, so that the impact surface is next Restored before impact.

Repeat Step 5.2.3.3 5.2.3.2 twice within (60 ± 10) s intervals, a total of three times the impact test. The second were recorded and third shocks during peak impact, the second and third the average peak impact force as the peak impact force sample Ft value.

5.2.3.4 If the same sample need to do further testing, the new test position and a test position has minimum distance of 100mm.

5.2.4 Formula

5.2.4.1 according to equation (2) calculation of the shock attenuation value R.

× 100 (2)

Where.

R --- shock attenuation values;

The peak impact force Ft --- sample in Newtons (N);

Fr --- peak impact the concrete floor, in Newtons (N), see Appendix A.

5.2.4.2 The results rounded off rounding.

Appendix A

(Normative)

Measurement of reference force Fr A.1 adjust the measurement apparatus, it is perpendicular to the concrete floor.

A.2 adjust the height of the impact hammer, so that distance between the bottom and top of the unit load between the (55 ± 0.25) mm. Release impact hammer, remember Recorded during the impact the peak impact force acting on the force measuring device.

A.3 5.2.3.2 Repeat steps 10 times, a total of 11 impact tests. Record the peak impact from the 2nd to the 11th Impact Process Power, 10 times the average of the peak impact force Fr as a reference value.

A.4 Fr value should be (6.60 ± 0.25) in the kN range.

A.5 every three months should be re-measured Fr value.

references

[1] ASTMF1292-09 playground equipment area floor coverings impact attenuation performance standards [2] BSEN1177:2008 Playground floor coverings shock attenuation properties of the critical drop height test methods [3] BSEN14808:2005 stadium ground floor impact attenuation test method performance [4] ISO 6487:2002 Road vehicles - Impact test Testing Technology Equipment