Understanding Friction and Wear Behaviours of Smooth Resilient Surfaces: Application for Pedestrian Fall Safety Improvements
Table 1
Measurement results of the surface roughness parameters for the PMMA specimens before (BDFT) and after the dynamic friction tests (ADFT).
Test condition and changing rate
PMMA specimen
Surface roughness parameter (µm)
Ra1
Rq2
Rtm3
Rpm4
Rvm5
Δa6
Rsk7
Rkr8
BDFT
PMMA1
2.330
3.121
16.817
6.483
−7.492
0.072
−0.432
1.002
PMMA2
3.769
4.756
22.316
8.968
−9.483
0.096
−0.256
−0.011
PMMA3
4.213
5.212
23.299
8.930
−10.968
0.102
−0.202
−0.242
PMMA4
4.837
6.082
27.800
11.745
−11.175
0.122
−0.046
0.180
ADFT
PMMA1
1.477
1.973
15.860
4.882
−3.645
0.041
0.283
1.624
PMMA2
1.895
2.543
16.829
5.640
−4.303
0.059
0.295
2.804
PMMA3
2.190
3.033
20.307
6.204
−5.236
0.069
0.280
2.569
PMMA4
2.933
3.807
23.293
6.438
−6.037
0.078
0.248
1.344
Changing rate of surface roughness parameters (%)
PMMA1
36.61
36.78
5.69
24.7
51.35
43.06
−0.2349 (BDFT) 0.22711(ADFT)
0.23210 (BDFT) 2.08512 (ADFT)
PMMA2
49.72
46.53
24.59
37.11
54.62
38.54
PMMA3
48.02
41.81
12.84
30.53
52.26
32.35
PMMA4
39.36
37.41
16.21
45.19
45.98
36.07
Avg.
43.43
40.63
14.83
34.38
51.05
37.51
Std. dev.
6.42
4.52
7.85
8.81
3.65
4.49
1: centre-line average roughness; 2: root-mean-square roughness; 3: maximum mean peak-to-valley height; 4: maximum mean peak height; 5: maximum mean depth height; 6. Δa: average slope angle; 7: skewness; 8: kurtosis; 9: average of the initial surfaces’ skewness; 10: average of the rubbed surfaces’ skewness; 11: average of the initial surfaces’ kurtosis; 12: average of the rubbed surfaces’ kurtosis.
