Analysis of the Variation of Friction Coefficient of Sandstone Joint in Sliding

Table 1

Wear mass (m), total wear area rate (A_r), and surface roughness of wear zone (Sa_ij) with cycles.

Number of cycles	m (mg)	Ar (%)	Saij (μm)
			Sa1j	Sa2j	Sa3j	Sa4j	Sa5j	Sa6j	Sa7j	Sa8j	Sa9j	Sa10j
1	20.2	10.89	69.88
2	15.3	13.56	41.37	57.45
3	17.3	16.37	37.62	39.88	62.76
4	16.9	19.09	33.96	35.64	38.84	46.73
5	16.4	21.51	31.84	32.39	35.75	37.52	63.89
6	15.2	23.40	30.64	31.18	33.62	34.47	45.12	55.74
7	15.8	25.08	30.18	30.43	31.26	31.93	38.53	40.53	59.94
8	15.2	26.54	29.87	30.65	30.88	30.45	32.49	36.28	41.08	65.38
9	14.1	28.17	30.24	30.26	30.19	30.21	31.34	32.37	35.33	38.66	56.63
10	15.3	29.54	30.17	30.15	30.44	30.39	30.82	31.03	31.29	33.59	37.42	60.42