Ultrasonic Guided Waves-Based Monitoring of Rail Head: Laboratory and Field Tests

Table 1

Laboratory test site layout.

Location #		Distance (mm)	Description	Head area reduction	Test 1 center head pair	Test 1 gage side pair	Test 2 center head pair	Test 2 gage side pair	Test 3 center head pair	Test 3 gage side pair
Rail 1	1	0	Joint: start of test zone		1–4	1–3	1–3	1–2	1–3	1
	2	127	Surface transverse notch	1%	5–6	4–5	4	3–4	4–5	2–4
			No defect		7–11	6–11	5–10	5–10	6–11	5–1
	3	920	Start longitudinal notch		12	12	11	11	12	12
	4	968	End longitudinal notch		15	15	15	14	15	15
			No defect		16–17	16–18	16	15–17	16–17	16–18
	5	1428	Surface transverse notch	16%	18–21	19–21	17–20	18–20	18–21	19–21
			No defect		22–24	22–25	21–24	21–24	22–25	22–25
	6	2060	Surface transverse notch	5%	25–29	26–29	25–28	25–28	26–29	26–29
			No defect		—	30	—	29	—	30
	7	2432	Joint		30–34	31–33	29–33	30–32	31–34	31–33
Rail 2			No defect		35–38	34–38	34–36	33–37	35–37	34–38
	8	3073	Internal defect	8%	39–41	39–41	37–41	38–40	38–41	39–41
			No defect		42–46	42–46	42–46	41–46	42–46	42–47
	9	3789	Joint		47–50	47–50	47–49	47–49	47–50	48–50
Rail 3			No defect		51–54	51–54	50–52	50–53	51–54	51–55
	10	4445	Internal defect	23%	55–58	55–57	53–56	54–56	55–59	56–58
			No defect		59–61	58–61	57–59	57–59	60–61	59–62
	11	5013	Joint		62–65	62–65	60–63	60–62	62–66	63–65
Rail 4			No defect		66–69	66–70	64–66	63–67	67–68	66–68
	12	5657	Surface oblique notch	7%	70–73	71–73	67–70	68–69	69–72	69–71
			No defect		74	74	—	70–71	—	72–73
	13	6010	Surface transverse notch	20%	75–78	75–78	71–74	72–74	73–77	75–77