Integration of Networks of Sensors and Electronics for Structural Health Monitoring of Composite Materials

Table 4

Material without and with embedded inclusions: tensile strength and acoustic behavior.

[0]𝑛	Number of samples	𝜎FAE Average (MPa)	DS∗∗	CV %∗∗	Strength Average (MPa)	DS	CV %
Blank samples	5	319.6	20.07	6.15	1729.4	40	2.33
Samples with integrated device	5	89.7	22.18	24.7	1685	39.9	2.37
[(±45)5]s	Results	^∗𝜎tE/𝜎tB	97.42 %		𝜎FAE-B/𝜎FAE-E	3.56
	Number of samples	𝜎FAE Average (MPa)	DS∗∗	CV %∗∗	Strength Average (MPa)	DS	CV %
Blank samples	3	34.46	8.05	23.37	220	5.19	2.36
Samples with integrated device	3	12.53	1.61	12.89	229	5.03	2.19
	Results	^∗𝜎tE/𝜎tB	36.37%		𝜎FAE-B/𝜎FAE-E	2.9

^∗𝜎_tE: tensile strength of the material with integrated inclusion; 𝜎_tB: tensile strength of blank samples; 𝜎_FAE-B: stress at which the acoustic events start in blank samples; 𝜎_FAE-E: stress at which the events begin in sample with embedded device.
∗∗DS: Standard Deviation; CV: coefficient of variation; definitions according to ASTM 3039M.