PSI - Issue 64

Chiara Pepi et al. / Procedia Structural Integrity 64 (2024) 1896–1903 Maria Eleonora Pipistrelli / Structural Integrity Procedia 00 (2019) 000 – 000

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Table 1. Mean values of tensile stress (σ MAX), maximum strain ( ϵ MAX) and elastic modulus (E) calculated for hemp and Spanish broom fibers samples. In first column, tensile properties of rough fibers are listed. The acronym “no - t” in the column heading stands for “no treatment”. Each of the next column collects the tensile properties values calculated at an alkali treatment duration (written in the column heading). C.o.V are written in brackets as percentage values.

Hemp fibers

σ

no-t

0.5 h

1 h

3 h

6 h

18 h

24 h

150.66 (29%) 0.013 (42%) 11772 (25%)

199.03 (40%) 0.015 (47%) 13759 (11%)

112.07 (23%) 0.008 (25%) 13462 (21%)

177.44 (67%) 0.010 (70%) 19252 (35%)

163.83 (56%) 0.011 (50%) 14511 (46%)

190.61 (71%) 0.012 (15%) 15466 (71%)

214.15 (59%) 0.014 (40%) 16951 (49%)

MAX (MPa)

ϵ MAX

Emax (MPa)

Spanish Broom fibers

no-t

0.5 h

1 h

3 h

6 h

18 h

24 h

σ MAX (MPa)

141.50 (28%) 0.028 (8%) 4891 (40%)

111.58 (45%) 0.029 (39%) 3216 (28%)

196.60 (37%) 0.030 (37%) 4895 (30%)

130.32 (63%) 0.020 (46%) 5923 (26%)

209.38 (39%) 0.034 (19%) 5664 (36%)

145.25 (18%) 0.031 (27%) 4455 (12%)

121.32 (36%) 0.028 (24%)

ϵ MAX

Emax (MPa)

4401 (28%)

Table 2 . Mean values of tensile stress (σ MAX ), maximum strain ( ϵ MAX ) and elastic modulus (E) calculated for hemp and Spanish broom fibers samples. In first column, tensile properties of rough fibers are listed. The acronym “no - t” in the column heading stands for “no treatment”. In second column, tensile properties of fibers only coated with graphene (“Graph. In short) are listed. Each of the next column collects the tensile properties values calculated at an alkali+graphene treatment duration. C.o.V are written in brackets as percentage values.

Hemp fibers

σ

no-t

Graph. 262.63 (33%) 0.027 (29%) 14348 (48%) Graph. 144.07 (63%) 0.029 (63%) 4691 (39%)

0.5 h

1 h

3 h

6 h

18 h

24 h

150.66 (29%) 0.013 (42%) 11772 (25%)

182.30 (46%) 0.016 (38%) 13175 (19%)

184.30 (9%) 0.014 (28%) 11899 (22%)

194.26 (21%) 0.021 (17%) 11336 (17%)

166.23 (41%) 0.012 (33%) 15623 (15%)

219.35 (67%) 0.024 (15%) 8868 (66%)

82.33 (36%) 0.016 (48%) 6741 (37%)

MAX (MPa)

ϵ MAX

E (MPa)

Spanish Broom fibers

no-t

0.5 h

1 h

3 h

6 h

18 h

24 h

σ MAX (MPa)

141.50 (28%) 0.028 (8%) 4891 (40%)

374.90 (21%) 0.039 (18%) 10313 (5%)

180.02 (36%) 0.041 (36%) 4436 (26%)

264.66 (58%) 0.032 (25%) 6653 (37%)

245.25 (10%) 0.037 (50%) 6854 (51%)

325.62 (34%) 0.037 (36%) 8483 (14%)

358.37 (21%) 0.039 (35%) 9616 (41%)

ϵ MAX

E (MPa)