Fig. 1.
Martindale abrasion tester
Tab. 1.
Average results of Tensile test for Kevlar and Carbon fabric on different conditions
| Average Results in Dry Conditions | |||
|---|---|---|---|
| Fabric Code | Thickness (mm) | Tensile strength (MPa) | Fmax (N) |
| K1 (Warp) | 0.24 | 548.21 | 3289.25 |
| K2 (Weft) | 0.24 | 512.19 | 3073.14 |
| C1 (Warp) | 0.28 | 340.33 | 2382.33 |
| C2 (Weft) | 0.28 | 149.38 | 1045.69 |
| Average Results with Water Conditions | |||
| K3 (Warp) | 0.24 | 546.44 | 3278.64 |
| K4 (Weft) | 0.24 | 510.57 | 3063.43 |
| C3 (Warp) | 0.28 | 359.68 | 2517.74 |
| C4 (Weft) | 0.28 | 29.78 | 208.48 |
| Average Results with Sweat Conditions | |||
| K5 (Warp) | 0.24 | 527.45 | 3164.71 |
| K6 (Weft) | 0.24 | 507.50 | 3045.01 |
| C5 (Warp) | 0.28 | 326.22 | 2283.51 |
| C6 (Weft) | 0.28 | 116.14 | 812.95 |
Fig. 2.
Kevlar and Carbon fabrics samples after cutting in 80mm diameter from fabrics and in holders before test
Fig. 3.
Average results of Tensile strength in dry and wet cases for: a) Kevlar fabric, b) Carbon
Tab. 2.
Average results of Tensile test for Kevlar and Carbon fabric on different conditions
| for (Kevlar/Epoxy, Carbon/Epoxy, and K-C hybrid/Epoxy) in warp and weft directions | |||||
|---|---|---|---|---|---|
| Code | Thickness (mm) | Max Strain % | Tensile strength (MPa) | Fmax (kN) | E-Mod (GPa) |
| K (warp) | 2.25 | 4.03 | 358.63 | 19.72 | 8.39 |
| K (weft) | 2.13 | 4.56 | 341.28 | 18.20 | 6.77 |
| C (warp) | 2.30 | 2.09 | 391.85 | 23.13 | 21.64 |
| C (weft) | 2.37 | 1.65 | 333.68 | 19.13 | 22.20 |
| KC (warp) | 2.17 | 2.31 | 372.04 | 20.06 | 16.07 |
| KC (weft) | 2.30 | 1.84 | 238.97 | 13.73 | 11.96 |
| for both directions (warp & weft) for each composite (Kevlar/Epoxy, Carbon/Epoxy, and K-C hybrid/Epoxy) | |||||
| K | 2.19 | 4.30 | 349.95 | 18.96 | 7.58 |
| C | 2.33 | 1.87 | 362.77 | 21.13 | 21.92 |
| KC | 2.23 | 2.08 | 305.51 | 16.89 | 14.01 |
Fig. 4.
Average mechanical properties for (Kevlar/Epoxy, Carbon/Epoxy, and K-C hybrid/Epoxy) in warp and weft directions for; a) Tensile strength, b) Young’s modulus
Fig. 5.
Stress-Strain curve composites in warp and weft directions of: a) Kevlar/epoxy, b) Carbon/epoxy and c) Kevlar – Carbon/epoxy
Fig. 6.
The failures of the composite; a) (Kevlar/Epoxy, Carbon/Epoxy, and K-C hybrid/Epoxy), b) Kevlar fabric against sandpapers, c) Carbon fabric against sandpapers in warp and weft directions
Tab. 3.
Average results for Abrasion test samples in different conditions
| in Dry case for Kevlar and Carbon fabrics | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cycles | P500 | P1000 | P1200 | |||||||||
| Fabric code | Mass before (g) | Mass after (g) | % | Fabric code | Mass before (g) | Mass af- | % | Fabric code | Mass before (g) | Mass after (g) | % | |
| 25 | S1 | 1 | 0.997 | 0.23 | S4 | 1 | 0.998 | 0.16 | S7 | 1 | 0.999 | 0.03 |
| 50 | S2 | 1 | 0.996 | 0.36 | S5 | 1 | 0.997 | 0.26 | S8 | 1 | 0.998 | 0.13 |
| 75 | S3 | 1 | 0.995 | 0.43 | S6 | 1 | 0.996 | 0.33 | S9 | 1 | 0.997 | 0.23 |
| 25 | C1 | 1 | 0.996 | 0.33 | C4 | 1 | 0.998 | 0.20 | C7 | 1 | 0.998 | 0.16 |
| 50 | C2 | 1 | 0.995 | 0.50 | C5 | 1 | 0.9970 | 0.30 | C8 | 1 | 0.9980 | 0.20 |
| 75 | C3 | 1 | 0.994 | 0.56 | C6 | 1 | 0.9963 | 0.36 | C9 | 1 | 0.9967 | 0.33 |
| with pure water case for Kevlar and Carbon fabrics | ||||||||||||
| 25 | S10 | 1.829 | 1.82 | 0.60 | S13 | 1.83 | 1.82 | 0.38 | S16 | 1.828 | 1.826 | 0.1094 |
| 50 | S11 | 1.829 | 1.82 | 0.77 | S14 | 1.83 | 1.82 | 0.55 | S17 | 1.828 | 1.824 | 0.22 |
| 75 | S12 | 1.828 | 1.81 | 0.88 | S15 | 1.83 | 1.82 | 0.66 | S18 | 1.828 | 1.821 | 0.38 |
| 25 | C10 | 1.682 | 1.67 | 0.77 | C13 | 1.68 | 1.67 | 0.54 | C16 | 1.682 | 1.679 | 0.18 |
| 50 | C11 | 1.682 | 1.67 | 0.95 | C14 | 1.68 | 1.67 | 0.71 | C17 | 1.682 | 1.675 | 0.42 |
| 75 | C12 | 1.682 | 1.66 | 1.07 | C15 | 1.68 | 1.67 | 0.89 | C18 | 1.682 | 1.672 | 0.59 |
| sweat simulation case for Kevlar and Carbon fabrics | ||||||||||||
| 25 | S19 | 1.841 | 1.829 | 0.6518 | S22 | 1.841 | 1.833 | 0.4346 | S25 | 1.841 | 1.837 | 0.2173 |
| 50 | S20 | 1.839 | 1.824 | 0.8157 | S23 | 1.841 | 1.829 | 0.6518 | S26 | 1.840 | 1.834 | 0.3261 |
| 75 | S21 | 1.841 | 1.823 | 0.9777 | S24 | 1.841 | 1.827 | 0.7605 | S27 | 1.841 | 1.832 | 0.4889 |
| 25 | C19 | 1.698 | 1.683 | 0.8834 | C22 | 1.698 | 1.688 | 0.5890 | C25 | 1.698 | 1.693 | 0.2945 |
| 50 | C20 | 1.698 | 1.681 | 1.0012 | C23 | 1.697 | 1.684 | 0.7661 | C26 | 1.698 | 1.689 | 0.5300 |
| 75 | C21 | 1.698 | 1.679 | 1.1190 | C24 | 1.698 | 1.682 | 0.9423 | C27 | 1.698 | 1.686 | 0.7067 |
Fig. 7.
The failure modes before and after 75 abrasion cycles for a) Kevlar dry, b) Kevlar pure water, c) Kevlar sweat, b) carbon dry, e) carbon pure water, f) carbon sweat