PSI - Issue 54

Isyna Izzal Muna et al. / Procedia Structural Integrity 54 (2024) 437–445 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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4. Results In this study, the mechanical response of printed CFRP samples after thermal treatment and without thermal treatment has been simulated with FEM software at microscale and macroscale. Figure 5 shows the stress distribution of a unit cell after tensile testing, after thermal exposure, and after thermal-tensile loading. It can be observed that in Figure 5a, when only tensile loading is applied the stress is very much concentrated in the fiber cell than matrix due to the stiffness behavior of the fiber. When thermal loading applied to unit cell gives the different magnitudes of stress distribution in the matrix and fiber cell as shown in Figure 5b, this is due to the elasto-plasticity behavior and higher thermal expansion of the polymer and carbon fiber. In the Figure 5c, with the thermal and tensile loading the stress distribution in the matrix and fiber are more varied due to the anisotropy behavior of CFRP unit cell. a)

b)

c)

Fig. 5. (a) after tensile loading without thermal treatment; (b) after thermal loading; (c) after tensile loading with thermal treatment

The tensile strength and Young’s modulus of each sample group (intact, HS -A, HS-B) was compared between experimental values with the values obtained from microscale and macroscale simulation as shown in Table 2 and Table 3, respectively. It can be seen that the strength and modulus values from microscale gives less accurate prediction than macroscale simulation compared to the experimental values after the thermal loading. ‹—Žƒ–‹‘ ƒ–  ‹‘ †”‡‘Ž‹ ‘‰† ƒ‡ Ž„ ”ƒ‹ † ‰ „‡‡ • ‹‹’—”Ž‘ƒ –˜‹‡‘† ™ƒ –‹ –Š ‡Š•‘‘• ‘ƒ‰Ž‡‡ –‹‘œ ƒ ‘– ‹„‘–ƒ ‹–‡ Š‘”‹ “‡ —†‡‡ ƒ• ‹”†‡ †– Š”‡‡ •—ƒŽ – •”Ǥ ‘ • ƒ Ž ‡  ‘ † ‡ Ž ƒ  „ ‡ ‹  ’ ” ‘ ˜ ‡ † „ › Since the homogenization technique is not applied in this microscale simulation, therefore it is planned in our next work to use homogenization technique in order to compute the effective properties of the CFRP composites. A mesoscale model at cross-ply laminate can be used in case of multidirectional layers of CFRP samples for simplifying its structural arrangement via local homogenization method. The macroscale model of UD CFRP composites will be then established by extending the mesoscale model. ‘”‡‘˜‡”ǡ ‘‡ • ƒŽ‡ †‘™ ˆ”‘ ‹ ”‘• ƒŽ‡ ƒ– ‘Ž‡ —Žƒ” Ž‡˜‡Ž ‹‰Š– ‡‡† –‘ „‡ ’‡”ˆ‘”‡† –‘ ‘†‡Ž –Š‡ —”‹‰ ’”‘ ‡•• ‘ˆ –Š‡ ƒ–”‹š ‘’‘‡–Ǥ The mechanical properties from „‘–Š ‹ ”‘• ƒŽ‡ ƒ† ƒ ”‘• ƒŽ‡ ‘˜‡”‡•–‹ƒ–‡ –Š‡ ‡š’‡”‹‡–ƒŽ ”‡•—Ž–Ǥ – ‹• ƒŽ ‘•™• —‡” ‡ †‡ – ŠŠƒƒ– –‹ Š ƒ‡ Ž † ’‡”ˆ‘‡’ –‡•” –‹ ‹‡ • ˜ ƒ Ž — ‡• •ƒ ‹ ’ –ŽŠ‡ ‡• ”‡‡š•’—‡Ž”–‹‡† ‡ˆ ” ‘– Ǥ Š– Š‡ ‡ ‡ ˆ ˆƒ‹ – ‹—‡”‡ ‘› ˆ ƒ  ƒ Ž › •’‹ •” ‹ ˆ”–‘‹ ‰ „‘ ‡– Š– Š •‘ †ƒ Žƒ‡ˆ•ˆ ‡” ‡–˜‹ ‡ ƒ‰ Ž ––ŠŠ‡ƒ – • ‹ œ‹ ‡” ‹‘• – Šƒ‡Ž ‡ ’ ” ‡ ’ ” •‘‹ ‡—• •Ž ƒ‹ – ‹‰‘ ™ ‰Š‹‡˜”‡‡• ‹ – ‘ ƒ ’ ”—‡– †ƒ –—‹ ‘‡ ƒ• ‘Ž •Ž ˜ƒ‹˜‹‰ ‰– ‹ „ ‡‡ ƒ†——•”‡‹  ‘‰ˆ –‡Šƒ‡• ‹’‡””‘ ‡‘•†•‡‹ Ž ‹‰Ǥ ‰ • – ƒ ‰ ‡ ƒ  † •  ƒ Ž Ž ‡ ”  ‘ † ‡ Ž