Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions
Hybrid continuous-discontinuous sheet molding compound (SMC) composites are considered suitable candidates for structural automotive applications, due to their high mass-specific mechanical properties combined with high geometrical flexibility and low costs. Since structural automotive parts are sub...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-07-01
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| Series: | Composites Part C: Open Access |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666682022000329 |
| _version_ | 1818109826331312128 |
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| author | M. Bartkowiak M. Kizak W.V. Liebig K.A. Weidenmann |
| author_facet | M. Bartkowiak M. Kizak W.V. Liebig K.A. Weidenmann |
| author_sort | M. Bartkowiak |
| collection | DOAJ |
| description | Hybrid continuous-discontinuous sheet molding compound (SMC) composites are considered suitable candidates for structural automotive applications, due to their high mass-specific mechanical properties combined with high geometrical flexibility and low costs. Since structural automotive parts are subject to repeated loading, profound knowledge of their fatigue behavior is required. This paper presents an experimental study on the bending fatigue behavior of hybrid SMC with discontinuous glass fibers in the core and unidirectional continuous carbon fibers in the face layers. Effects of hybridization on the S-N behavior and stiffness degradation have been analyzed in constant amplitude fatigue tests under 3-point bending load at different temperatures and frequencies. Microscopic investigations on polished specimen edges were used to study the damage behavior. The ultimate flexural strength at quasi-static (UFSS) and fatigue strain rate (UFSF) of the hybrid composite was 54 % and 59 % higher than that of discontinuous SMC, respectively. In contrast, the flexural fatigue strength at 2.6⋅106 cycles increased by 258 %. The relative stiffness degradation of the hybrid composites was smaller during most of their fatigue lives due to the continuous carbon fiber reinforcement. The carbon fiber ply on the compression loaded side was the first ply to fail. Fatigue stress significantly decreased at 80 °C due to early kinking of the continuous carbon fiber-reinforced ply on the compression loaded side. Variation of frequency had no significant effect on the fatigue behavior of both discontinuous and continuous-discontinuous SMC. |
| first_indexed | 2024-12-11T02:37:25Z |
| format | Article |
| id | doaj.art-c72d93cde7c1466b821b78ad052b8330 |
| institution | Directory Open Access Journal |
| issn | 2666-6820 |
| language | English |
| last_indexed | 2024-12-11T02:37:25Z |
| publishDate | 2022-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Composites Part C: Open Access |
| spelling | doaj.art-c72d93cde7c1466b821b78ad052b83302022-12-22T01:23:42ZengElsevierComposites Part C: Open Access2666-68202022-07-018100265Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditionsM. Bartkowiak0M. Kizak1W.V. Liebig2K.A. Weidenmann3Karlsruhe Institute of Technology, Institute for Applied Materials – Material Science and Engineering, Engelbert-Arnold-Str. 4, 76131, Karlsruhe, Germany; Corresponding author.Karlsruhe Institute of Technology, Institute for Applied Materials – Material Science and Engineering, Engelbert-Arnold-Str. 4, 76131, Karlsruhe, GermanyKarlsruhe Institute of Technology, Institute for Applied Materials – Material Science and Engineering, Engelbert-Arnold-Str. 4, 76131, Karlsruhe, GermanyUniversity of Augsburg, Institute for Materials Resource Management, Am Technologiezentrum 8, 86159, Augsburg, GermanyHybrid continuous-discontinuous sheet molding compound (SMC) composites are considered suitable candidates for structural automotive applications, due to their high mass-specific mechanical properties combined with high geometrical flexibility and low costs. Since structural automotive parts are subject to repeated loading, profound knowledge of their fatigue behavior is required. This paper presents an experimental study on the bending fatigue behavior of hybrid SMC with discontinuous glass fibers in the core and unidirectional continuous carbon fibers in the face layers. Effects of hybridization on the S-N behavior and stiffness degradation have been analyzed in constant amplitude fatigue tests under 3-point bending load at different temperatures and frequencies. Microscopic investigations on polished specimen edges were used to study the damage behavior. The ultimate flexural strength at quasi-static (UFSS) and fatigue strain rate (UFSF) of the hybrid composite was 54 % and 59 % higher than that of discontinuous SMC, respectively. In contrast, the flexural fatigue strength at 2.6⋅106 cycles increased by 258 %. The relative stiffness degradation of the hybrid composites was smaller during most of their fatigue lives due to the continuous carbon fiber reinforcement. The carbon fiber ply on the compression loaded side was the first ply to fail. Fatigue stress significantly decreased at 80 °C due to early kinking of the continuous carbon fiber-reinforced ply on the compression loaded side. Variation of frequency had no significant effect on the fatigue behavior of both discontinuous and continuous-discontinuous SMC.http://www.sciencedirect.com/science/article/pii/S2666682022000329Hybrid compositesFatigueSheet Molding CompoundContinuous-discontinuous reinforcementDamageEffects of Hybridization |
| spellingShingle | M. Bartkowiak M. Kizak W.V. Liebig K.A. Weidenmann Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions Composites Part C: Open Access Hybrid composites Fatigue Sheet Molding Compound Continuous-discontinuous reinforcement Damage Effects of Hybridization |
| title | Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions |
| title_full | Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions |
| title_fullStr | Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions |
| title_full_unstemmed | Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions |
| title_short | Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions |
| title_sort | fatigue behavior of hybrid continuous discontinuous fiber reinforced sheet molding compound composites under application related loading conditions |
| topic | Hybrid composites Fatigue Sheet Molding Compound Continuous-discontinuous reinforcement Damage Effects of Hybridization |
| url | http://www.sciencedirect.com/science/article/pii/S2666682022000329 |
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