# Investigation of the Deformation Behaviour and Resulting Ply Thicknesses of Multilayered Fibre–Metal Laminates

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^{2}

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## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

^{®}CFR-TP PA6 CF60-01, Dallas, TX, USA) and Al-5754 aluminium alloy sheets were used in the experiments. Table 1 provides the chemical composition of the Al-5754 used in this study. The plies were bonded to each other using an adhesive layer based on polyolefin, i.e., Cox 391 (nolax AG, Sempach, Switzerland) with a thickness of 0.1 mm. The two lay-ups of multilayered FML used in this study are shown in Figure 1 and their details are given in Table 2. Figure 2 shows the manufacturing steps, including schematic illustrations of the adhesion and forming processes. Due to the different thermal conductivity of the individual layers, laminates were equipped with internal thermocouples in a preliminary study in order to determine a correlation between the external temperature profiles and the temperatures occurring in the laminate for all manufacturing steps.

## 3. Finite-Element Analysis

## 4. Results and Discussion

^{2}from 0.87 to 0.97 when a temperature-dependent friction coefficient is implemented.

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

## References

- Rubio, E.M.; Blanco, D.; Marín, M.M.; Carou, D. Analysis of the latest trends in hybrid components of lightweight materials for structural uses. Procedia Manuf.
**2019**, 41, 1047–1054. [Google Scholar] [CrossRef] - Khosravani, M.R.; Anders, D.; Weinberg, K. Influence of strain rate on fracture behavior of sandwich composite T-joints. Eur. J. Mech. A Solids
**2019**, 78. [Google Scholar] [CrossRef] - Kuhtz, M.; Buschner, N.; Henseler, T.; Hornig, A.; Klaerner, M.; Ullmann, M.; Jäger, H.; Kroll, L.; Kawalla, R. An experimental study on the bending response of multi-layered fibre-metal-laminates. J. Compos. Mater.
**2019**, 53, 2579–2591. [Google Scholar] [CrossRef] [Green Version] - Trautmann, M.; Mrzljak, S.; Walther, F.; Wagner, G. Mechanical Properties of Thermoplastic-Based Hybrid Laminates with Regard to Layer Structure and Metal Volume Content. Metals
**2020**, 10, 1430. [Google Scholar] [CrossRef] - Venkatesan, C.; Velu, R.; Vaheed, N.; Raspall, F.; Tay, T.-E.; Silva, A. Effect of process parameters on polyamide-6 carbon fibre prepreg laminated by IR-assisted automated fibe placement. Int. J. Adv. Manuf. Technol.
**2020**, 108, 1275–1284. [Google Scholar] [CrossRef] - Ding, Z.; Wang, H.; Luo, J.; Li, N. A review on forming technologies of fibre metal laminates. Int. J. Lightweight Mater. Manuf.
**2021**, 4, 110–126. [Google Scholar] [CrossRef] - Werner, H.O.; Dörr, D.; Henning, F.; Kärger, L. Numerical Modeling of a Hybrid Forming Process for Three-Dimensionally Curved Fiber-Metal Laminates; AIP Conference Proceedings: Vitoria-Gasteiz, Spain, 2019. [Google Scholar] [CrossRef]
- Behrens, B.A.; Vucetic, M.; Neumann, A.; Osiecki, T.; Grbic, N. Experimental Test and FEA of a Sheet Metal Forming Process of Composite Material and Steel Foil in Sandwich Design Using LS-DYNA. Key Eng. Mater.
**2015**, 651–653, 439–445. [Google Scholar] [CrossRef] - Blala, H.; Lang, L.; Sherkatghanad, E.; Li, L. An Investigation into Process Parameters Effect on the Formability of GLARE Materials Using Stamp Forming. Appl. Compos. Mater.
**2019**, 26, 1423–1436. [Google Scholar] [CrossRef] - Kalyanasundaram, S.; DharMalingam, S.; Venkatesan, S. Forming Analysis of Composite and Fibre-metal Laminate Systems. In Proceedings of the ECCM15-15th European Conference on Composite Materials, Venice, Italy, 24–28 June 2012. [Google Scholar]
- Dou, X.; Malingam, S.D.; Nam, J.; Kalyanasundaram, S. Finite Element Modeling of Stamp Forming Process on Thermoplastic-Based Fiber Metal Laminates at Elevated Temperatures. World J. Eng. Tech.
**2015**, 3, 253. [Google Scholar] [CrossRef] [Green Version] - Sexton, A.; Venkatesan, S.; Cantwell, W.; Kalyanasundaram, S. Experimental and numerical characterisation of the out-of-plane stretch forming of a fibre metal laminate based on a self-reinforced polypropylene composite. In Proceedings of the ECCM15-15th European Conference on Composite Materials, Venice, Italy, 24–28 June 2012. [Google Scholar]
- Hahn, M.; Khalifa, N.B.; Shabaninejad, A. Prediction of Process Forces in Fiber Metal Laminate Stamping. J. Manuf. Sci. Eng.
**2018**, 140. [Google Scholar] [CrossRef] - Saadatfard, A.; Gerdooei, M.; Jalali Aghchai, A. Drawing potential of fiber metal laminates in hydromechanical forming: A numerical and experimental study. J. Sandw. Struct. Mater.
**2020**, 22, 1386–1403. [Google Scholar] [CrossRef] - Wollmann, T.; Hahn, M.; Wiedemann, S.; Zeiser, A.; Jaschinski, J.; Modler, N.; Ben Khalifa, N.; Meißen, F.; Paul, C. Thermoplastic fibre metal laminates: Stiffness properties and forming behaviour by means of deep drawing. Arch. Civ. Mech. Eng.
**2018**, 18, 442–450. [Google Scholar] [CrossRef] - DharMalingam, S.; Compston, P.; Kalyanasundaram, S. Process Variables Optimisation of Polypropylene Based Fibre-Metal Laminates Forming Using Finite Element Analysis. Key Eng. Mater.
**2009**, 410–411, 263–269. [Google Scholar] [CrossRef] - Mosse, L.; Compston, P.; Cantwell, W.J.; Cardew-Hall, M.; Kalyanasundaram, S. The development of a finite element model for simulating the stamp forming of fibre–metal laminates. Compos. Struct.
**2006**, 75, 298–304. [Google Scholar] [CrossRef] - Rajabi, A.; Kadkhodayan, M. An Investigation into the Deep Drawing of Fiber-metal Laminates based on Glass Fiber Reinforced Polypropylene. Int. J. Eng.
**2014**, 27, 349–358. [Google Scholar] - Yang, H.; Xiao, R.; Yang, Z.; Lei, D. Experimental characterization and finite element modeling the deformation behavior of rubbers with geometry defects. Polym. Test.
**2019**, 80, 106111. [Google Scholar] [CrossRef] - Chen, Z.; Song, X.; Liu, S. Thermo-mechanical characterization of copper filled and polymer filled tsvs considering nonlinear material behaviors. In Proceedings of the 59th Electronic Components and Technology Conference, San Diego, CA, USA, 26–29 May 2009; pp. 1374–1380. [Google Scholar] [CrossRef]
- Bergman, T.L.; Lavine, A.S.; Incropera, F.P. Fundamentals of Heat and Mass Transfer, 8th ed.; John Wiley and Sons Ltd.: Chichester, UK, 2011. [Google Scholar]
- Chapman, A.J. Fundamentals of Heat Transfer; Macmillan: New York, NY, USA, 1987. [Google Scholar]
- Razali, M.K.; Irani, M.; Joun, M.S. Practical Acquisition and Application of Flow Stresses Emphasizing on Prediction Accuracy for Bearing Steel, STB2. Key Eng. Mater.
**2020**, 830, 101–106. [Google Scholar] [CrossRef] - Razali, M.K.; Irani, M.; Joun, M. General modeling of flow stress curves of alloys at elevated temperatures using bi-linearly interpolated or closed-form functions for material parameters. J. Mater. Res. Tech.
**2019**, 8, 2710–2720. [Google Scholar] [CrossRef] - Wang, Z. Effects of temperature and strain rate on the tensile behavior of short fiber reinforced polyamide-6. Polym. Compos.
**2002**, 23, 858–871. [Google Scholar] [CrossRef] - Myshkin, N.K.; Petrokovets, M.I.; Kovalev, A.V. Tribology of polymers: Adhesion, friction, wear, and mass-transfer. Tribol. Int.
**2005**, 38, 910–921. [Google Scholar] [CrossRef]

**Figure 4.**(

**a**) Micrograph of lay-up L2 and (

**b**) finite-element model and meshing system (dimensions in mm).

**Figure 6.**Influence of the Coulomb coefficient factor on inter-ply slippage. (

**a**) µ = 0.01, (

**b**) µ = 0.1, and (

**c**) µ = 0.2.

**Figure 7.**Influence of the inter-ply Coulomb coefficient on the α angle. (

**a**) µ = 0.01, (

**b**) µ = 0.1, and (

**c**) µ = 0.2.

**Figure 9.**Delamination at the metal–polymer interface. (

**a**) Final product with L1 and (

**b**) semi-deformed profile with L2 at the forming load of 10 kN.

**Figure 10.**Predicted delamination at the metal–polymer interface in a semi-deformed profile with L2 in the middle forming stages.

**Figure 12.**Measured and predicted thickness of CFRP plies at the head radius. (

**a**) Constant friction coefficient. (

**b**) Temperature-dependent friction coefficient.

Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Al |
---|---|---|---|---|---|---|---|---|

0.4 | 0.4 | 0.1 | 0.5 | 3.0 | 0.3 | 0.2 | 0.15 | Balance |

Lay-Up | Dimensions (mm) | Mesh Size of M Plies in the Simulations (mm) |
---|---|---|

L1 [M/C]s | [1.0/0.5]s | 0.25 |

L2 [(M/C)2]s | [(1.0/0.5)2]s | 0.25 |

Temperature (°C) | Thermal Conductivity (J/kg·°C) | Heat Capacity (W/m·°C) | Elastic Modulus (GPa) |
---|---|---|---|

50 | 140.0 | 0.93 | 69.0 |

100 | 145.0 | 0.96 | 68.0 |

150 | 150.0 | 0.975 | 65.0 |

200 | 154.0 | 0.99 | 63.0 |

250 | 157.0 | 1.00 | 60.0 |

$\mathit{A}$ | ${\mathit{m}}_{1}$ | ${\mathit{m}}_{2}$ | ${\mathit{m}}_{3}$ | ${\mathit{m}}_{4}$ |
---|---|---|---|---|

335.92 | −0.00167 | 0.10085 | −0.00058 | 0.0 |

Strain Rate (s^{–1}) | Temperature (°C) | $\mathbf{Stress}\mathbf{Coefficient}({\mathit{\sigma}}^{*};\mathbf{MPa})$ |
---|---|---|

$8.5\times {10}^{-4}$ | 21.5 | 118.8 |

$8.5\times {10}^{-3}$ | 132.0 | |

$8.5\times {10}^{-2}$ | 138.6 | |

$8.5\times {10}^{-4}$ | 50 | 87.1 |

$8.5\times {10}^{-3}$ | 94.3 | |

$8.5\times {10}^{-2}$ | 101.6 | |

$8.5\times {10}^{-4}$ | 75 | 70.6 |

$8.5\times {10}^{-3}$ | 77.2 | |

$8.5\times {10}^{-2}$ | 79.6 | |

$8.5\times {10}^{-4}$ | 100 | 58.7 |

$8.5\times {10}^{-3}$ | 62.9 | |

$8.5\times {10}^{-2}$ | 64.8 | |

$8.5\times {10}^{-4}$ | 150 | 16.6 |

$8.5\times {10}^{-3}$ | 14.9 | |

$8.5\times {10}^{-2}$ | 13.1 |

**Table 6.**Measured and predicted thickness of the deformed multilayered FML (constant friction coefficient).

Lay-Up | Ply | Thickness at P1 (micron) | Thickness at P2 (micron) | Thickness at P3 (micron) | ||||||
---|---|---|---|---|---|---|---|---|---|---|

Measured | Predicted | Error (%) | Measured | Predicted | Error (%) | Measured | Predicted | Error (%) | ||

L1 | CFRP | 822 | 971 | 18.1 | 832 | 955 | 14.8 | 881 | 970 | 10.0 |

CFRP1 | 430 | 454 | 5.5 | 440 | 445 | 1.1 | 514 | 513 | 0.4 | |

L2 | CFRP2 | 832 | 960 | 15.3 | 737 | 940 | 27.6 | 903 | 1002 | 11.0 |

CFRP3 | 509 | 506 | 0.6 | 472 | 495 | 4.7 | 530 | 537 | 1.4 |

**Table 7.**Measured and predicted thickness of the deformed multilayered FML (temperature-dependent friction coefficient).

Lay-Up | Ply | Thickness at P1 (micron) | Thickness at P2 (micron) | Thickness at P3 (micron) | ||||||
---|---|---|---|---|---|---|---|---|---|---|

Measured | Predicted | Error (%) | Measured | Predicted | Error (%) | Measured | Predicted | Error (%) | ||

L1 | CFRP | 822 | 836 | 1.7 | 832 | 833 | 0.1 | 881 | 875 | 0.7 |

CFRP1 | 430 | 416 | 3.2 | 440 | 435 | 1.1 | 514 | 505 | 1.7 | |

L2 | CFRP2 | 832 | 860 | 3.3 | 737 | 714 | 3.1 | 903 | 920 | 1.9 |

CFRP3 | 509 | 520 | 2.1 | 472 | 495 | 4.8 | 530 | 528 | 0.4 |

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**MDPI and ACS Style**

Irani, M.; Kuhtz, M.; Zapf, M.; Ullmann, M.; Hornig, A.; Gude, M.; Prahl, U.
Investigation of the Deformation Behaviour and Resulting Ply Thicknesses of Multilayered Fibre–Metal Laminates. *J. Compos. Sci.* **2021**, *5*, 176.
https://doi.org/10.3390/jcs5070176

**AMA Style**

Irani M, Kuhtz M, Zapf M, Ullmann M, Hornig A, Gude M, Prahl U.
Investigation of the Deformation Behaviour and Resulting Ply Thicknesses of Multilayered Fibre–Metal Laminates. *Journal of Composites Science*. 2021; 5(7):176.
https://doi.org/10.3390/jcs5070176

**Chicago/Turabian Style**

Irani, Missam, Moritz Kuhtz, Mathias Zapf, Madlen Ullmann, Andreas Hornig, Maik Gude, and Ulrich Prahl.
2021. "Investigation of the Deformation Behaviour and Resulting Ply Thicknesses of Multilayered Fibre–Metal Laminates" *Journal of Composites Science* 5, no. 7: 176.
https://doi.org/10.3390/jcs5070176