The influence of fibre orientation in aluminium–carbon laminates on low-velocity impact resistance

Abstract

The objective of this study was to assess the influence of fibre orientation in hybrid fibre metal laminates based on aluminium and carbon fibres on the impact of low-velocity impact. The analysis was conducted on the basis of fibre metal laminate impact resistance criteria, including impact force, energy absorption, bending stiffness, damage area and failure. To assess the resistance of various aluminium–carbon laminates, qualitative and quantitative evaluation criteria were employed, including the shape of the force–time curve, characteristic impact forces, energy absorption, bending stiffness, damage area and external failure analysis. Among others, authors concluded that no explicit influence of the composite layer fibre orientation on the shape and value of characteristic forces was observed. It was found that the fibre orientation and the changing number of interfaces of low durability show no explicit influence on the size and shape of delaminations.

The Effect of Layer Thicknesses in Hybrid Titanium–Carbon Laminates on Low-Velocity Impact Response

“…The maximum differences in share of damage in the total area of the laminate are 0.6%, 0.44%, 4.64%, and 2.84% for strokes with energy of 5, 15, 30, and 45 J, respectively. At the same time, it can be seen that the damage analysis of HTCL with various metal content and number of interfaces correlates with the observations of curves representing energy changes over time, where a greater ability to absorb impact energy of HTCL with a lower MVF coefficient was recorded, precisely due to the increased share of composite destruction, especially at the metal composite phase boundary and/or the boundaries of composite layers arranged perpendicularly to each other [16,41].…”

“…It is possible to estimate the value of the energy absorbed (E a (t)) by the laminate during the process of impact [16]. Dependencies (2)-(5) are the solution of calculations of the absorbed energy based on experimental data such as displacement, velocity, and force.…”

“…The energy absorption process in impact time is presented in Figure 5. The energy-time curves are characterized by the stage of energy increase to a maximum value equal to the kinetic energy of the striking body just before its contact with the laminate and the subsequent decrease in energy to a value depending on the material's energy absorption capacity [16,23,24]. It was noticed that as the energy increases, the difference between maximum energy and absorbed energy changes.…”

“…However, in the case of a laminate with MVF = 0.6, after impact with energies of 5 and 15 J and the MVF = 0.375 laminate subjected to 15 J impact energy, an irregular shape of the surface of the destruction was observed, forced by the orientation of fiber arrangement in the laminate. The aforesaid results from the dominant role of propagation of delamination at the border of layers with different fiber orientation in the total damage [16].…”

“…The second element of critical significance for impact resistance is laminate structure. Due to the almost unlimited possibilities of designing the structure of FML laminates, e.g., by using different thicknesses of individual layers, different numbers of metal and composite layers, or using different fiber arrangements [16,17], it is possible to design their properties to match specific requirements. One of the basic parameters describing the structure of FML laminates is their metal volume fraction (MVF), among others [1].…”