Experimental and numerical investigation of fiber metal laminate forming behavior using a variable blank holder force

New Advances and Future Possibilities in Forming Technology of Hybrid Metal–Polymer Composites Used in Aerospace Applications

“…Hand lay-up Low cost of tooling [364,365] The process is simple [364] Large, complex parts can be formed [365] Flexible design [364] Production technology is easy to master [365] Any combination of fibres and matrix materials can be used [364] The process is time-consuming [364] Powder and bad smells are involved in the production environment [365] Quality of the final product depends on highly skilled manpower [364] The process is labour intensive [366] Spray lay-up Suitable for small-to medium-volume parts [364] Low-cost tooling [364] It is difficult to control the fibre volume fraction [364] There is difficulty in removing trapped air from the moulding [365] The process does not provide a good surface finish [364] RTM Complex parts can be fabricated [307,309,366] Higher volume outputs and much lower cycle times than other methods [308,366] Production of smooth-surfaced parts on both inner and outer surfaces of the mould [307,308,366]. Components can be produced up to 5-20 times faster compared with open moulding techniques [367] High production volumes require offset high tooling costs [307,308,367] Difficult to effectively improve the fibre volume content of the product [367] The size of the part is limited by the mould [308,367].…”

“…As a result, the air stream "imposes" the fibres and the resin on th mould surface [17,305,306]. RTM is a method of manufacturing laminates in closed forms, which consists o forcing catalysed resin into a tightly closed mould, previously filled with reinforcing fi bres and/or sandwich material [307][308][309]. The counter-mould is made similarly to th main mould.…”

“…The RTM/LRTM method allows the share of re inforcement in the total mass of the composite (over 60%) to be increased compared to for example, hand lay-up lamination [317]. RTM and LRTM technologies are mainly used RTM is a method of manufacturing laminates in closed forms, which consists of forcing catalysed resin into a tightly closed mould, previously filled with reinforcing fibres and/or sandwich material [307][308][309]. The counter-mould is made similarly to the main mould.…”

“…FML blank containing multi-directional fibre layers (0/45−45/90 • ) achieved better formability depth (42 mm) than unidirectional ones (35 mm). In 2020, Blala et al [308] improved the drawability of semi-cured Glare sheets in the deep drawing of cylindrical cups using a variable blank holder force (VBHF). Variation in the friction force of the holder and the laminate on contact surfaces varied as a function of the position of the outer flange edge (Figure 32).…”

Creep Age Forming of Fiber Metal Laminates: Effects of Process Time and Temperature and Stacking Sequence of Core Material

“…They concluded that by implementing the pre-curing processes before the deep drawing process, the dimensional accuracy could be considerably improved. Blala et al [3], using variable blank holder force, improved the drawability of FMLs in fabrication of cylindrical surfaces with the deep drawing process. Saadatfard et al [4] studied the drawability of FMLs in the hydromechanical drawing (HMD) process, concluding that necking happens at the lower metal sheet near the pole of the drawn part.…”