Low-velocity impact of rectangular foam-filled fiber metal laminate tubes

Low-velocity impact response of glass/epoxy composite plates and fiber metal laminates with and without holes is investigated. The critical parameters that affect the delamination characteristics of laminates are impact energy, holes separation distance, type and directionality of fibers. An experimental investigation has been conducted to evaluate the effect of the presence of holes and the incorporation of aluminum layers in the extent of delamination. The extent of damage introduced during the impact event was observed on images obtained from C-scan non-destructive ultrasonic technique. Results indicate that fiber metal laminate made with aluminum layers exhibits an improved dynamic response in comparison with that of conventional laminates. The beneficial effect of using aluminum layers to reduce the extent of delamination produced by impact loading especially on laminates with holes is demonstrated. Furthermore, fiber metal laminates show better load carrying capability than conventional composite plates. The better response of fiber metal laminate with multidirectional fabric in comparison with fiber metal laminate with woven fabric is also examined. These results may be useful to better design the location of holes in composite structures.

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Experimental and numerical investigation on the effect of projectile nose shape in low-velocity impact loading on fiber metal laminate panels

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410018804384 ◽

2018 ◽

Vol 233 (10) ◽

pp. 3665-3679

Author(s):

H Ahmadi ◽

M Ekrami ◽

H Sabouri ◽

M Bayat

Keyword(s):

Numerical Simulation ◽

Failure Mechanisms ◽

Low Velocity Impact ◽

Aluminum Sheet ◽

Low Velocity ◽

Velocity Impact ◽

Conical Indenter ◽

Fiber Metal Laminate ◽

Nose Shape ◽

Fiber Metal

In this paper, low-velocity impact responses of 2/1 GLARE 3 (a commercial type of fiber metal laminate) specimens were studied experimentally and numerically. The effects of indenter's nose shape (flat, conical, and hemispherical) on energy absorption and failure mechanisms were thoroughly investigated. Drop weight testing machine with different impact energies was used for experimental tests and numerical simulation was also carried out. Failure mechanisms, such as delamination, debonding, aluminum sheet rupture, and composite laminate fracture, were discussed by sectioning the tested specimens. The results indicate that maximum and minimum contact force occurred with flat and conical indenters, respectively. Also, the target absorbs the utmost energy under the penetration of flat indenter and least energy during conical indenter perforation. It is depicted that the deflection at the peak load represents the main failure of the panel. Consequently, front aluminum sheet failure is determinant in fiber metal laminate panels impacted by flat and hemispherical indenters where back aluminum sheet is more significant for fiber metal laminate panels impacted by the conical indenter. Numerical simulation verified by experimental results is extended to lower impact weights and more velocities, which are discussed.

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