Study on Low-Velocity Impact Damage and Residual Strength of Reinforced Composite Skin Structure

Abstract

In order to better understand the damage tolerance of reinforced composite plates, the impact damage of the reinforced composite plates was investigated under low-velocity impact test. The experimental results show that the impact of different positions and energies causes different degrees of damage to the specimens, including but not limited to ply fracture, internal delamination of the skin, and debonding of the stiffeners and skin. After impacting, the specimens were tested in an axial compression. The results show that the ultimate bearing capacity of the specimen is also affected by different forms of impact. The impact point has the greatest influence on the specimen while it locates at the intersection of longitudinal and transverse bars. Compared with the intact specimen, the ultimate load carrying capacity was reduced by 16.83% and 44.02%, while the specimen impacted by 15 J and 30 J, respectively. The compression failure mode of the damaged specimen is mainly the breakage of the stiffeners and the delamination of the skin.

Enhancing Impact Energy Absorption, Flexural and Crash Performance Properties of Automotive Composite Laminates by Adjusting the Stacking Sequences Layup

“…In the case of BVID, it is preferable to use non-destructive techniques to detect internal damage that cannot be visually inspected. Several studies have used C-scan [ 41 , 42 ], NDT techniques and numerical simulations [ 43 ], optical fiber sensors [ 40 ], FBG-based sensors [ 44 ], acoustic emission [ 45 ], and guided wave signals [ 46 ] to evaluate and detect BVID in composite laminates. Because of their perforation at 15 J, all the stacking sequences recorded the highest peak load among other levels of impact energy in the same laminate structure ( Figure 8 , Figure 9 , Figure 10 ).…”

A novel methodology to research the residual compressive mechanical properties of composite stiffened panel after low velocity impact based on quantification damage simulation

“…Li et al [ 24 ] conducted a uniaxial CAI test to find the solution to diminish the negative influence on the residual compressive strength the multiple T‐shaped and I‐shaped stiffened CFRP panel when the impact location was the edge strip of the stiffener, and believed that choosing a proper stiffness ratio between the skin panel and the stiffener was an effective method to enlarge the residual compressive strength of the composite stiffened panel. Li et al [ 25 ] employed a CAI test to shed light on the relationship between the impact position and the ultimate failure load of the composite stiffened panel with transvers and longitudinal stiffener simultaneously, and supposed that the ultimate failure load would degenerate dramatically when the impact position was the intersection of the transvers and longitudinal stiffeners, and this phenomenon would become more serious with the increase of the initial impact energy.…”

Ultimate Load-Carrying Ability of Rib-Stiffened 2024-T3 and 7075-T6 Aluminium Alloy Panels under Axial Compression

“…They found that after the initial local buckling on the skin, the buckling mode jumps several times with the increase of load. The results of experiments on the impact damage of reinforced composite plates conducted by Li et al [ 19 ] showed that the energy under the low-velocity impact test causes different degrees of damage including debonding of the skin and stiffeners, and internal delamination of the skin. The stiffness and shape of the cross-section and of a stringer play an important role in its stability under axial load [ 20 , 21 ].…”