Residual compressive strength of polyamide fiber‐reinforced epoxy composites after low‐velocity impact

Abstract

In this study, polyamide fibers, which stand out with their excellent plastic deformation and energy absorption capacity, were used as reinforcement materials, and in‐house manufactured composite specimens were subjected to low‐velocity impact (LVI), compression after impact (CAI) and tensile tests. Within this scope, one and two repeated drop tests were performed under 3 m/s velocity to determine LVI responses and how impact number affects the dynamic properties. CAI tests were also performed at a 1 mm/min crosshead speed, and mechanical properties for non‐impacted, one‐impacted, and two‐impacted specimens were determined. As a result of the outstanding plastic deformation capacity of thermoplastic fabrics, it is concluded that polyamide composites exhibited quite large strains. Furthermore, it was understood from the tensile responses that tensile stresses were carried by the thermoplastic fibers in two different regimes and significantly high toughness was obtained. Moreover, reductions in the maximum compression loads, critical buckling loads and axial stiffness were observed due to degradation in structural integrity after impact loads. Additionally, the utilization of recyclable thermoplastic polyamide fibers as reinforcement material instead of conventional reinforcement materials such as carbon and glass fibers provide more environmentally friendly products.

Exploration of impact response and damage mechanism of discontinuous CFRP laminates subjected to low velocity impact

“…Carbon fiber reinforced polymers (CFRPs) can realize outstanding mechanical performance in a wide range of applications; however, they are sensitive to normal impact stress. [1][2][3] CFRPs do not provide negligible warning when they undergo material failure during their service life because a fracture only results in low deformation. 4 In contrast, nacre from mollusk shells shows high strength and hardness, and it exhibits good toughness because of its three-dimensional "bricks and mortar" structure, as shown in Figure 1.…”

“…Carbon fiber reinforced polymers (CFRPs) can realize outstanding mechanical performance in a wide range of applications; however, they are sensitive to normal impact stress 1–3 . CFRPs do not provide negligible warning when they undergo material failure during their service life because a fracture only results in low deformation 4 .…”

Experimental investigation of impact resistance and compression behavior of CF/PEEK laminates after hot‐press fusion repair with different stacking sequences

“…The results demonstrated that Delamination propagation is the critical mechanism that lowers the sub‐laminate buckling strength of impacted specimens. Coskun et al 30 investigated one and two repeated impact tests that were performed at a 3 m/s constant velocity, and the effects of impact numbers on the dynamic properties. CAI tests were also conducted to determine the effects of repeated impact‐induced damages on residual compressive strength, as well as critical buckling load, peak force, and axial stiffness.…”

Influence of oxygen/argon duoplasmatron synergistic modification on the mechanical properties of UHMWPE/vinyl ester composites

“…It is found that under the same impact, the back of the large deformation laminate 10 has serious wrinkles and large delamination, which will lead to structural fluctuation of the laminate and reduce its performance 11 . For this reason, many researchers have studied the impact resistance 12 of composite laminates and concluded that laminates will show more complex deformation and failure mechanisms 13 . This is because all microstructures in the plate respond to external loading, and it is proved that delamination can effectively control the response and performance of the test 14,15 .…”