Modern helicopter rotor blades are made of composite materials. Due to the harsh service environment, may be impacted by hail and other falling objects at low velocity. The damage behavior subjected low-velocity impact is studied here. Low-velocity experiment conducted on a blade, force measured. Based experiment, finite element model developed validated predict blade. With model, parametric study performed investigate effects energy, locations, foam core responses blades. results show that...

A set of polymer composite bolted T-joints with a novel configuration consisting an internal skeleton and external skin was fabricated using prepreg-RTM co-curing molding process. Experiments were conducted to study their mechanical properties under bending load. finite element model resin area between the established verified by experimental results. Then, damage propagation process failure mechanism joint influence three factors related layer characteristics investigated validated models....

Microvascular self-healing composite materials have significant potential for application and their mechanical properties need in-depth investigation. In this paper, the tensile compressive of woven fabric carbon fiber-reinforced polymer (CFRP) laminates containing three-dimensional microvascular channels were investigated experimentally. Several detailed finite element (FE) models established to simulate behavior laminate effectiveness different was examined. The damage propagation process...

Microvascular self-healing composite materials have significant potential for application and their mechanical properties need in-depth investigation. In this paper, tensile compressive of woven fabric carbon fiber reinforced polymers (CFRP) laminates containing three-dimensional microvascular channels were investigated experimentally. Several detailed finite element (FE) models established to simulate the behavior laminate effectiveness different examined. The damage propagation process...

Abstract Compressive performances of composite structures can be significantly decreased due to the lightning strike damage, so with frighten must considered protection design. In this study, compressive experiments after strikes were conducted on non‐protected, 12‐layer interlaminar carbon nanotube film (CNF) protected, and traditional surface silver coating (TSSC)‐protected laminates. A numerical analysis procedure was established, incorporating a ablation damage simulation (LSADS) module...

The tensile properties and damage behaviors of prepreg-resin transfer molding (RTM) co-cured composite bolted T-joints, consisting an internal skeleton external skin, were investigated through experimental numerical methods. With the validated finite element model, effects adding load-carrying beams, corner radius stacking sequence investigated. Results indicate that novel T-joint, weighing only 55.7% equivalent sized 2A12 aluminum can achieve 82% T-joint's stiffness 107% its proportional...

The copper mesh provides effective lightning strike protection for composite structures, while its efficiency can be compromised in scarf-repaired structures. In this study, after verified by test results, a numerical analysis procedure was employed to predict the ablation damage and residual bending performances of laminates with protection. Initially, mechanisms good repaired poor were analyzed. Then, impact attachment position repair design parameters including overlap length thickness...

Tests are conducted using stitched laminates in order to calculate the unnotched failure stress and compression after impact (CAI) strength of laminates. Unnotched laminates, with a hole, damage used tests. All specimens made two different types layup sequence three stitching directions - 0, 45, 90. In this paper, an FEM model is developed MSC PATRAN software predict CAI Two criteria applied strength, point criterion (PS) fiber breakage zone (FD) criterion. The influence moduli retention...

Composite structures used in aircraft are vulnerable to low-velocity impact and replacing them with new ones requires significant cost. Scarf-repair technique is an effective method restore the stiffness strength of damaged composite structures. Previous studies on scarf-repaired laminates have focused recovery efficiency, but limited attention has been directed toward properties. However, also sensitive impact. The residual worth investigating ensure safety In this study, experiments were...

A set of polymer composite bolted T-joints with novel configuration consisting internal skeleton and external skin was fabricated using a prepreg-RTM co-curing molding process. Experiments were conducted to study their mechanical properties under bending load. finite element model resin area between the established verified by experimental results. Then, damage propagation process failure mechanism joint influence three factors related layer characteristics investigated validated models. The...

A co-curing resin system consisting of 9368 epoxy for prepreg and 6808 transfer molding (RTM) was developed. corresponding preparation method a novel polymer composite bolted T-joint with internal skeleton external skin proposed based on the prepreg-RTM process, T-joints were fabricated. series conventional configuration RTM process made 2A12 aluminum alloy prepared simultaneously. Bending performances studied these experimentally. The results indicate that exhibit good compatibility in...