Erosion Protection for the AH-1G Low Radar Cross-Section Main Rotor Blade. Volume 1. Sand and Rain Erosion Evaluation

1977 ◽  
Author(s):  
Robert E. Head
Keyword(s):  
Cross Section ◽  
Rotor Blade ◽  
Radar Cross Section ◽  
Main Rotor ◽  
Main Rotor Blade ◽  
Rain Erosion ◽  
Erosion Protection

Modal Strain Energy Based Damage Detection Applied to a Full Scale Composite Helicopter Blade

2013 ◽  
Vol 569-570 ◽  
pp. 457-464 ◽  
Author(s):  
Fabio Luis Marques dos Santos ◽  
Bart Peeters ◽  
Herman van der Auweraer ◽  
Luiz Carlos Sandoval Góes
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Rotor Blade ◽  
Strain Energy ◽  
Full Scale ◽  
Experimental Results ◽  
Main Rotor ◽  
Helicopter Blade ◽  
Main Rotor Blade

The use of composites in the aircraft industry has generated a great need for structural health monitoring and damage detection systems, to allow for safer use of complex materials. Such is the case with helicopter blades - these components nowadays are mostly composed of carbon fiber or glass fiber reinforced plastics laminates, epoxy and honeycomb filled core structures. The use of composite materials on the main rotor blade also allows for more complex and efficient shapes to be designed, but at the same time, their use requires an additional effort when it comes to structural monitoring, since damage can occur and go unnoticed. This work presents experimental results for structural health monitoring method based on strain energy. The test subject is a full-scale composite helicopter main rotor blade, which is a highly flexible, slender beam that can display unusual dynamic behavior with orthotropic behavior. This damage detection method is based on the modal strain properties, and a damage detection index is used to identify and quantify damage. A test setup was built to carry out an experimental modal analysis on the main rotor blade. For that purpose, a total of 55 uniaxial accelerometers were used on the helicopter blade to measure the displacement modes of the structure. To compute the strain modes from the displacement modes, central differences approximation is used. Damage is introduced on the blade by attaching a small mass to two different locations. Experimental results show the possibility of locating damage in this case.

scholarly journals The Study on Durability Improvement of the Trim Tab for Main Rotor Blade of Rotorcraft

2021 ◽  
Vol 22 (7) ◽  
pp. 587-593
Author(s):  
Gwang-Eun Lee ◽  
Jeong-Mo Koo ◽  
Seong-Hyeon Na ◽  
Min-Ho Kim
Keyword(s):  
Rotor Blade ◽  
Main Rotor ◽  
Main Rotor Blade

A Case Study on the Air Flow Characteristics of the Hirobo-FALCON 505 Controllable Helicopter's Main Rotor Blade

2014 ◽  
Vol 527 ◽  
pp. 39-42 ◽  
Author(s):  
Ziad Bin Abdul Awal ◽  
Mohd Shariff bin Ammoo
Keyword(s):  
Flow Visualization ◽  
Rotor Blade ◽  
Flow Characteristics ◽  
Main Rotor ◽  
Through Flow ◽  
Visualization Process ◽  
High Kinetic Energy ◽  
Blade Tip ◽  
Helicopter Main Rotor ◽  
Main Rotor Blade

The aerodynamics of the helicopter rotor is one of the most elating and exigent tribulations faced by the aerodynamicists today. Study through flow visualization process plays a key role in understanding the airflow distinctiveness and vortex interaction of the helicopter main rotor blade. Inspecting and scrutinizing the effects of wake vortices during operation is a great challenge and imperative in designing effective rotor system. This study aimed to visualize the main rotor airflow pattern of the Hirobo-FALCON 505 controllable subscale helicopter and seek for the vortex flow at the blade tip. The experimental qualitative data is correlated with quantitative data to perform scrupulous study on the airflow behavior and characteristics along with its distinctiveness spawned by the main rotor blade. Simulation using design software is performed in analogous stipulations to endow with comparability between the flow visualization results. Throughout the blade span several dissimilar flow patterns have been identified. The main rotor hub has turbulent flow at its center due to low energy of air amassed in this region whereas in the middle portion of the rotor blade, the air encompasses high kinetic energy with a clear straight streamline pattern.

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