Composite Propeller Blade Root With Hollow 3D-Woven Foot
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Solution Overview
Problem
The production of propeller blades for turboprop engines with compact, axisymmetric feet that can withstand various mechanical loads, including tensile, bending, and circumferential compression, is challenging due to the difficulty in manufacturing composite materials with 3D weaving and the integration of metal shells, which imposes additional constraints.
Innovation Solution
A method for manufacturing propeller blades using a fibrous reinforcement densified by a matrix, involving 3D weaving of a fibrous blank with a bulbous foot portion and internal housing, followed by resin injection and heat treatment to create a composite material blade with a compact, axisymmetric foot shape, incorporating an insertion element for mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If propeller blades are made from composite material with 3D weaving, then weight is reduced, but manufacturing complexity increases
Solution Approach 1:
The blade is divided into distinct functional zones with different fiber orientations: the foot portion uses longitudinal fibers for compression resistance, while the airfoil portion uses transverse fibers for tensile strength. This segmentation allows each region to be optimized for its specific mechanical requirements while being manufactured as a single integrated composite structure.
Solution Approach 2:
The invention employs composite materials with differentiated fiber orientations throughout the blade structure. The foot portion contains longitudinal fiber reinforcement for circumferential compression resistance, while the airfoil portion contains transverse fiber reinforcement for tensile strength, creating a multi-directional composite structure that optimizes strength-to-weight ratio.
2Adaptability or versatility
If foot dimensions are reduced for compact integration, then adaptability improves, but manufacturing precision requirements increase
Solution Approach 1:
The foot portion is designed with localized longitudinal fiber reinforcement specifically at the compression-prone areas, while the airfoil portion receives localized transverse fiber reinforcement. This local quality differentiation allows the compact foot geometry to achieve necessary strength properties without requiring increased overall dimensions.
Solution Approach 2:
The foot portion is given a bulbous or rounded geometry rather than a flat rectangular shape. This curvature distribution allows for compact integration into the rotor disc while providing gradual stress distribution that is easier to manufacture with controlled precision compared to sharp angular transitions.
3Strength
If metal shells are integrated into rotor disc, then structural strength improves, but additional compressive load increases
Solution Approach 1:
The foot portion contains localized longitudinal fiber reinforcement specifically oriented to resist the circumferential compression loads induced by metal shell integration. This targeted fiber placement provides enhanced compression resistance exactly where the metal shell applies stress, without requiring reinforcement throughout the entire blade.
Solution Approach 2:
The invention uses composite materials with longitudinal fiber reinforcement in the foot portion to counteract the circumferential compressive loads from metal shell integration. The composite structure combines the tensile strength of transverse fibers in the airfoil portion with the compression resistance of longitudinal fibers in the foot, creating a balanced multi-directional strength profile.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces a composite propeller blade with enhanced mechanical strength, suitable for variable-pitch systems, capable of withstanding centrifugal and compressive loads, and integrating seamlessly into rotor discs.
Implementation Method 1
the densification of the preform by a matrix to obtain a blade or propeller blade made of composite material
Data Source
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AI summary
The invention relates to a propeller blade or airfoil (10) for a turboprop engine, made from composite material and comprising a matrix-densified fibrous reinforcement, the propeller blade or airfoil comprising, in a spanwise direction (DL), a root (12) and an aerodynamic profile (11). The fibrous reinforcement comprises a fibrous preform having a three-dimensional weave with a root preform portion present in the root (12) and an aerodynamic profile preform portion present in the aerodynamic profile (11), the root and aerodynamic profile preform portions being joined to one another by the three-dimensional weave. The root preform portion of the fibrous preform comprises a break in the join, delimiting a housing inside the root forming a cavity (14) that opens at a free end (12a) of the root (12).