Bonded Rotor Blade Cover Structure for Shear-Resistant Coupling
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Solution Overview
Problem
Gas turbine engine rotor blades require strong, durable, and lightweight designs that enhance performance, service life, and operating efficiency while resisting impact, stress, and fatigue, but existing designs face challenges in managing shear loading and stress distribution effectively.
Innovation Solution
The airfoil design features a bonded cover with internal and external ribs, corrugated coupling elements that engage with ribs to increase coupling strength, reduce shear loading, and provide mechanical, frictional, and adhesive coupling, enhancing durability and resistance to impact and stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a bonded cover design is used to reduce weight, then the airfoil becomes lighter, but the coupling strength between the cover and airfoil body is insufficient under high shear loading
Solution Approach 1:
The cover is divided into an inner cover and an outer cover that are separately bonded to the airfoil body, allowing each cover to be optimized for specific functions while distributing the bonding load across multiple interfaces
Solution Approach 2:
Coupling elements with complex three-dimensional geometries (including corrugated profiles, hooks, and interlocking features) are incorporated to engage with corresponding features in the airfoil body, creating mechanical interlocking that resists shear loading in multiple directions
2Ease of manufacture
If adhesive bonding is used to join the cover, then manufacturing is simplified, but the joint is insufficient resistant to shear loading and stress
Solution Approach 1:
The bonding system combines adhesive materials with mechanical coupling elements to create a composite joint that leverages both the flexibility and sealability of adhesives and the shear resistance of mechanical interlocking features
Solution Approach 2:
Corrugated coupling elements with curved profiles engage with corresponding curved features in the airfoil body, allowing the joint to accommodate thermal expansion and stress variations while maintaining strong mechanical coupling
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 design significantly improves the airfoil's resistance to impact, stress, and fatigue, extending service life and operational efficiency by effectively managing shear loading and stress distribution, and providing enhanced durability against foreign and domestic object damage.
Implementation Method 1
the coupling element extends along the internal cavity in cooperative engagement with the rib
Implementation Method 2
an inner cover bonded to the airfoil body over the internal cavity
Data Source
Figure 1
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AI summary
An airfoil (10) comprises an airfoil body (12) with an internal cavity (16) and inner and outer covers (32,34). The airfoil body defines a first major surface of the airfoil, and a rib (18) extends along the internal cavity. The inner cover (32) is bonded to the airfoil body (12) over the internal cavity (16), and includes a coupling element (20) extending along the internal cavity in cooperative engagement with the rib. The outer cover (34) is bonded to the airfoil body (12) over the inner cover (32), and defines a second major surface of the airfoil.