Composite Rudder Fin Weight Reduction

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Solution Overview

Problem

Conventional rudder fins for ships with high maneuverability requirements face challenges in reducing weight while maintaining sufficient stability under high rudder forces, often resulting in heavy metal structures that are cumbersome and costly to manufacture and maintain.

Innovation Solution

The rudder fin is constructed using a fiber composite material, particularly carbon fiber composite, which forms the outer surface and is reinforced with stiffening elements and foam cores to achieve significant weight reduction while maintaining strength and stability, with receiving joint elements integrated into the fin body for articulation with the rudder blade.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rudder fin is made of metal to ensure sufficient stability under high rudder forces, then the strength and stability are maintained, but the weight becomes excessively high

Engineering Contradiction:
Improvestrength and stabilityVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining fiber-reinforced plastic (such as carbon fiber, glass fiber, or aramid fiber) with foam core material to create a lightweight yet strong rudder fin structure. This composite construction achieves the necessary strength and stability under high rudder forces while dramatically reducing weight compared to traditional metal fins. The fiber-reinforced plastic provides tensile strength and rigidity, while the foam core adds structural stability and reduces weight.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If the rudder fin is made lighter to improve maneuverability and reduce forces required, then the ease of operation improves, but the stability under high rudder forces deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidstability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The composite material structure with fiber reinforcement provides sufficient stability under high rudder forces while maintaining reduced weight for improved maneuverability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by strategically orienting fiber reinforcements in specific directions within the fiber-reinforced plastic to match the stress patterns of rudder forces. The foam core is positioned to provide local structural support where needed, achieving optimal stability distribution throughout the fin structure while maintaining overall lightweight construction.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2251257B1Rudder flap
Publication Date: 2015.02.25 BECKER MARINE SYSTEMS GMBH & CO KG
  • EP2251257B1 patent drawingFigure 1
  • EP2251257B1 patent drawingFigure 2~3b
  • EP2251257B1 patent drawingFigure 4a~4b2

AI summary

In order to achieve improved properties in a fin (40) for a rudder (100) for watercraft, the fin (40) comprises fiber composite material.