Composite Strut Reinforcement for Compression Load Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Composite tubular struts used in applications like aerospace often require over-sizing to handle compression loads effectively, leading to increased cost and weight, as their compressive strength is generally lower than tensile strength.

Innovation Solution

Incorporating a sleeve-like reinforcement around a laminated core of the strut, which can be made of materials like titanium or ceramic, to enhance compressive strength while maintaining a lightweight design, and using corrugations to control wrinkling during consolidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the strut is over-sized to carry compression loads, then the compressive strength is improved, but the weight and cost increase

Engineering Contradiction:
Improvecompressive strengthVSAvoidstrut weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention uses a hybrid composite structure combining fiber-reinforced resin laminates with a metal tubular reinforcement (titanium, aluminum, or stainless steel). The metal reinforcement provides superior compressive strength while the composite laminate maintains tensile strength, creating a composite structure that meets both compression and tension load requirements without excessive weight

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metal tubular reinforcement is nested within the fiber-reinforced resin laminate core, with the reinforcement positioned centrally along the longitudinal axis. This nested configuration allows the stronger metal material to bear compression loads internally while the outer composite laminate provides tensile strength and structural integrity

Inventive Principle:
Principle #7Nested doll (Nesting)

2Strength

If the strut is over-sized to carry compression loads, then the compressive strength is improved, but the cost increases

Engineering Contradiction:
Improvecompressive strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The hybrid composite construction allows optimization of material usage by placing high-strength metal reinforcement only where compression loads are most critical (within the laminate core), rather than using expensive metal throughout the entire strut structure, thus reducing overall material cost while maintaining required strength

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metal reinforcement is positioned locally within the laminate core at specific locations along the strut length where compression loads are highest, rather than uniformly distributing material throughout. This localized reinforcement strategy reduces material costs while maintaining adequate compressive strength

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2790898B1Composite strut and fabrication method
Publication Date: 2018.01.10 THE BOEING CO
  • EP2790898B1 patent drawingFigure 1
  • EP2790898B1 patent drawingFigure 2~3
  • EP2790898B1 patent drawingFigure 4~5

AI summary

A columnar structure comprises a generally hollow laminate core (34), an outer composite skin (42), and a sleeve-like reinforcement (36). The reinforcement (36) of metal or ceramic for example surrounds the laminate core (34) and is sandwiched between the core and the out¬ er skin (42) for reacting compressive loads imposed on the columnar structure.