Composite Tubular Structure Layup to Reduce Cracking in Rollers

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Solution Overview

Problem

The implementation of the winding-pultrusion process for manufacturing rollers results in mechanical properties that are not consistent with the specifications, which can lead to the mechanical properties of the mechanical properties of the rollers being significantly reduced, leading to their rejection due to non-compliance with specifications.

Innovation Solution

A method for producing a tubular composite structure with specific parameterization of pultruded spacers and filament winding layers to achieve a longitudinal modulus between 52,300 KNm/Kg and 258,400 KNm/Kg, a transverse modulus ratio between 5 and 65, and a crack resistance greater than 100 J/m², with a fiber volume distribution and resin curing conditions optimized to minimize cracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the winding-pultrusion process is used to manufacture composite rollers, then the stiffness and weight performance are improved, but the mechanical properties become inconsistent with specifications

Engineering Contradiction:
ImprovestiffnessVSAvoidmechanical property consistency
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the fiber volume fraction (Vf) within specific ranges (50-65% for winding layers, 60-75% for pultruded layers) and adjusting resin viscosity (100-500 Pa·s) to ensure consistent mechanical properties. This systematic parameter optimization resolves the inconsistency in mechanical properties while maintaining high stiffness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials with optimized fiber-matrix composition, specifying carbon fibers with tensile strength ≥3500 MPa and elastic modulus ≥230 GPa combined with epoxy resins. The multi-layer composite structure with controlled fiber orientation and volume fractions ensures both high stiffness and reliable mechanical property consistency

Inventive Principle:
Principle #40Composite materials

2Strength

If pultruded spacers are added between filament winding layers, then the stiffness is significantly increased, but cracking occurs leading to reduced mechanical properties

Engineering Contradiction:
ImprovestiffnessVSAvoidcracking
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating distinct regions with different fiber volume fractions and material properties: the winding layers have Vf=50-65% while pultruded layers have Vf=60-75%. This local optimization ensures each region contributes appropriately to overall stiffness while reducing stress concentration that causes cracking

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses beforehand cushioning by incorporating a resin layer with viscosity of 100-500 Pa·s between the winding and pultruded layers. This resin layer acts as a cushioning interface that absorbs stress concentrations and prevents crack propagation, allowing the structure to achieve high stiffness without cracking

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If the fiber volume fraction is increased to improve mechanical properties, then the stiffness increases, but the resin impregnation becomes difficult

Engineering Contradiction:
Improvemechanical propertiesVSAvoidresin impregnation
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent resolves this contradiction through parameter changes by controlling fiber volume fraction within optimal ranges (50-65% for winding, 60-75% for pultruded) rather than maximizing it.同时, the resin viscosity is optimized to 100-500 Pa·s, which provides sufficient flowability for complete impregnation while still achieving high mechanical properties after curing

Inventive Principle:
Principle #35Parameter changes

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 significantly reduces cracking in composite rollers, ensuring mechanical properties meet specifications, thereby improving the manufacturing process. The method also allows for higher production rates and quality control.

Implementation Method 1

The present invention relates to a method for producing a tubular composite structure... two layers of filament winding based on raw resin and carbon fibers, and a series of pultruded spacers based on carbon fibers and resin at least partially cured

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Implementation Method 2

a manufacturing raw material curing step to obtain the composite tubular structure; in which the pultruded spacers and filament winding layers of the raw material are parameterized so as to ensure that the composite structure, obtained after the curing stage

Methodology Applied
Scientific EffectCuring:

Data Source

PatentEP4674604A1Method with increased reliability for manufacturing a composite tubular structure combining pultrusion and filament winding
Publication Date: 2026.01.07 EPSILON COMPOSITE
  • EP4674604A1 patent drawingFigure 1~2
  • EP4674604A1 patent drawingFigure 3~4
  • EP4674604A1 patent drawingFigure 5a

AI summary

The present invention relates to a method for producing a tubular composite structure with longitudinal axis (AX), the method comprising successively: - a step of forming a raw material (10) by means of constructing by stacking material at least one tubular sandwich (S) with longitudinal axis (AX), said tubular sandwich (S) comprising two layers of filament winding (11, 14) based on raw resin and carbon fibers, and a series of pultruded spacers (13) based on carbon fibers and resin at least partially cured, the pultruded spacers (13) being arranged radially to the longitudinal axis (AX) between the two layers of filament winding (11, 14); and - a step of curing the raw material (10) to obtain the composite tubular structure.