Composite Tubular Structure Curing to Prevent Winding-Pultrusion Cracks
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Solution Overview
Problem
Existing composite rolls manufactured using the winding-pultrusion method exhibit significant mechanical property reductions due to cracking, which can lead to scrapping, despite their potential for higher stiffness and speed, necessitating an improvement in production reliability.
Innovation Solution
A method for manufacturing composite tubular structures by controlling parameters such as longitudinal modulus, transverse modulus ratio, carbon fiber distribution, fiber winding angle, resin cure rate, and resin type to ensure adequate adhesion and cracking resistance, thereby minimizing internal stresses and cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the winding-pultrusion method is used to manufacture composite rolls, then stiffness and production speed are improved, but cracking occurs leading to reduced mechanical properties and scrapping
Solution Approach 1:
The patent applies parameter changes by precisely controlling the fiber volume fraction in different zones (higher in pultruded spacers, lower in filament wound layers), the cure rate of resin (70-90% partial cure), and the fiber winding angle (30-45 degrees). These parameter optimizations ensure adequate adhesion between layers while minimizing internal stresses that cause cracking, thereby maintaining both high stiffness and production reliability
Solution Approach 2:
The patent implements preliminary action through partial curing of the resin (70-90% cure rate) before final assembly. This preliminary curing state allows the composite structure to achieve adequate adhesion and stress distribution before complete curing, preventing crack formation during the curing process while maintaining the high stiffness benefits of the winding-pultrusion method
2Productivity
If roller width and rotation speed are increased to improve production rate, then productivity is improved, but metal rollers suffer from deformation and vibratory behavior
Solution Approach 1:
The patent employs composite materials by combining carbon fiber reinforced polymers in a multi-layer winding-pultrusion structure. This composite construction provides high stiffness-to-weight ratio and superior dimensional stability compared to metal rollers, enabling increased roller width and rotation speed without experiencing the deformation and vibratory behavior that limit metal roller performance
Solution Approach 2:
The patent applies local quality by creating different structural zones within the roller: pultruded spacers with high fiber volume fraction for maximum stiffness at critical locations, and filament wound layers with optimized fiber angles for overall structural integrity. This localized optimization allows the roller to maintain stability at high speeds and large widths while achieving improved productivity
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 rates to virtually zero, ensuring consistent mechanical properties and production reliability, allowing for larger widths and higher rotation speeds while maintaining quality.
Implementation Method 1
a step of curing the manufacturing blank to obtain the composite tubular structure; the spacers and the winding layers are parameterized so as to have a lapshear and radial tensile strength at their interface which is greater than 15 MPa at the end of the manufacturing blank curing step
Data Source
AI summary
The present disclosure relates to a method for producing a tubular composite structure with a longitudinal axis, the method successively including a step of forming a manufacturing blank by stacking material to construct at least one tubular sandwich with a longitudinal axis, said tubular sandwich(S) comprising two filament winding layers based on raw resin and carbon fibers, and a series of pultruded spacers based on carbon fibers and at least partially cured resin, the pultruded spacers being arranged radially to the longitudinal axis between the two filament winding layers, and a step of curing the manufacturing blank to obtain the composite tubular structure.