Variable Width Wire Element Placement for Composite Preform Coverage
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Solution Overview
Problem
The production of composite preforms with non-parallel wire elements for complex shapes like annular or ellipsoidal types faces challenges in achieving homogeneous coverage and mechanical properties, as existing methods struggle to properly orient reinforcing wire elements with respect to curvature lines of stress, leading to unsatisfactory mechanical characteristics and voids.
Innovation Solution
A method involving the adjustment of wire element width using calibration means to vary the distance between neighboring wire elements, allowing for precise orientation and deposition along curved surfaces, ensuring complete coverage and isotropy, with wire elements made of materials like carbon, ceramics, or glasses, and deposited at angles relative to the surface's curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If wire elements are deposited in non-parallel directions to achieve proper orientation with curvature lines, then mechanical properties are improved, but homogeneous coverage becomes difficult to achieve
Solution Approach 1:
The patent applies the dynamics principle by making the width of wire elements variable along their length. The wire elements are designed with widths that change dynamically according to the formula w(x) = w0 * (1 - kx/L), where the width decreases in the direction of convergence. This dynamic width adjustment allows non-parallel wire elements to converge and cover curved surfaces homogeneously while maintaining proper orientation with curvature lines, thus resolving the contradiction between mechanical properties and coverage uniformity.
Solution Approach 2:
The patent applies local quality by varying the width of wire elements at different positions along their length. Each wire element has a different width profile tailored to its specific location and orientation on the curved surface. This local adaptation of wire element geometry ensures that each element contributes optimally to homogeneous coverage while maintaining the required orientation with respect to curvature lines for mechanical strength.
2Manufacturing precision
If wire elements are made with variable width to achieve homogeneous coverage, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-defining the width profile of wire elements before deposition. The width variation w(x) = w0 * (1 - kx/L) is determined in advance based on the desired coverage geometry, and wire elements are manufactured with this predetermined variable width profile. This preliminary design approach simplifies the deposition process, as no complex real-time width adjustment mechanisms are needed during placement, thus reducing device complexity while maintaining manufacturing precision.
3Strength
If wire elements are deposited at angles to curvature lines for mechanical strength, then strength is improved, but void zones increase
Solution Approach 1:
The patent applies dynamics by using variable width wire elements that converge at angles to curvature lines while compensating for the increased spacing through width modulation. The width profile w(x) = w0 * (1 - kx/L) ensures that even though wire elements are oriented at angles for mechanical strength, their varying width compensates for the gaps between them, eliminating void zones and improving reliability while maintaining the beneficial angular orientation for strength.
Data Source
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AI summary
The method involves passing a fiber element (11 1) through a device for varying a width (l) of the element. The fiber element is deposited on a surface (S) for forming the deposited fiber element, where the width of the fiber element varies longitudinally along the surface. The width of the element is measured on the surface onto which the element is deposited, transversally to a middle fiber (12) of the fiber element. The fiber element is cut on exit from the device for obtaining a segment of fiber element having a specific length. Independent claims are also included for the following: (1) a method for manufacturing a preform (2) a preform comprising a set of fibrous sheets (3) a device for placing a fiber element on a surface.