Composite Insert Structure for Detachable Fastening in Fiber Composites

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing composite elements with fibers bonded in resin face mechanical damage when screws or bolts are inserted, and gluing components results in irreversible attachment, making component replacement difficult and laborious.

Innovation Solution

Embedding an insert piece during composite element production, which hardens within the resin, allowing for the creation of fastening holes or projections that enable detachable connections without mechanical damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a screw or bolt is inserted into a composite element with cured resin, then a fastening connection is achieved, but mechanical damage occurs to the composite element

Engineering Contradiction:
Improvefastening connectionVSAvoidmechanical damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by embedding the insert into the composite element during the manufacturing process, before the resin cures. This pre-positioning eliminates the need for subsequent mechanical fastening operations that would damage the cured composite structure. The insert is integrated into the mold along with the fiber reinforcement, ensuring proper positioning and avoiding post-manufacturing damage.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If a component is bonded to a composite element, then attachment is achieved, but the component cannot be removed without damage

Engineering Contradiction:
ImproveattachmentVSAvoidcomponent replacement
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

The patent applies segmentation by separating the fastening function from the composite structure itself. The insert serves as an intermediate element that provides threading or fastening features, while the composite element remains intact. This allows the attached component to be removed and replaced by simply unscrewing or unfastening from the insert, without damaging either the component or the composite structure.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If an insert is embedded during manufacturing, then detachable connections become possible, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvedetachable connection capabilityVSAvoidmanufacturing process
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining the insert embedding step with the existing composite element manufacturing process. The insert is placed in the mold along with the fiber reinforcement and resin, and all components are cured together in a single operation. This integration eliminates the need for separate post-manufacturing operations to install fastening features, thereby reducing overall process complexity despite adding versatility.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables easy connection of components to composite elements without causing mechanical damage, allowing for easy removal and replacement of components without destroying the composite structure.

Implementation Method 1

a semi-finished product for the production of a fiber-reinforced composite element having a fastening hole or a fastening projection, as well as a composite element with fibers embedded in a cured resin

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP3701157B1Semifinished product for producing a fiber-reinforced composite element having a fastening hole or a fastening protrusion, composite element and method for producing a composite element
Publication Date: 2023.03.15 A RAYMOND & CO SCS
  • EP3701157B1 patent drawingFigure 1
  • EP3701157B1 patent drawingFigure 2
  • EP3701157B1 patent drawingFigure 3

AI summary

The invention relates to composite element (100), comprising fibers embedded in a hardened resin and comprising an insert piece (101) likewise embedded in the resin, which insert piece has a head (102) and a tip (103), a pin (104) being provided between the head (102) and the tip (103), which pin extends along a longitudinal axis (X), which points from the head (102) to the tip (103), wherein a fastening hole is introduced into the head (102) and/or a fastening protrusion (27) is provided on the head (102), and a recess is provided on the pin (104), at which recess a holding surface is formed, which is at an angle of > 0° and < 180°, in particular at an angle of > 10° and < 170° to the longitudinal axis (X) and which faces the head (102).