Remote Fiber Optic Temperature Control in Induction Composite Welding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Controlling the temperature during induction welding of thermoplastic composite parts is challenging, leading to inconsistencies in weld quality if not performed within a specific temperature range.

Innovation Solution

The use of remote sensing technologies, specifically linear fiber optic sensors, to measure and control weld temperatures non-invasively, allowing for accurate temperature monitoring and adjustment of the induction welding process without the need for sensors at the weld interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are placed directly at the weld interface to measure temperature, then temperature measurement precision is improved, but weld strength deteriorates and device complexity increases

Engineering Contradiction:
Improvetemperature measurement precisionVSAvoidweld strength
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The patent uses an intermediary approach by placing the fiber optic sensor near the weld interface rather than directly at it, allowing temperature measurement through thermal conduction from adjacent material. This intermediary positioning enables accurate temperature monitoring while preserving weld integrity and avoiding contamination of the weld zone.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If sensors are placed directly at the weld interface to measure temperature, then temperature measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvetemperature measurement precisionVSAvoidsensor placement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor is positioned as an intermediary element near the weld interface, measuring temperature through thermal conduction from adjacent composite material rather than direct contact. This simplifies the overall system by eliminating the need for specialized high-temperature resistant sensors while maintaining measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If induction welding is performed without precise temperature control, then productivity is improved, but manufacturing precision deteriorates

Engineering Contradiction:
Improvewelding speedVSAvoidweld quality consistency
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements a feedback control system where the fiber optic sensor continuously monitors temperature at the weld interface, and this temperature data is fed back to control the induction heating process. This enables real-time adjustment of welding parameters to maintain optimal temperature ranges, ensuring consistent weld quality while maintaining productivity.

Inventive Principle:
Principle #23Feedback

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

This method enhances weld strength and reduces costs by ensuring consistent temperature control along the weld line, improving the quality and efficiency of the induction welding process.

Implementation Method 1

measuring temperatures along the weld line via the linear fiber optic sensor

Methodology Applied
Scientific EffectOptical frequency shift detection:

Implementation Method 2

During induction welding, fibers in the composite parts react to an applied magnetic field, resulting in heating at the composite parts

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 3

fibers in the composite parts react to an applied magnetic field, resulting in heating at the composite parts

Methodology Applied
Scientific EffectElectromagnetic field: Electromagnetic Induction

Data Source

PatentEP3772403A1Remote detection of induction weld temperature
Publication Date: 2021.02.10 THE BOEING CO
  • EP3772403A1 patent drawingFigure 1
  • EP3772403A1 patent drawingFigure 2
  • EP3772403A1 patent drawingFigure 3

AI summary

Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding of a composite part. The method includes locating a linear fiber optic sensor along a composite part comprising a matrix of thermoplastic reinforced by fibers, measuring temperatures along the weld line via the linear fiber optic sensor, performing induction welding at the composite part along the weld line, determining a continuum of weld temperatures along the weld line, and controlling the induction welding based on the continuum of weld temperatures.