AM Distortion Compensation Using Physics-Based Shrinkage Modeling

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Solution Overview

Problem

Current additive manufacturing processes face significant distortion and residual stress issues, requiring expensive iterative methods that only compensate for spatial layout gaps, ignoring material shrinkage during the cooling phase, which affects shape accuracy.

Innovation Solution

A physics-based model is developed to compensate for material shrinkage by understanding the physical process of distortion, using non-uniform rational B-splines (NURBS) to generate a distortion compensated geometry, and iteratively adjusting process parameters to account for volume and shape changes during the cooling phase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional iterative distortion compensation methods are used, then shape accuracy is improved, but manufacturing cost and time increase significantly

Engineering Contradiction:
Improveshape accuracyVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing distortion compensation data in a lookup table before actual manufacturing. The system pre-processes distortion predictions for various geometric configurations and process parameters, so that during production, compensation can be applied directly without iterative calculations, significantly reducing manufacturing time while maintaining shape accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating a digital twin or virtual model of the manufacturing process that predicts distortion. This virtual model is used to generate compensation data that is then applied to the actual physical manufacturing process, avoiding the need for physical trial-and-error iterations and reducing both time and material waste

Inventive Principle:
Principle #26Copying

2Manufacturing precision

If spatial layout gap compensation is applied, then dimensional accuracy is improved, but material shrinkage during cooling is ignored leading to residual distortion

Engineering Contradiction:
Improvedimensional accuracyVSAvoiddistortion compensation completeness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by incorporating multiple physical parameters into the distortion prediction model, including material shrinkage rates, cooling rates, thermal conductivity, and phase transformation temperatures. The system dynamically adjusts compensation parameters based on these physical characteristics, moving beyond simple spatial layout compensation to a comprehensive physics-based approach that accounts for material behavior during cooling

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary physics-based distortion prediction model that bridges the gap between geometric design and actual manufacturing outcomes. This intermediary model simulates the thermal and mechanical fields during manufacturing, translating process parameters into predicted distortion patterns that can be compensated in advance

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If expensive iterative experiments are conducted to achieve distortion compensation, then shape accuracy is improved, but loss of time and resources increases

Engineering Contradiction:
Improveshape accuracyVSAvoidcompensation development time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent replaces mechanical trial-and-error experimentation with a computational simulation system. Instead of physically manufacturing test parts to measure and analyze distortion, the system uses finite element analysis and thermal-mechanical modeling to predict distortion patterns virtually, eliminating the need for repeated physical experiments and significantly reducing time and material consumption

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach enables rapid and efficient distortion compensation, eliminating the need for costly experiments and ensuring high-quality additive parts are produced within targeted geometrical and shape tolerances.

Implementation Method 1

determine a digital distortion model representing the physical target object including at least one distortion resulting from a manufacturing process of an AM fabricated product. The distortion may result from a manufacturing process of an AM fabricated product

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 2

The distortion may result from a manufacturing process of an AM fabricated product, for example, due to a phase transformation, plastic deformation, or residual stress

Methodology Applied
Scientific EffectPhase transformation: Phase Change

Implementation Method 3

For laser powder bed diffusion and laser directed energy deposition processes

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 4

additive manufacturing processes progressively add material to form a net shape or near net shape final component

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3467793B1Additive manufacturing process distortion compensation system
Publication Date: 2025.07.02 HAMILTON SUNDSTRAND CORP
  • EP3467793B1 patent drawingFigure 1
  • EP3467793B1 patent drawingFigure 2
  • EP3467793B1 patent drawingFigure 3

AI summary

An additive manufacturing (AM) system (100) comprising a process distortion compensation computing system (120) configured to determine a digital nominal model (170) that represents a physical target object excluding a distortion, and a digital distortion model (175) that represents the physical target object including at least one distortion. The AM system further comprises an AM peripheral device (150) configured to form a three-dimensional physical object based on a digital compensation model (190). The process distortion compensation computing system (170) determines a material volume difference between the digital nominal model (170) and the digital distortion model (175), and generates the digital compensation model (190) that compensates for the material volume difference.