3D Printer Tool Path Simulation for Warping and Stress Control

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Solution Overview

Problem

Existing 3D-printing technologies face challenges in predicting and minimizing residual stress and warping in additively manufactured parts due to thermal gradients, especially for complex geometries, leading to defects such as deformations and cracks.

Innovation Solution

A data processing system that performs thermal/structural simulations to optimize tool paths for 3D-printers by determining the order of mesh elements deposition, simulating incremental thermal and structural deformation, and modifying tool paths to account for volume changes caused by adjacent elements' deformations, thereby reducing warping and stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional 3D-printing methods are used without thermal/structural simulation, then manufacturing process is simpler and faster, but residual stress and warping defects increase

Engineering Contradiction:
Improvedimensional accuracyVSAvoidsimulation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system performs thermal and structural simulations before actual manufacturing to predict and optimize tool paths, preventing warping and residual stress defects before they occur. The simulation determines optimal deposition sequences and tool path parameters in advance, allowing the actual printing process to proceed with pre-optimized parameters that minimize defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates a virtual digital twin of the manufacturing process through simulation, where thermal and structural behaviors are modeled and analyzed before physical manufacturing. This digital copy allows testing and optimization of different tool paths and parameters without consuming physical material or risking actual part quality.

Inventive Principle:
Principle #26Copying

2Manufacturing precision

If thermal/structural simulations are performed to optimize tool paths, then warping and residual stress are reduced, but computational time and processing resources increase

Engineering Contradiction:
Improvewarping controlVSAvoidsimulation computational time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The simulation system divides the manufacturing process into discrete incremental steps, where thermal and structural analyses are performed for each deposition step. This segmentation allows the complex simulation to be broken down into manageable computational tasks that can be processed efficiently, with results accumulated to predict overall part behavior.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs simulations at multiple levels of detail, using simplified models for initial assessments and more detailed models only where needed. For routine deposits, standard thermal models are used, while critical regions requiring higher precision receive enhanced computational attention, balancing accuracy with computational efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If incremental deposit simulation is performed for each element, then thermal and structural characteristics are accurately determined, but processing complexity increases

Engineering Contradiction:
Improvethermal characteristic accuracyVSAvoidsimulation process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The simulation divides the part into a mesh of discrete elements and processes them in the sequence they are deposited during manufacturing. Each element's thermal and structural characteristics are calculated independently based on its specific deposition conditions, allowing accurate tracking of temperature history and stress accumulation throughout the build process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The simulation system automatically updates the thermal and structural state of each element based on its own deposition history and the state of previously deposited elements. The system self-adjusts by incorporating volume changes from structural deformation of adjacent elements, eliminating the need for manual intervention or simplified assumptions.

Inventive Principle:
Principle #25Self-service

4Manufacturing precision

If tool paths are optimized based on simulation results, then manufacturing quality improves, but manufacturing time increases

Engineering Contradiction:
Improvedefect reductionVSAvoidmanufacturing throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Optimal tool paths and deposition parameters are determined through simulation before actual manufacturing begins. The simulation identifies the sequence and parameters that minimize thermal gradients and structural deformation, allowing the physical manufacturing process to proceed efficiently with pre-optimized settings that reduce defects and rework.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system optimizes manufacturing parameters such as laser power, deposition rate, and tool path spacing based on simulation results. By adjusting these parameters within acceptable ranges to achieve optimal thermal and structural outcomes, the system maintains high productivity while improving part quality and reducing defects.

Inventive Principle:
Principle #35Parameter changes

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 system effectively minimizes defects in 3D-printed parts by optimizing tool paths, reducing warping, and improving mechanical strength, while also reducing manufacturing costs and time.

Implementation Method 1

instructions usable to drive the 3D-printer to move a laser to additively produce the part

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

simulate an incremental deposit of each of the elements of the mesh... determine thermal characteristics and structural deformation characteristics

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3369014B1System and method for optimizing tool paths based on thermal/structural simulations of a part being produced via a 3d-printer
Publication Date: 2021.11.03 SIEMENS INDUSTRY SOFTWARE INC
  • EP3369014B1 patent drawingFigure 1
  • EP3369014B1 patent drawingFigure 2
  • EP3369014B1 patent drawingFigure 3

AI summary

A system (100) and method is provided that facilitates optimizing tool paths based on thermal/structural simulations of a part (118) produced via a 3D-printer (142). A processor (102) may carry out a first simulation of the part being additively produced according to a first set of tool paths (110, 120) that correspond to instructions usable to drive the 3D-printer to produce the part. The first simulation may include: determining a hexahedral mesh (124) of the part that includes a plurality of hexahedron elements (122); determining an order of the elements of the mesh to deposit for additively producing the part based on the first set of tool paths; and simulating an incremental deposit of each of the elements (134) of the mesh in the order that the elements are determined to be deposited. For each incremental deposit of an additional respective element, thermal characteristics (128) and structural deformation characteristics (130) of the deposited elements are determined, in which some elements have a change in volume to account for a structural deformation of previously deposited adjacent elements (146).