Abstract
Nowadays, the concept of 3D-printing is well understood, as especially polymer-based units for individual private application can be found at low prices. But also, the industrial interest tends to be increasing day by day, especially regarding the metal-based processes like selective laser melting (SLM). In contrast to the well-known advantages of additive manufacturing, some of the main disadvantages are represented by the ability to produce components with reliable mechanical properties, especially for the reinforced implementation of additively manufactured structures in serial production processes. For this purpose, residual stresses are primarily challenging the discipline of part design and dimensioning. However, these challenges can be solved by the specific investigation of residual stress characteristics using numerical process analysis. The aim of this thesis is the numerical analysis of the SLM manufacturing process of AlSi10Mg-specimens and the experimental validation by residual stress measurements. Along with the description of the basic modelling strategy and identification of the main influencing factors, the possible influence of these factors on the resulting numerical residual stresses are investigated using parametric models. For this purpose, the parameters are categorized in process-related and user-related influencing factors, for which the firstly mentioned can be defined automatically or by the user for the numerical program itself and the secondly mentioned can be defined completely free during the modelling process. By comparing the numerical results of each parametric model with each other and with the residual stress measurements of AlSi10Mg-specimens using x-ray diffraction, suggestions for further numerical analysis and enhancements of the modelling process can be taken. As the numerical results have shown, the influences of the investigated parameters on the residual stress results are varying between negligible and significant. For instance, the process-related influencing factors without further calibration or investigation like the energy exposure fraction and \volumetric expansion factor have shown a significant impact on the residual stress results in deviations of up to -112% Among the user-related influencing parameters, two factors have shown significant impact behavior with deviations of up to +59% for the voxel size results and maximum deviations of residual stresses up to -177% for the amount of implemented structures, whereas others like the cutting direction or cutting height tend to have no recognizable effects on the residual stress results. Eventually, of all the analyzed models only one configuration matched the experimental stress results with acceptable deviation and therefore can be used as a standard model for further numerical analysis.
Translated title of the contribution | Numerical and experimental analysis of residual stresses in additive manufactured (SLM) AlSi10Mg-structures |
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Original language | German |
Qualification | Dipl.-Ing. |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 18 Dec 2020 |
Publication status | Published - 2020 |
Bibliographical note
embargoed until 11-11-2025Keywords
- numerical process analysis
- additive manufacturing
- AM
- selective laser melting
- SLM
- x-ray diffraction
- residual stress measuring