A computational method for detecting aspect ratio and problematic features in additive manufacturing

Journal of Intelligent Manufacturing ◽

10.1007/s10845-021-01857-1 ◽

2021 ◽

Author(s):

Ruihuan Ge ◽

Joseph Flynn

Keyword(s):

Additive Manufacturing ◽

Aspect Ratio ◽

Thermal Stresses ◽

Computational Method ◽

Thin Wall ◽

Thin Walls ◽

Dimensionless Ratio ◽

Complex Features ◽

Further Development ◽

Metal Additive

AbstractIn metal additive manufacturing, geometries with high aspect ratio (AR) features are often associated with defects caused by thermal stresses and other related build failures. Ideally, excessively high AR features would be detected and removed in the design phase to avoid unwanted failure during manufacture. However, AR is scale and orientation independent and identifying features across all scales and orientations is exceptionally challenging. Furthermore, not all high AR features are as easy to recognise as thin walls and fine needles. There is therefore a pressing need for further development in the field of problematic features detection for additive manufacturing processes. In this work, a dimensionless ratio (D1/D2) based on two distance metrics that are extracted from triangulated mesh geometries is proposed. Based on this method, geometries with different features (e.g. thin wall, helices and polyhedra) were generated and evaluated to produce metrics that are similar to AR. The prediction results are compared with known theoretical AR values of typical geometries.By combining this metric with mesh segmentation, this method was further extended to analyse the geometry with complex features. The proposed method provides a powerful, general and promising way to automatically detect high AR features and tackle the relevant defect issues prior to manufacture.

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On-Line Compensation for Micromilling of High-Aspect-Ratio Straight Thin Walls

Micromachines ◽

10.3390/mi12060603 ◽

2021 ◽

Vol 12 (6) ◽

pp. 603

Author(s):

Yang Li ◽

Xiang Cheng ◽

Siying Ling ◽

Guangming Zheng

Keyword(s):

Aspect Ratio ◽

Cutting Parameters ◽

Thin Wall ◽

Dimensional Error ◽

Machining Quality ◽

Thin Walls ◽

Wall Deformation ◽

On Line ◽

Dimensional Errors ◽

Parameter Compensation

In order to improve the machining quality and reduce the dimensional errors of micro high-aspect-ratio straight thin walls, the on-line cutting parameter compensation device has been introduced and corresponding micromilling processes have been investigated. Layered milling strategies for the micromilling of thin walls have been modeled and simulated for thin walls with different thicknesses based on the finite element method. The radial cutting parameters compensation method is adopted to compensate the thin wall deformation by raising the radial cutting parameters since the thin wall deformation make the actual radial cutting parameters smaller than nominal ones. The experimental results show that the dimensional errors of the thin wall have been significantly reduced after the radial cutting parameter compensation. The average relative dimensional error is reduced from 6.9% to 2.0%. Moreover, the fabricated thin walls keep good shape formation. The reduction of the thin wall dimensional error shows that the simulation results are reliable, which has important guiding significance for the improvement of thin wall machining quality, especially the improvement of dimensional accuracy. The experimental results show that the developed device and the machining strategy can effectively improve the micromilling quality of thin walls.

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Innovation in additive manufacturing of parts from aluminium matrix composites

MATEC Web of Conferences ◽

10.1051/matecconf/201822401073 ◽

2018 ◽

Vol 224 ◽

pp. 01073 ◽

Cited By ~ 2

Author(s):

Tatiana Tarasova ◽

Galina Gvozdeva ◽

Riana Ableyeva

Keyword(s):

Surface Roughness ◽

Additive Manufacturing ◽

Formation Process ◽

Thin Wall ◽

Matrix Composites ◽

Modern Equipment ◽

Minimal Width ◽

Thin Walls ◽

Wall Structures

The laser build-up cladding is a well-known technique for additive manufacturing tasks. Modern equipment for the laser cladding enables material to be deposited with the lateral resolution of about 100 μm and to manufacture miniature parts. In this paper the laser micro cladding process was investigated to produce miniature thin-wall parts of Al-based composites. Thin walls formation process by subsequent single tracks overlapping with vertical increment was investigated. The influence of the cladding parameters on the minimal width and the quality of the fabricated thin walls was examined. The thin walls with the minimal width of 140 μm and surface roughness Ra 1,5 μm were generated. Laser micro cladding potential to manufacture lattice-shaped structures of Al-Si composites was shown. Fabricated thin-wall structures can have application in different fields e.g. aviation, automotive and tooling industries.

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DFT based computational methodology of IC50 prediction

Current Computer - Aided Drug Design ◽

10.2174/1573409916666200219115112 ◽

2020 ◽

Vol 16 ◽

Author(s):

Arijit Bag

Keyword(s):

Present Method ◽

Dipole Moments ◽

Research Work ◽

Organometallic Compounds ◽

Computational Method ◽

Unknown Compound ◽

Drug Designing ◽

Further Development ◽

Similar Kind ◽

Hiv 1

Background: IC50 is one of the most important parameters of a drug. But, it is very difficult to predict this value of a new compound without experiment. There are only a few QSAR based methods available for IC50 prediction which is also highly dependable on huge number of known data. Thus, there is an immense demand for a sophisticated computational method of IC50 prediction, in the field of in-silico drug designing. Objective: Recently developed quantum computation based method of IC50 prediction by Bag and Ghorai requires an affordable known data. In present research work further development of this method is carried out such that the requisite number of known data being minimal. Methods: To retrench the cardinal data span and shrink the effects of variant biological parameters on the computed value of IC50, a relative approach of IC50 computation is pursued in the present method. To predict an approximate value of IC50 of a small molecule, only the IC50 of a similar kind of molecule is required for this method. Results: The present method of IC50 computation is tested for both organic and organometallic compounds as HIV-1 capsid A inhibitor and cancer drugs. Computed results match very well with the experiment. Conclusion: This method is easily applicable to both organic and organometallic com- pounds with acceptable accuracy. Since this method requires only the dipole moments of an unknown compound and the reference compound, IC50 based drug search is possible with this method. An algorithm is proposed here for IC50 based drug search.

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