Topology optimization with geometrical constraints based on fictitious physical models (The geometrical constraint for molding and milling)

A basic pattern in the body plan architecture of many animals, plants and some molecular and cellular systems is five-part units. This pattern has been understood as a result of genetic blueprints in development and as a widely conserved evolutionary character. Despite some efforts, a definitive explanation of the abundance of pentagonal symmetry at so many levels of complexity is still missing. Based on both, a computational platform and a statistical spatial organization argument, we show that five-fold morphology is substantially different from other abundant symmetries like three-fold, four-fold and six-fold symmetries in terms of spatial interacting elements. We develop a measuring system to determine levels of spatial organization in 2D polygons (homogeneous or heterogeneous partition of defined areas) based on principles of regularity in a morphospace. We found that spatial organization of five-fold symmetry is statistically higher than all other symmetries studied here (3 to 10-fold symmetries) in terms of spatial homogeneity. The significance of our findings is based on the statistical constancy of geometrical constraints derived from spatial organization of shapes, beyond the material or complexity level of the many different systems where pentagonal symmetry occurs.

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Physical models from noncommutative causality

EPJ Web of Conferences ◽

10.1051/epjconf/201818202043 ◽

2018 ◽

Vol 182 ◽

pp. 02043

Author(s):

Nicolas Franco

Keyword(s):

Dirac Operator ◽

Causal Structure ◽

Wave Packets ◽

Physical Models ◽

Spectral Triple ◽

Geometrical Constraints ◽

Geometrical Explanation

We introduced few years ago a new notion of causality for noncommutative spacetimes directly related to the Dirac operator and the concept of Lorentzian spectral triple. In this paper, we review in a non-technical way the noncommutative causal structure of many toy models as almost commutative spacetimes and the Moyal-Weyl spacetime. We show that those models present some unexpected physical interpretations as a geometrical explanation of the Zitterbewegung trembling motion of a fermion as well as some geometrical constraints on translations and energy jumps of wave packets on the Moyal spacetime.

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Imposing geometrical constraint in topology optimization for additive manufacturing

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.18-00508 ◽

2019 ◽

Vol 85 (874) ◽

pp. 18-00508-18-00508

Author(s):

Takao MIKI ◽

Ayumu FURUTA ◽

Yuki SATO ◽

Takayuki YAMADA ◽

Kazuhiro IZUI ◽

...

Keyword(s):

Topology Optimization ◽

Additive Manufacturing ◽

Geometrical Constraint

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Topology Optimization Taking Into Account Geometrical Constraint of No-Closed Hole for Additive Manufacturing Based on Fictitious Physical Model Concept

10.1115/detc2021-66717 ◽

2021 ◽

Author(s):

Takayuki Yamada ◽

Yuki Noguchi

Keyword(s):

Topology Optimization ◽

Additive Manufacturing ◽

Physical Model ◽

Optimization Method ◽

Geometrical Constraint ◽

The Finite Element Method ◽

Model Concept ◽

Optimization Framework ◽

Proposed Model ◽

Topology Optimization Method

Abstract This paper proposes a topology optimization method that considers the geometrical constraint of a non-closed hole for additive manufacturing based on the fictitious physical model concept. First, the basic topology optimization concept and level set-based method are introduced. Second, the concept of a fictitious physical model for geometrical constraint in the topology optimization framework is discussed. Then, the model for the geometrical constraint of a non-closed hole for additive manufacturing is proposed. Numerical examples are provided to validate the proposed model. In addition, topology optimization considering this geometrical constraint is formulated, and topology optimization algorithms are constructed using the finite element method. Finally, optimization examples are provided to validate the proposed topology optimization method.

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Manufacturability evaluation for molded parts using fictitious physical models, and its application in topology optimization

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-017-0218-0 ◽

2017 ◽

Vol 92 (1-4) ◽

pp. 1391-1409 ◽

Cited By ~ 10

Author(s):

Yuki Sato ◽

Takayuki Yamada ◽

Kazuhiro Izui ◽

Shinji Nishiwaki

Keyword(s):

Topology Optimization ◽

Physical Models ◽

Molded Parts ◽

Manufacturability Evaluation

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Spatial Organization of Five-Fold Morphology as a Source of Geometrical Constraint in Biology

10.20944/preprints201808.0042.v1 ◽

2018 ◽

Author(s):

Juan López-Sauceda ◽

Jorge López-Ortega ◽

Jacobo Sandoval Gutiérrez ◽

Gerardo Abel Laguna Sánchez ◽

Ana Paola Rojas Meza ◽

...

Keyword(s):

Spatial Organization ◽

Cellular Systems ◽

The Body ◽

Measuring System ◽

Geometrical Constraint ◽

Spatial Homogeneity ◽

Geometrical Constraints ◽

The Many ◽

Computational Platform ◽

Pentagonal Symmetry

A basic pattern in the body plan architecture of many animals, plants and some molecular and cellular systems is five-part units. This pattern has been understood as a result of genetic blueprints in development and as a widely conserved evolutionary character. Despite some efforts, a definitive explanation of the abundance of pentagonal symmetry at so many levels of complexity is still missing. Based on both, a computational platform and a statistical spatial organization argument, we show that five-fold morphology is substantially different from other abundant symmetries like three-fold, four-fold and six-fold symmetries in terms of spatial interacting elements. We develop a measuring system to determine levels of spatial organization in 2D polygons (homogeneous or heterogeneous partition of defined areas) based in principles of regularity in a morphospace. We found that spatial organization of five-fold symmetry is statistically higher than all other symmetries studied here (three to ten-fold symmetries) in terms of spatial homogeneity. The significance of our findings is based on the statistical constancy of geometrical constraints derived from spatial organization of shapes, beyond the material or complexity level of the many different systems where pentagonal symmetry occurs.

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Recent Radiative and Collisional Atomic Data of Astrophysical Interest

International Astronomical Union Colloquium ◽

10.1017/s0252921100107596 ◽

1988 ◽

Vol 102 ◽

pp. 129-132

Author(s):

K.L. Baluja ◽

K. Butler ◽

J. Le Bourlot ◽

C.J. Zeippen

Keyword(s):

Mass Production ◽

Bound States ◽

Physical Models ◽

Impact Excitation ◽

Electron Impact Excitation ◽

Atomic Data ◽

Isoelectronic Sequence ◽

Astrophysical Interest ◽

Radiative Transitions ◽

Forbidden Transitions

SummaryUsing sophisticated computer programs and elaborate physical models, accurate radiative and collisional atomic data of astrophysical interest have been or are being calculated. The cases treated include radiative transitions between bound states in the 2p4and 2s2p5configurations of many ions in the oxygen isoelectronic sequence, the photoionisation of the ground state of neutral iron, the electron impact excitation of the fine-structure forbidden transitions within the 3p3ground configuration of CℓIII, Ar IV and K V, and the mass-production of radiative data for ions in the oxygen and fluorine isoelectronic sequences, as part of the international Opacity Project.

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Plastic Deformation in Microtomed Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066346 ◽

1971 ◽

Vol 29 ◽

pp. 458-459

Author(s):

J. Temple Black

Keyword(s):

Plastic Deformation ◽

Plastic Strain ◽

Applied Stress ◽

Elastic Strain ◽

High Strain ◽

Tool Material ◽

Cutting Edge ◽

Material Structure ◽

Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

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Cryo-TEM of amphiphilic polymer and amphiphile/polymer solutions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150216 ◽

1993 ◽

Vol 51 ◽

pp. 876-877

Author(s):

Yeshayahu Talmon

Keyword(s):

Microstructural Characterization ◽

Building Blocks ◽

Quantitative Information ◽

Physical Models ◽

Specimen Preparation ◽

Time Resolved ◽

Temperature Changes ◽

Temperature And Humidity ◽

Microstructured Fluids ◽

Air Streams

To achieve complete microstructural characterization of self-aggregating systems, one needs direct images in addition to quantitative information from non-imaging, e.g., scattering or Theological measurements, techniques. Cryo-TEM enables us to image fluid microstructures at better than one nanometer resolution, with minimal specimen preparation artifacts. Direct images are used to determine the “building blocks” of the fluid microstructure; these are used to build reliable physical models with which quantitative information from techniques such as small-angle x-ray or neutron scattering can be analyzed.To prepare vitrified specimens of microstructured fluids, we have developed the Controlled Environment Vitrification System (CEVS), that enables us to prepare samples under controlled temperature and humidity conditions, thus minimizing microstructural rearrangement due to volatile evaporation or temperature changes. The CEVS may be used to trigger on-the-grid processes to induce formation of new phases, or to study intermediate, transient structures during change of phase (“time-resolved cryo-TEM”). Recently we have developed a new CEVS, where temperature and humidity are controlled by continuous flow of a mixture of humidified and dry air streams.

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