Topology optimization design of multi-scale structures with alterable microstructural length-width ratios

2019 ◽  
Vol 230 ◽  
pp. 111454 ◽  
Author(s):  
Quhao Li ◽  
Rui Xu ◽  
Ji Liu ◽  
Shutian Liu ◽  
Song Zhang
Keyword(s):  
Topology Optimization ◽  
Optimization Design ◽  
Multi Scale ◽  
Length Width ◽  
Scale Structures

Topology optimization design for buckling analysis related to the size effect

2021 ◽  
pp. 108128652110666
Author(s):  
Ning Gan ◽  
Qianxuan Wang
Keyword(s):  
Topology Optimization ◽  
Size Effect ◽  
Structural Design ◽  
Optimization Design ◽  
Couple Stress Theory ◽  
Classical Mechanics ◽  
Modified Couple Stress Theory ◽  
Small Scale ◽  
Scale Structures ◽  
Small Scale Structures

Owing to the excellent performance of microstructures or nanomaterials with well-designed topological configuration, the characteristic scale of structural design is gradually shifting from macroscopic to nanoscale or microscale structural design. However, the size effect that emerges from the small-scale structures may not be explained effectively with the hypothesis of classical mechanics owing to the lack of microscopic parameters in the classical constitutive model. In addition, slender beams within such small-scale structures are prone to buckling failure, which puts forward additional requirements for the stability design of the structure except for the overall compliance of the structure. Therefore, a topology optimization framework combining the modified couple stress theory with the solid isotropic material penalization (SIMP) model is constructed to illustrate the size effect on topology optimization. Numerical results show that the size effect affects the compliance, buckling performance, and topological configurations of the evolutionary structures.

scholarly journals Topology optimization of multi-scale structures: a review

2021 ◽  
Vol 63 (3) ◽  
pp. 1455-1480
Author(s):  
Jun Wu ◽  
Ole Sigmund ◽  
Jeroen P. Groen
Keyword(s):  
Topology Optimization ◽  
Rapid Development ◽  
Superior Performance ◽  
Future Research ◽  
Exciting Field ◽  
Seminal Paper ◽  
Computer Methods ◽  
Multi Scale ◽  
Research Questions ◽  
Scale Structures

AbstractMulti-scale structures, as found in nature (e.g., bone and bamboo), hold the promise of achieving superior performance while being intrinsically lightweight, robust, and multi-functional. Recent years have seen a rapid development in topology optimization approaches for designing multi-scale structures, but the field actually dates back to the seminal paper by Bendsøe and Kikuchi from 1988 (Computer Methods in Applied Mechanics and Engineering 71(2): pp. 197–224). In this review, we intend to categorize existing approaches, explain the principles of each category, analyze their strengths and applicabilities, and discuss open research questions. The review and associated analyses will hopefully form a basis for future research and development in this exciting field.

Spectral decomposition for graded multi-scale topology optimization

2021 ◽  
Vol 377 ◽  
pp. 113670 ◽  
Author(s):  
Tej Kumar ◽  
Saketh Sridhara ◽  
Bhagyashree Prabhune ◽  
Krishnan Suresh
Keyword(s):  
Topology Optimization ◽  
Spectral Decomposition ◽  
Multi Scale

scholarly journals A well connected, locally-oriented and efficient multi-scale topology optimization (EMTO) strategy

2021 ◽  
Author(s):  
Edouard Duriez ◽  
Joseph Morlier ◽  
Miguel Charlotte ◽  
Catherine Azzaro-Pantel
Keyword(s):  
Topology Optimization ◽  
Multi Scale

scholarly journals Principles of seed banks and the emergence of complexity from dormancy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jay T. Lennon ◽  
Frank den Hollander ◽  
Maite Wilke-Berenguer ◽  
Jochen Blath
Keyword(s):  
Global Change ◽  
Metabolic Activity ◽  
Cancer Biology ◽  
Life Sciences ◽  
Seed Banks ◽  
Tree Of Life ◽  
Multi Scale ◽  
Emergent Phenomena ◽  
Scale Structures ◽  
Emergence Of Complexity

AbstractAcross the tree of life, populations have evolved the capacity to contend with suboptimal conditions by engaging in dormancy, whereby individuals enter a reversible state of reduced metabolic activity. The resulting seed banks are complex, storing information and imparting memory that gives rise to multi-scale structures and networks spanning collections of cells to entire ecosystems. We outline the fundamental attributes and emergent phenomena associated with dormancy and seed banks, with the vision for a unifying and mathematically based framework that can address problems in the life sciences, ranging from global change to cancer biology.

scholarly journals A Novel GIS-Based Approach for Automated Detection of Nearshore Sandbar Morphological Characteristics in Optical Satellite Imagery

2021 ◽  
Vol 13 (11) ◽  
pp. 2233
Author(s):  
Rasa Janušaitė ◽  
Laurynas Jukna ◽  
Darius Jarmalavičius ◽  
Donatas Pupienis ◽  
Gintautas Žilinskas
Keyword(s):  
Satellite Imagery ◽  
Morphological Characteristics ◽  
Unsupervised Classification ◽  
Landsat 8 ◽  
Multi Scale ◽  
Medium Resolution ◽  
Wide Range ◽  
Position Index ◽  
Local Relief ◽  
Length Width

Satellite remote sensing is a valuable tool for coastal management, enabling the possibility to repeatedly observe nearshore sandbars. However, a lack of methodological approaches for sandbar detection prevents the wider use of satellite data in sandbar studies. In this paper, a novel fully automated approach to extract nearshore sandbars in high–medium-resolution satellite imagery using a GIS-based algorithm is proposed. The method is composed of a multi-step workflow providing a wide range of data with morphological nearshore characteristics, which include nearshore local relief, extracted sandbars, their crests and shoreline. The proposed processing chain involves a combination of spectral indices, ISODATA unsupervised classification, multi-scale Relative Bathymetric Position Index (RBPI), criteria-based selection operations, spatial statistics and filtering. The algorithm has been tested with 145 dates of PlanetScope and RapidEye imagery using a case study of the complex multiple sandbar system on the Curonian Spit coast, Baltic Sea. The comparison of results against 4 years of in situ bathymetric surveys shows a strong agreement between measured and derived sandbar crest positions (R2 = 0.999 and 0.997) with an average RMSE of 5.8 and 7 m for PlanetScope and RapidEye sensors, respectively. The accuracy of the proposed approach implies its feasibility to study inter-annual and seasonal sandbar behaviour and short-term changes related to high-impact events. Algorithm-provided outputs enable the possibility to evaluate a range of sandbar characteristics such as distance from shoreline, length, width, count or shape at a relevant spatiotemporal scale. The design of the method determines its compatibility with most sandbar morphologies and suitability to other sandy nearshores. Tests of the described technique with Sentinel-2 MSI and Landsat-8 OLI data show that it can be applied to publicly available medium resolution satellite imagery of other sensors.

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