Structural elements based on the metamaterials

The article discusses an approach to creating structural elements by forming periodic structures in the structure, developed based on the results of topological optimization. In the article, a metamaterial is understood as a structure with a complex internal periodic organization of strength elements, the details of which are significantly smaller than the typical dimensions of the final structural product. In this paper, the analysis is devoted to panels with a filler based on periodic structures to achieve the required mechanical characteristics. The transition from the results of the topological optimization is carried out on the basis of engineering analysis, taking into account the particularities of loading, fastening and operational effects on the structure. The use of topology optimization makes it possible to determine the distribution density of periodic structures in the material and to shorten the design cycle of a conventionally optimal design. As a first step solution, authors consider panels based on sandwich panels with the pyramidal fillers. Their application is considered in the aircraft, shipbuilding and construction industries. As basic technological solutions, efficient technologies are proposed - laser radiation sources and a high degree of automation. With these technologies, efficiency and costs of testing and certification of manufacturing are reduced in comparison to the standard approaches, when results of the topology optimization are made using expensive additive manufacturing. The proposed elements make it possible to reduce the metal consumption while achieving the same rigidity and strength of the structure. Another advantage of the proposed structures is their modularity and the ability to optimize the panel filling density without significantly changing the manufacturing process and design. As an application, we considered the possibility of creating a large-span panel for civil constructions, which is characterized by high specific loads with a significant span length (20 m).

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Strut-and-tie models for linear and nonlinear behavior of concrete based on topological evolutionary structure optimization (ESO)

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952019000100008 ◽

2019 ◽

Vol 12 (1) ◽

pp. 87-100

Author(s):

R. M. LANES ◽

M. GRECO ◽

M. B. B. F. GUERRA

Keyword(s):

Nonlinear Behavior ◽

Structure Optimization ◽

Internal Flow ◽

Optimization Method ◽

Topological Optimization ◽

Structural Elements ◽

Stress Concentrations ◽

Progressive Reduction ◽

Strut And Tie ◽

Safety And Reliability

Abstract The search for representative resistant systems for a concrete structure requires deep knowledge about its mechanical behavior. Strut-and-tie models are classic analysis procedures to the design of reinforced concrete regions where there are stress concentrations, the so-called discontinuous regions of the structure. However, this model is strongly dependent of designer’s experience regarding the compatibility between the internal flow of loads, the material’s behavior, the geometry and boundary conditions. In this context, the present work has the objective of presenting the application of the strut-and-tie method in linear and non-linear on some typical structural elements, using the Evolutionary Topological Optimization Method (ESO). This optimization method considers the progressive reduction of stiffness with the removal of elements with low values of stresses. The equivalent truss system resulting from the analysis may provide greater safety and reliability.

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Numerical Experiments in Using Voronoi Cell Finite Elements for Topology Optimization

Volume 5: 35th Design Automation Conference, Parts A and B ◽

10.1115/detc2009-87460 ◽

2009 ◽

Author(s):

James M. Gibert ◽

Georges M. Fadel

Keyword(s):

Topology Optimization ◽

Isotropic Material ◽

Numerical Experiments ◽

Voronoi Cell ◽

Material Model ◽

Topological Optimization ◽

Advantages And Disadvantages ◽

Compliance Minimization ◽

Design Variables ◽

Standard Linear

This paper provides two separate methodologies for implementing the Voronoi Cell Finite Element Method (VCFEM) in topological optimization. Both exploit two characteristics of VCFEM. The first approach utilizes the property that a hole or inclusion can be placed in the element: the design variables for the topology optimization are sizes of the hole. In the second approach, we note that VCFEM may mesh the design domain as n sided polygons. We restrict our attention to hexagonal meshes of the domain while applying Solid Isotropic Material Penalization (SIMP) material model. Researchers have shown that hexagonal meshes are not subject to the checker boarding problem commonly associated with standard linear quad and triangle elements. We present several examples to illustrate the efficacy of the methods in compliance minimization as well as discuss the advantages and disadvantages of each method.

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Innovative Design, Structural Optimization and Additive Manufacturing of New-Generation Turbine Blades

Journal of Turbomachinery ◽

10.1115/1.4051936 ◽

2021 ◽

pp. 1-31

Author(s):

Lorenzo Pinelli ◽

Andrea Amedei ◽

Enrico Meli ◽

Federico Vanti ◽

Benedetta Romani ◽

...

Keyword(s):

Topology Optimization ◽

Additive Manufacturing ◽

Structural Optimization ◽

Turbine Blade ◽

Turbine Blades ◽

Topological Optimization ◽

Mode Shapes ◽

Structural Topology Optimization ◽

Structural Topology ◽

New Generation

Abstract The need for high performances is pushing the complexity of mechanical design at very high levels, especially for turbomachinery components. Structural topology optimization methods together with additive manufacturing techniques for high resistant alloys are considered very promising tools, but their potentialities have not been deeply investigated yet for critical rotating components like new-generation turbine blades. This research work proposes a methodology for the design, the optimization and the additive manufacturing of extremely stressed turbomachinery components like turbine blade-rows. The presented procedure pays particular attention to important aspects of the problems as fluid-structure interactions and fatigue of materials, going beyond the standard structural optimization approaches found in the literature. The numerical procedure shows robustness and efficiency, making the proposed methodology a good tool for rapid design and prototyping, and for reducing the design costs and the time-to-market typical of these mechanical elements. The procedure has been applied to a low-pressure turbine rotor to improve the aeromechanical behavior while keeping the aerodynamic performance. From the original geometry, mode-shapes, forcing functions and aerodynamic damping have been numerically evaluated and are used as input data for the following topological optimization. Finally, the optimized geometry has been verified in order to confirm the improved aeromechanical design. After the structural topology optimization, the final geometries provided by the procedure have been then properly rendered to make them suitable for additive manufacturing. Some prototypes of the new optimized turbine blade have been manufactured to be tested in terms of fatigue.

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COMPARATIVE STUDY OF STRESSES AND STRAINS THAT OCCUR IN STRUCTURAL ELEMENTS MADE OF COMPOSITE MATERIALS CONSIDERING THE MODEL WITH AND WITHOUT LAYERS

Journal of Engineering Studies and Research ◽

10.29081/jesr.v18i4.154 ◽

2016 ◽

Vol 18 (4) ◽

Author(s):

FLORENTINA TOCU ◽

COSTEL IULIAN MOCANU

Keyword(s):

Mechanical Properties ◽

Composite Material ◽

Mechanical Characteristics ◽

Building Industry ◽

Careful Study ◽

Structural Elements ◽

Ship Building ◽

Isotropic Plates ◽

Layer Composite ◽

Collective Experience

<p>Fibreglass-reinforced polyester (GRP) is the most widely used composite material in the ship building industry and requires careful study in point of mechanical characteristics. This article presents the collective experience related to behaviour in different situations of GRP loading. We considered three cases manufacturing for GRP: layers with mechanical characteristics for each layer, composite (the material is considered isotropic but with layers and same mechanical properties for all layers), and isotropic plates.</p>

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Topological optimization by designing structural elements of logging machine manipulators

Journal of Physics Conference Series ◽

10.1088/1742-6596/1515/4/042003 ◽

2020 ◽

Vol 1515 ◽

pp. 042003

Author(s):

S N Dolmatov ◽

P G Kolesnikov

Keyword(s):

Topological Optimization ◽

Structural Elements

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Evaluation of top-down mass spectrometry and ion-mobility spectroscopy as a means of mapping protein-binding motifs within heparin chains

The Analyst ◽

10.1039/d0an00097c ◽

2020 ◽

Vol 145 (8) ◽

pp. 3090-3099 ◽

Cited By ~ 2

Author(s):

Yunlong Zhao ◽

Igor A. Kaltashov

Keyword(s):

Mass Spectrometry ◽

Protein Binding ◽

Ion Mobility ◽

Structural Elements ◽

Client Protein ◽

Top Down ◽

Binding Motifs ◽

Ion Mobility Spectroscopy ◽

High Degree ◽

Top Down Mass Spectrometry

Identifying structural elements within glycosaminoglycans that enable their interaction with a specific client protein remains a challenging task due to the high degree of both intra- and inter-chain heterogeneity exhibited by this polysaccharide.

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Novel Non-Injection Approaches for Revealing and for Microscopic Investigation of the Microcirculatory Bed in Different Organs and Tissues

Microscopy and Microanalysis ◽

10.1017/s1431927600008527 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 327-328 ◽

Cited By ~ 1

Author(s):

N. Chilingaryan ◽

A. Chilingaryan ◽

M. Chilingaryan

Keyword(s):

Vascular Endothelium ◽

Microscopic Investigation ◽

Extensive Study ◽

Structural Elements ◽

Selective Precipitation ◽

Microcirculatory Bed ◽

Clear Cut ◽

Injection Methods ◽

Pathological Material ◽

High Degree

Certain disadvantages of traditional injection methods and difficulties arising during investigation of experimental and pathological material, limit the possibilities for extensive study of the microcirculatory bed (MCB). This has prompted the authors to develop new non-injection methods for revealing the MCB on histological sections by means of direct staining of the structural elements of the vessel wall. These methods are based on selective precipitation of the extra- or intracellular orthophosphates with ions of Zn, Cd, Co, Ca, Sr, and Pb in the vascular endothelium and smooth muscle cells. These methods (which we have called “histoangiological”) provide clear-cut contrast dyeing of the MCB in different organs and tissues as well as tumors in rat, cat,pig, dog, and in humans.In these methods, the reaction end product is lead sulfide which provides a high degree of contrast. Vessels and capillaries are detected due to precipitation of the deposit in the vascular endothelium.

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Improvement of Properties of the Argillaceous Soils when Using Additives "Chimston" in Combination with Inorganic Astringent

Materials Science Forum ◽

10.4028/www.scientific.net/msf.945.136 ◽

2019 ◽

Vol 945 ◽

pp. 136-140 ◽

Cited By ~ 2

Author(s):

Anna Ivanovna Trautvain ◽

Andrey Akimov ◽

E. Yakovlev

Keyword(s):

Soil Compaction ◽

Mechanical Characteristics ◽

Soil Stabilization ◽

Water Saturation ◽

Water Repellent ◽

Chemical Additives ◽

Key Characteristics ◽

Stabilized Soil ◽

High Degree ◽

Production Company

Paper observes research of the mechanical characteristics of the stabilized soil with different «Chimston» additives. Current work focuses on the application of the «Chimston-1» and «Chimston-2» produced by Zipo research and production company. Stabilized soil is based on local soils: argillaceous sand ground and sand clay. Chemical additives are mixed with water according to the manufacture’s recommendations. Amount of the «Chimston-1» is 0.07% of the soil. Amount of the «Chimston-2» is 0.01% of the cement. During the research plasticize effect is studied, based on maximum density and optimal humidity. Water saturation, mechanical strength under tension in bending and compression. It is established, application of the "Chimson" additives allow to increase key characteristics of the stabilized soil without increasing of the cement. «Chimston-1» additive has strongly pronounced plasticize effect which allow to increase soil compaction and decrease optimal humidity. Additive "Chimston-2" is a water repellent with a high degree of efficiency with soil stabilization.

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