scholarly journals Topological optimization by designing structural elements of logging machine manipulators

2020 ◽  
Vol 1515 ◽  
pp. 042003
Author(s):  
S N Dolmatov ◽  
P G Kolesnikov
Keyword(s):  
Topological Optimization ◽  
Structural Elements

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

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.

scholarly journals TOPOLOGICAL OPTIMIZATION OF SHORT FIBERS REINFORCED COMPOSITE STRUCTURES CONSIDERING THE MATERIAL ANISOTROPY DETERMINED BY THE CALCULATION OF THEIR INJECTION MOLDING PROCESS

2020 ◽  
Vol 22 (5) ◽  
pp. 114-119
Author(s):  
E.I. Kurkin ◽  
◽  
E.A. Kishov ◽  
O.E. Lukyanov ◽  
O.U. Espinosa Barcenas ◽  
...  
Keyword(s):  
Injection Molding ◽  
Composite Structures ◽  
Topological Optimization ◽  
Injection Molding Process ◽  
Structural Elements ◽  
Short Fibers ◽  
Material Anisotropy ◽  
Molding Process ◽  
Sequential Convex Programming ◽  
Reinforced Composite

A methodology is presented for solving the related problem of topological optimization of short-reinforced composites structures, considering the attributes of the material anisotropy by fully solving the injection molding problem. The methodology is considered on the example of optimizing a bracket loaded with a shearing force. The solution is performed in the Ansys Topology Optimization module using the Sequential Convex Programming method. The anisotropic formulation of the problem involves the calculation of the injection molding process in the Autodesk Moldflow system on a mesh reduced by intermediate iterations of topological optimization, and updating the material properties at intermediate steps of the algorithm based on a C program. It is shown that the anisotropy of the material can lead to the displacement of weld lines beyond the main load-bearing structural elements and to increase the stiffness of short-reinforced composite materials structures.

scholarly journals Structural elements based on the metamaterials

2020 ◽  
pp. 211-219
Author(s):  
S. A Yurgenson ◽  
E. V Lomakin ◽  
B. N Fedulov ◽  
A. N Fedorenko
Keyword(s):  
Topology Optimization ◽  
Mechanical Characteristics ◽  
Distribution Density ◽  
Periodic Structures ◽  
Topological Optimization ◽  
Structural Elements ◽  
Metal Consumption ◽  
Radiation Sources ◽  
Design Cycle ◽  
High Degree

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).

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

Designing TIMP (tissue inhibitor of metalloproteinases) variants that are selective metalloproteinase inhibitors

2003 ◽  
Vol 70 ◽  
pp. 201-212 ◽  
Author(s):  
Hideaki Nagase ◽  
Keith Brew
Keyword(s):  
Three Dimensional ◽  
Therapeutic Interventions ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Structural Basis ◽  
Structural Elements ◽  
Ridge Structure ◽  
Extracellular Matrix Components ◽  
Metalloproteinase Inhibitors ◽  
The Matrix ◽  
A Disintegrin And Metalloproteinase

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.

Formation Of An Estimate For A State Contract With A Firm Price In The Construction Sector

2020 ◽  
pp. 47-57
Keyword(s):  
Construction Projects ◽  
Cost Of Capital ◽  
Federal Budget ◽  
The State ◽  
Structural Elements ◽  
Construction Sector ◽  
Construction Process ◽  
Practical Application ◽  
Stage Of Development ◽  
Capital Construction

The issues of determining the estimated cost of capital construction projects with the involvement of Federal budget funds at the stage of development of project documentation, during verification of the accuracy of determining the estimated cost and the initial (maximum) contract price are considered. On the basis of the assessment of amendments to urban planning legislation for the purpose of implementing a state contract by the contractor ( based on the results of competitive procedures or without competitive procedures by decision of state authorities), the procedure for forming the estimate as part of a state (municipal) contract, the price of which is firm, is presented. For the purpose of mutual settlements between the customer and the contractor for the work performed, the formation of primary accounting documentation, as well as for checking the work performed by regulatory authorities, an example of drawing up an estimate of the state (municipal) contract on the basis of grouping costs according to structural elements and complexes of work is given. The result of the research conducted was the development of regulations and the formation of criteria for their practical application by state bodies, institutions, organizations and other participants in the investment-construction process, as well as recipients of budget funds, who perform the functions of the state (municipal) customer, developer and technical customer.

Duality, Opposition and Typology in the Qur'an: The Apocalyptic Substrate

2008 ◽  
Vol 10 (2) ◽  
pp. 23-49 ◽  
Author(s):  
Todd Lawson
Keyword(s):  
Structural Elements ◽  
Prominent Feature ◽  
Apocalyptic Literature ◽  
Cultural Traditions ◽  
Bona Fide

This article highlights two features of Qur'anic style and content: duality/opposition and typological figuration, which can be seen as providing a continuous and consistent ‘narrative stream’ through the Qur'an. It is of some interest that both of these features have been singled out as distinctive of apocalypse as a genre in the study of numerous religious and cultural traditions. As debate on whether or not the Qur'an is a bona fide example of apocalyptic literature quietly continues, the interplay of conceptual and substantive oppositions and dualities is discussed in order to highlight the importance of this prominent feature to both the form and contents of the Book. It is suggested that its function is profoundly related to the typological figuration indispensable to the Qur'anic depiction of, for example, the character of the prophets and therefore prophethood. Whether or not this represents a genuine instance of apocalyptic literature, it nonetheless remains that the prominence of the motif renders the Qur'an susceptible of a reading expressive of something called an apocalyptic imagination. It is hoped that this article succeeds in demonstrating that in fact these apparently familiar subjects are stimulated to new life by considering them as defining, interlocking, structural elements of a distinctive Islamic apocalypse.

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