scholarly journals Optimization of the support structure of a multipurpose machine tool

2021 ◽  
Vol 284 ◽  
pp. 06013
Author(s):  
Aleksandr Yagopolskiy ◽  
Dmitry Tutukin ◽  
Nikolay Andryukhin ◽  
Dmitry Ivanov
Keyword(s):  
High Weight ◽  
Machine Building ◽  
Structural Elements ◽  
Support Structure ◽  
Modern Methods ◽  
Maximum Range ◽  
Multipurpose Machine Tool ◽  
Design And Manufacture ◽  
Efficiency And Productivity ◽  
Cutting Modes

Modern manufacturers of multipurpose machining centers design and manufacture equipment according to the criterion of maximum rigidity and productivity to ensure processing of the maximum range of materials at high accelerated cutting modes. As a result, in most machine-building tasks, the support structure of the machine is unnecessarily rigid due to the production of excessively massive frames and body elements of the machine. These structural elements have high weight and size characteristics, which leads to an increase in inertial loads on the drive feed mechanisms. In serial and mass production, heavy elements of the support structure significantly increase the energy consumption of the machine, while reducing labor productivity. Modern methods of design optimization, together with finite element methods, allow solving the problem of energy efficiency and productivity by modifying the support structures according to the criterion of minimum rigidity in accordance with the boundary conditions of the cutting forces when processing the selected product range.

scholarly journals The influence of the level of illumination of workplaces on working conditions (on the example of the Republic of Kazakhstan)

2021 ◽  
Vol 6 (2) ◽  
pp. 189-200
Author(s):  
R. B. Shirvanov
Keyword(s):  
Working Conditions ◽  
Occupational Diseases ◽  
Machine Building ◽  
Production Factors ◽  
Artificial Illumination ◽  
The Creation ◽  
The Republic ◽  
Questionnaire Method ◽  
Industrial Injuries ◽  
Efficiency And Productivity

The problem of industrial injuries and occupational diseases of workers is relevant for all countries, including the Republic of Kazakhstan, where more than 200 people die every year and more than 2,000 are injured at workplaces due to hazardous and harmful production factors, including insufficient natural or artificial illumination of workplaces. The aim of the work is to study the level of illumination of workplaces at enterprises of the Republic of Kazakhstan and to establish the influence of this factor on the working conditions. The object of the study is workplaces and employees of one of the largest machine-building plants, where 60 employees were interviewed, and instrumental measurements of illumination levels were performed in two workshops. The questionnaire method and methods for assessing workplaces by the level of illumination were used. The analysis showed that the largest number of surveyed workers (58.4%) were not satisfied with the level of illumination; according to the instrumental measurements of illumination, 40.9% and 46.6% of workplaces were harmful and dangerous. Employees working under harmful conditions are entitled to a number of benefits and compensations. Thus, the creation of rational working conditions, including illumination of workplaces, helps to minimize injuries and occupational diseases and increase the efficiency and productivity of labor. 

scholarly journals Perspectives of JIT system application at machine building enterprises

2021 ◽  
Vol 110 ◽  
pp. 04002
Author(s):  
Marina Samogorodskaya ◽  
Irina Beinar ◽  
Tatiana Narolina ◽  
Tatiana Smotrova
Keyword(s):  
System Application ◽  
Cost Accounting ◽  
Machine Building ◽  
Structural Elements ◽  
Organization Of Production ◽  
Building Enterprises

Тhe article describes the features of the Japanese system of management and organization of production JIT, shows its structural elements, analyzes the key conditions of use, identifies the main advantages of the JIT system. The features of the system of cost accounting and calculation within the framework of JIT are established, the factors hindering the use of the JIT system at Russian enterprises are determined.

scholarly journals Mechanical Properties of Glass Fiber Composites Reinforced by Textile Fabric

2015 ◽  
Vol 1 ◽  
pp. 133
Author(s):  
Arturs Macanovskis ◽  
Andrejs Krasnikovs ◽  
Olga Kononova ◽  
Galina Harjkova ◽  
Vladislav Yevstignejevs
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Polymer Matrix ◽  
Strength Properties ◽  
Machine Building ◽  
Structural Elements ◽  
Structural Element ◽  
Glass Fiber Composites ◽  
Material Volume ◽  
External Loads

<p class="R-AbstractKeywords"><span lang="EN-US">Interest to structural application of textile reinforced polymer matrix composite materials (CM) is growing during last years. In different branches of machine building, aerospace, automotive and others industries we can find structural elements preferably be produced using such reinforcement. At the same time, such materials are exhibiting elastic and strength properties scatter. In the framework of the present investigation, we observe yarn penetrated by a resin in a composite as a reinforcing “macro” fiber. Such “macro” fiber mechanical properties were measured experimentally, for this purpose was produced and was tested by tension until fracture fiber samples, having different length. Then was elaborated and was realized structural strength probabilistic model. In the textile geometry, was picked out repeating structural element – polymer matrix volume with two curved “macro” fiber’s chunks inside it. Complete composite material volume is possible to represent as a set of repeating structural elements. External loads application leads to disperse structural elements failure. Neighboring to ruptured elements are overloaded leading to higher probability to fail for them. Using FEM was modeled stress state in “macro” fibers inside CM. Then, was numerically obtained stress distribution in composite material, having different number of broken loops. Probabilities of different numbers of failed elements were calculated.  Strength probability function, based on Weibull approach was obtained. CM samples were tested under tension and obtained results were compared with numerical modeling as well as were analyzed.</span></p>

Load Bearing Structures of Glass Single-Storey Buildings

2016 ◽  
Vol 820 ◽  
pp. 39-44
Author(s):  
Eva Vojtekova
Keyword(s):  
Flat Glass ◽  
Structural Elements ◽  
Support Structures ◽  
Support Structure ◽  
Curtain Wall ◽  
Load Bearing ◽  
Roof Structure ◽  
Bearing Structure

Since the period of application curtain wall on skeleton buildings, small single–storey buildings are the great topic for architects. By various means architects have effort to create an impression of floating roof structure, or an illusion of levitating roof over the country. The effect of transparent space, overlapping interior and exterior, is possible to achieve by use of various structural schemes and materials of support structure. Nowadays single-storey transparent buildings are regarded as a phenomenon, which presents progress in architecture from the point of dematerialization of support structures and details of secondary transparent structures. Glass is in contemporary transparent curtain walls used not only as a material of the building skin, but also as the material of the support structure in various structural elements within hierarchy of the load bearing structure. Flat glass sheets forming the building skin could be within the suitable chosen shape of enclosed envelope also load bearing structure.

THE RATIONALE FOR THE ASSIGNMENT OF CUTTING DATA TO ENSURE THE REQUIRED QUALITY OF THE MATERIAL OF THE SURFACE LAYER DETAILS

2021 ◽  
pp. 3-17
Author(s):  
V. F. Bezjazychnyj
Keyword(s):  
Surface Layer ◽  
Initial Data ◽  
Quality Indicators ◽  
Practical Interest ◽  
Machine Building ◽  
Maximum Resistance ◽  
Surface Layer Quality ◽  
Required Quality ◽  
Cutting Modes

The justification of the feasibility of determining the cutting modes when processing with a blade tool with optimization to minimize the wear of the cutting wear is given, i.e. for its maximum resistance and at the same time to ensure the required quality indicators of the material of the surface layer of the part after processing. The initial data for the calculation and examples of calculating the cutting mode and surface layer quality indicators are given. Nomograms for determining the cutting modes, taking into account the quality indicators of the surface layer, are of practical interest for technologists of machine-building enterprises.

scholarly journals Experiment on Weight Efficient Support Structure by using Dynamic Opinionto Accommodate a Typical Sensor on Spacecraft

2019 ◽  
Vol 8 (6S4) ◽  
pp. 23-28
Keyword(s):  
Composite Materials ◽  
Modal Analysis ◽  
Artificial Satellite ◽  
Structural Elements ◽  
Efficient Design ◽  
Support Structure ◽  
Planetary Body ◽  
Modeling And Analysis ◽  
Cfrp Composite ◽  
Satellite Sensors

An artificial satellite is a human made structure, which is put into space around any planetary body to gather data and impart the equivalent information to ground stations. There is a huge requirement of several types of satellite sensors which are to be mounted on spacecraft or Satellite payloads. To accommodate sensors on Spacecraft, mounting structural elements are needed to support them. This project is mainly focused on the study of those mounting configurations with modeling and analysis of support structure used to mount Sensor in aerospace application. Different configuration of support structure modeled based on the frequency (100 Hz). These models were analyzed to optimize the mass. Work involves modal analysis of the structure made of aluminum and composite material (CFRP). The configuration of mounting structure for sensors is based on various constraints like interface requirements, functional requirement of sensor, stiffness, strength and most importantly the mass. Various configurations of the support structure have to be studied using modeling and analysis software keeping in view the stiffness requirement with minimum mass. For efficient design, composite materials are considered. Normal modal analysis will be carried out to understand the dynamic characteristics of the Mounting structure and the supporting structure was modeled using Al7075 and CFRP (Composite) materials and the results are compared in the present study

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.

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