scholarly journals EFFECTIVE METHOD OF SELECTING INTERFERENCE FIT BASED ON AUTOMATED COMPUTER MODEL CONSTRUCTION

2021 ◽  
Vol 1 (37) ◽  
pp. 103-109
Author(s):  
V. Nechyporenko ◽  
◽  
V. Salo ◽  
P. Litovchenko ◽  
L. Grebenik ◽  
...  
Keyword(s):  
Rational Design ◽  
Scientific Work ◽  
Geometric Parameters ◽  
Design Solution ◽  
Interference Fit ◽  
Shortest Distance ◽  
Working Length ◽  
Analytical Research ◽  
Parameter Values ◽  
Rational Standard

The proposed scientific work considers and substantiates an effective method for selecting interference fit on smooth cylindrical surfaces of parts, which can be successfully applied in automated design of fit. Based on the analysis of numerical and analytical research of the results of calculation and design of the considered joints, a flat image of a mathematical model of the area of existence of geometric parameter values in a two-dimensional coordinate system (diameter and working length of the fit) was first obtained. At the next stage of modeling many alternative i-th standard interference fits were built. Within each i-th object centers of grouping rational values of geometric parameters were defined. They are formed by crossing the largest segments of allowable ranges of changing values of diameter and working length in each of the models of sets. The position of such centers is analytically described using the mathematical apparatus of the theory of R-functions. On the considered specific example of this research, the criterion for choosing a rational standard interference fit is formulated depending on the values of geometric parameters. The meaning of this criterion is that within the flat geometric image of the model, the shortest distance is analytically determined - the segment between the points of the grouping centers of the model of set of the �-th fit and the model of the area of existence of values. The effectiveness and advisability of the formulated criterion is illustrated by comparison with other criterions obtained in previous researches of the authors. As a result of the research, it was revealed that the task of choosing a single rational design solution is significantly simplified if several criterions of one of the alternative fits coincide.

Rational Design Solution Based on Mathematical Modeling of an Interference Fit

2021 ◽  
pp. 73-80
Author(s):  
Vladimir Nechiporenko ◽  
Valentin Salo ◽  
Petro Litovchenko ◽  
Valeriya Rakivnenko ◽  
Andriy Horbunov
Keyword(s):  
Mathematical Modeling ◽  
Rational Design ◽  
Design Solution ◽  
Interference Fit

scholarly journals Constructing synthetic-protein assemblies from de novo designed 310 helices

2021 ◽  
Author(s):  
Prasun Kumar ◽  
Neil G. Paterson ◽  
Jonathan Clayden ◽  
Derek N. Woolfson
Keyword(s):  
Rational Design ◽  
De Novo ◽  
Protein Structures ◽  
Water Soluble ◽  
Design Solution ◽  
Protein Assemblies ◽  
Synthetic Protein ◽  
Hydrophobic Cores ◽  
Α Helix ◽  
Helical Folding

Compared with the iconic α helix, 310 helices occur much less frequently in protein structures. The different 310-helical parameters lead to energetically less favourable internal energies, and a reduced tendency to pack into defined higher-order structures. Consequently, in natural proteins, 310 helices rarely extend past 6 residues, and do not form regular supersecondary, tertiary, or quaternary interactions. Here, we show that despite their absence in nature, synthetic protein-like assemblies can be built from 310 helices. We report the rational design, solution-phase characterisation, and an X-ray crystal structure for water-soluble bundles of 310 helices with consolidated hydrophobic cores. The design uses 6-residue repeats informed by analysing natural 310 helices, and incorporates aminoisobutyric acid residues. Design iterations reveal a tipping point between α-helical and 310-helical folding, and identify features required for stabilising assemblies in this unexplored region of protein-structure space.

scholarly journals Determination of Rational Design and Geometric Parameters of a High-Performance Drill Based on a Mathematical Model of the Cutting Part

2021 ◽  
Vol 248 ◽  
pp. 04011
Author(s):  
Petr Pivkin ◽  
Vladimir Grechishnikov ◽  
Artem Ershov ◽  
Vladimir Kuptsov ◽  
Xiaohui Jiang
Keyword(s):  
High Precision ◽  
Load Distribution ◽  
Rational Design ◽  
Structural Parameters ◽  
Machine Building ◽  
Geometric Parameters ◽  
Cutting Edge ◽  
Processing Efficiency ◽  
Analytical Approaches ◽  
Rational Shape

Processing of high-precision holes in one technological operation is an urgent problem of advanced manufacturing. Processing of precise holes in parts for aerospace and machine-building industries with a diameter of up to 30 mm is performed during countersinking, deployment or grinding operations. These operations are applied only if there already exists a pre-treated hole. Monolithic three-fluted drills have been becoming common for processing high-precision holes of 7-8 quality over the last few years. The processing of various types of materials such as stainless steels, cast iron and heat-resistant steels requires rational geometric and structural parameters of the cutting tool. The nature of the load distribution between all the teeth during drilling plays a huge role in the processing efficiency. Even load distribution between the three teeth and a positive geometry improves self-centering and reduces the deviation from the specified axis of the hole. The drill sharpening provides positive geometry along the entire main cutting edge. The influence of the geometric parameters of the cutting edge of the screw groove on the shape of the drill bit is equally important. Existing approaches to the design of the thinning do not account for the influence of the geometric parameters of the cutting edge on the section of the screw groove. Analytical approaches to modelling of the main cutting edges are typically married with difficulties associated with achieving a smooth change in the angle of inclination to the tangent of the cutting edge. The complexity of the aforementioned task is largely due to the presence of critical points at the interface of the spiral groove and thinning. Determining the rational shape of two sections of the main cutting edge performed in this study is a complicated task that includes several steps needed to find the number of nodal points. Achieving a positive rake angle in the normal section to the cutting edge at the gash area that was formed via a special sharpening is one of the most important results of this paper. The rational shape of the cutting edge and the front surface provides an increase in the strength of the cutting part by 1.3 times.

scholarly journals Performance based approach in design of freeform space structures

2017 ◽  
Vol 15 (2) ◽  
pp. 153-166
Author(s):  
Miodrag Nestorovic ◽  
Predrag Nestorovic ◽  
Jelena Milosevic
Keyword(s):  
Design Process ◽  
Rational Design ◽  
Optical Measurement ◽  
Digital Fabrication ◽  
Digital Design ◽  
Physical Models ◽  
Design Solution ◽  
Roof Structure ◽  
Cad Cam ◽  
Context Specific

This paper is related to the fact that use of computational tools for form generation, analysis and digital fabrication (CAD/CAM/CAE) in an efficient way enables accurate representation of ideas, simulation of diverse impact and production of rational design solutions. Application of geometrical and numerical computational methods and adoption of performance based priorities enables formal exploration in constrained conditions and improvement of architectural engineering design process. Implementation of advanced technologies in 3D digital design process facilitates production of unconventional complex designs, their verification by construction of physical models and experimental diagnostics, as phase preceding construction of real structure. Within this work concept that provides design of non-standard, context-specific, freeform structure using rapid prototyping technology and 3D optical measurement will be reviewed. The analyzed design solution of roof structure above atrium of National Museum in Belgrade has a function to demonstrate the effectiveness of this approach.

Decomposing Incentives for Early Resilient Design: Method and Validation

2019 ◽  
Author(s):  
Daniel Hulse ◽  
Christopher Hoyle ◽  
Irem Y. Tumer ◽  
Kai Goebel
Keyword(s):  
Architectural Design ◽  
Design Method ◽  
Electric Power System ◽  
Design Solution ◽  
Design Representation ◽  
A Value ◽  
Cost Metrics ◽  
High Level ◽  
Parameter Values

Abstract Due to the expansive, time-consuming nature of risk analyses, it is important to be able to assign the minimization of risk (and, in general, optimization of resilience) to responsible teams that can work in parallel. However, while methods exist for minimization of risk in conventional design processes, research has not yet shown how it should be performed in a model-based design context in early design phase, when the design representation is relatively high-level and there are uncertainties in parameter values. This paper presents a value-driven design approach to minimize risk by decomposing the design, operational, and expected failure costs to individual functions in a system failure model. This process is demonstrated in a case study considering the redundancy of components to fulfill overall functions in an electric power system, where it is shown to increase design value significantly. An uncertainty-based process is additionally provided to enable the designer to test the sensitivity of the chosen design solution to uncertain parameter values. In this limited case study it is shown that the sensitivity of the choice to parameter value uncertainty is low, provided the range of uncertainty for each parameter is within a reasonable range. In situations like this, presented expected cost metrics provide meaningful information to justify system-architectural design decisions made on the basis of resilience.

Autonomous Oscillations, Bifurcations, and Chaotic Response of Moored Vessels

1988 ◽  
Vol 32 (03) ◽  
pp. 220-228
Author(s):  
Fotis A. Papoulias ◽  
Michael M. Bernitsas
Keyword(s):  
Phase Space ◽  
Rational Design ◽  
Single Point ◽  
State Equations ◽  
Dimensional Phase Space ◽  
Stability And Instability ◽  
Analysis Of Stability ◽  
Wave Drift Forces ◽  
Parameter Values ◽  
Selection Of

The dynamic behavior of single-point mooring (SPM) systems under time-independent external excitation is analyzed. The time evolution of the corresponding dynamical system is described in a six-dimensional phase space. Bifurcation sequences of state equations are studied and parameter values at which the response of the SPM changes radically are identified. Analysis of stability and instability domains of the system reveals regions of operationally hazardous response. It is shown that an SPM system under time-independent environmental excitation may not stay in a position of static equilibrium. It may start oscillating either periodically or even in a random way depending on the dimension of the attracting set in the phase space, which in general may be noninteger. This explains the large-amplitude slow motions of SPM systems, in the horizontal plane, occasionally observed in practice and often attributed to time-dependent excitation from wave drift forces. Based on these results, rational design decisions can be made for selection of the principal SPM geometric parameters in order to improve the system operability.

Improving the technology for the preparation of clay raw materials for the refractory production

2020 ◽  
pp. 10-13
Author(s):  
A. V. Yudin ◽  
S. Ya Davydov ◽  
R. A. Apakashev ◽  
V. S. Shestakov
Keyword(s):  
Mathematical Model ◽  
Rock Mass ◽  
Rational Design ◽  
Raw Materials ◽  
Refractory Production ◽  
Technical Solution ◽  
Clay Rock ◽  
Parameter Values

The technical solution of the screen with increased efficiency of separation of clay rock mass is considered. The most rational design of non-driven grate screens cantilever and spring-loaded screens — has been identified. A mathematical model is presented and a methodology for calculating the screen parameters is presented. It is shown that when selecting the appropriate parameter values for the grid-irons of the screening surface, the screens can be used for screening clay mass.

scholarly journals The choice of key geometric parameters in the numerical optimization of centrifugal compressor impellers

2018 ◽  
Vol 245 ◽  
pp. 09008 ◽  
Author(s):  
Vladimir Neverov ◽  
Yuri Kozhukhov ◽  
Sergey Kartashov ◽  
Vyacheslav Ivanov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Numerical Optimization ◽  
Optimization Problem ◽  
Geometric Parameters ◽  
Optimization Parameters ◽  
Standard Values ◽  
Parameter Values ◽  
Influence Degree

The article deals with the choice of key geometric parameters and the range of their variation in solving the optimization problem of centrifugal compressor impellers using computational fluid dynamics. The study was carried out using Numeca Fine / Turbo package. The influence of more than 10 geometric parameters on the efficiency and the head of the impeller was considered. The influence degree evaluation of investigated optimization parameters was provide by changing the parameters value in a preset range and analyzing their impact on the efficiency and head of the impeller. As a result, the main geometric parameters of optimization, which should be considered first, were identified. Other parameters may not be considered within the optimization problem, and can be assigned to the standard values. In addition, recommendations on optimal ranges of parameter values were given.

scholarly journals A Network of Type III Bricard Linkages

2015 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Matteo Zoppi ◽  
Simon D. Guest
Keyword(s):  
Case Studies ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Regular Hexagon ◽  
Analysis And Design ◽  
Type Iii ◽  
The Third ◽  
Planar Shape ◽  
Planar Shapes ◽  
Parameter Values

Among Bricard’s overconstrained 6R linkages, the third type has two collapsed configurations, where all joint axes are coplanar. The paper presents a one-degree-of-freedom network of such linkages. Using the two coplanar states of the constituent Bricard units, the network is able to cover a large surface with a specific outline when deployed, and can be folded compactly into a stack of much smaller planar shapes. Five geometric parameters describing each type III Bricard mechanism are introduced. Their influence on the outline of one collapsed configuration is discussed and inverse calculation to obtain the parameter values yielding a desired planar shape is performed. The network is built by linking the units, either using scissor linkage elements, if the thickness of the panels can be ignored, or with hinged parallelograms, for a thicker material. Two case studies, in which the Bricard network deploys as a rectangle and a regular hexagon, respectively, are presented, validating the analysis and design methods.

scholarly journals Design Approaches for Safety Increasing and Risk Decreasing for the Civil Aircraft’s Operation

2020 ◽  
Author(s):  
Dmytro Tiniakov
Keyword(s):  
Rational Design ◽  
Critical Incidents ◽  
Structural Features ◽  
Structure Design ◽  
Design Solution ◽  
Commercial Aircraft ◽  
Common Features ◽  
Civil Aircraft ◽  
Design Solutions ◽  
Structural Solutions

The safety and risks of civil aircraft operation depend on a lot of factors. One of them is the structural features of an aircraft. In aviation history, there are examples when “non-rational” design solution was the reason for crashes, but there are examples about successful civil aircraft that have “rational” structure and long operational time without critical incidents. So, how can a designer provide high safety of level and decrease incidents’ risks in time of a regular aircraft operation? This chapter partly can help to understand some reasons and approaches for providing “rational” aircraft structure. Design solutions can be divided into some groups by some common features and requirements. They are maintainability, serviceability, accessibility, labor effort decreasing, weather requirements, transportation, etc. All these groups depend on engineers’ structural solutions. They are interdependent and often contradictory. In other words, if one of the features will be better, another will be worse at the same time. And, a designer must remember all the time about this and try to find compromise between different requirements. The successful commercial aircraft is composed of a set of rational design solutions for these specific tasks.

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