Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 8
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

This paper presents an approach based on NURBS (non-uniform rational B-splines) to achieve a seismic response surface (SRS) from a group of points obtained by using an analytical model of RC joints. NURBS based on the genetic algorithm is an important mathematical tool and consists of generalizations of Bezier curves and surfaces and B-splines. Generally, the accuracy of the design process of joints depends on the number of control points that are captured in the results of experimental research on real specimens. The values obtained from the specimens are the best tools to use in seismic analysis, though more expensive when compared to values simulated by SRSs. The SRS proposed in this paper can be applied to obtain surfaces that show site effect results on destructions of beam-column joint, taking into account different site conditions for a specific earthquake. The efficiency of this approach is demonstrated by the retrieval of simulated-versus-analytical results.

Go to article

Authors and Affiliations

R. Tabatabaei Mirhosseini
Download PDF Download RIS Download Bibtex

Abstract

An approach helpful when developing an optimized construction of a 6/4 type switched reluctance motor (SRM) is described in the paper. The analytical modeling procedure, based on the reluctance network method and analytical solution of an ordinary differential equation, enables applying a gradient optimization routine and better control of optimization process. The model allows for estimation of the efficiency, torque, and acoustic noise of the motor taking into account the magnetic non-linearity and the control algorithm to keep a constant input power. A bicriterial optimization routine has been applied to find optimal constructions. Eleven geometric and winding parameters are supposed to be the optimization quantities. Analyzed constructions – the initial one and the optimized ones, were validated by means of FEM calculations. The proposed approach can be employed in designing the SRM to be a drive motor in an electrical vehicle, at least as a first attempt.
Go to article

Authors and Affiliations

Wiesław Jażdżyński
Michał Majchrowicz
Download PDF Download RIS Download Bibtex

Abstract

This article proposes an analytical model of a system with priorities servicing a mixture of different elastic traffic streams. The model presented in the article was developed as the extension of earlier works published by the authors. It utilizes the concept of equivalent bandwidth and then, following bandwidth discretization, uses the dependencies introduced on the basis of the assumptions adopted for the generalized Kaufman-Roberts formula and for the model of a full-availability group with traffic compression. The article presents a possibility of using the proposed model to model the radio interface in a multi-service mobile network and provides an example of the above with the interface of an LTE network. Since the proposed model is an approximate one, the results of the calculations are compared with the results of simulations. A comparison of the results confirms an acceptable level of accuracy of the model. The model can be successfully used in the analysis and design of links and nodes of telecommunication and computer networks.

Go to article

Authors and Affiliations

B. Nowak
ORCID: ORCID
M. Piechowiak
M. Stasiak
P. Zwierzykowski
Download PDF Download RIS Download Bibtex

Abstract

A new expression is proposed to calculate the earth-energy of an earth-air-pipe heat exchanger during winter heating for three kinds of soil in France. An analytical model is obtained by using numerical computation developed in Scilab – a free open source software. The authors showed the comparison between their simple analytical model and experimental results. They showed the influence of different parameters to specify the size of the heat exchanger.

Go to article

Authors and Affiliations

Vincent M.F. Molcrette
Vincent A.R. Autier
Download PDF Download RIS Download Bibtex

Abstract

The paper presents analytical relationships based on the theory of Green’s functions. The relationships refer to instantaneous and continuous as well as point and ring heat sources which are discussed. The relationship relating to continuous ring source is the basis for modelling and designing of spiral ground heat exchangers. Heat transfer in the infinite and semi-infinite body was considered. In the latter case, the image method was discussed. Using the results of measurements regarding heat transfer in the ground with a heat exchanger in the form of a single coil installed, a comparison of calculated ground temperatures with measured values was presented.

Go to article

Authors and Affiliations

Barbara Larwa
Krzysztof Kupiec
Download PDF Download RIS Download Bibtex

Abstract

Vertical transport of wall-panels is a part of the prefabrication process of wood-framed buildings. The total dead weight of a wall is suspended on several lifting slings, pointwise clasping the top plate of the wall. This indicates, that all the weight of a wall is cumulated in sheathing-to-framing fasteners, usually staples. This article presents experimental investigations and analytical models evaluated for the description of light wood-framed walls in the process of lifting. Three different models cover the analytical approach: a model of a simple beam on elastic supports (BSS), a model of assembled beams (ACBS), three-dimensional (3D) spatial FE model of the wall (WFEM). Board-to-beam joint material parameters are determined on the base of experimental results. These connections are converted into two variants in the form of spring elements for 2D analysis, and beam elements for 3D analysis.
The numerical results exhibit that the proposed models may correctly represent behavior of a real wall in lifting, applying elastic materials parameters.
Go to article

Authors and Affiliations

Jarosław Malesza
1
Czesław Miedziałowski
1
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Wiejska 45A, 15-351 Bialystok, Poland
Download PDF Download RIS Download Bibtex

Abstract

Divorced eutectoid growth of cementite in AISI 1080 steel is investigated as a function of cooling rate for incomplete austenitization-based heat treatment. Furthermore, a fundamental mathematical relationship is established through analytical treatment that correlates divorced eutectoid growth with effective cooling rate and degree of undercooling in view of bulk diffusion controlled growth model. As the cooling rate increases, the divorced eutectoid growth of cementite is gradually ceased. The result predicted by the analytical model closely matches with the experimental result (%Deviation ≤ 7).

Go to article

Authors and Affiliations

Prasenjit Biswas
Joydeep Maity
Download PDF Download RIS Download Bibtex

Abstract

Dynamic characteristics for three types of railgun constructions were simulated and measured in this work. The simplest construction is the iron-less (IL) railgun, while the two other ones (IC and ICPM) have an iron-core. The iron-core permanent magnet (ICPM) railgun additionally has permanent magnets. To compare their characteristics, similar dimensions of the rails and iron cores were adopted, and the same power supply system was used. Numerical magnetic field analyses and our analytical models have been used to determine the electromagnetic parameters. They were verified experimentally. The transient states of the railguns were studied with our field-circuit mathematical model, and their results were also verified by experiments.
Go to article

Authors and Affiliations

Paweł Piekielny
1
ORCID: ORCID
Bronisław Tomczuk
1
ORCID: ORCID
Andrzej Waindok
1
ORCID: ORCID

  1. Department of Electrical Engineering and Mechatronics, Opole University of Technology, Prószkowska 76 str., 45-758 Opole, Poland

This page uses 'cookies'. Learn more