scholarly journals Numerical analysis of the energy-intesive components of the vehicle body

2018 ◽  
Vol 19 (9) ◽  
pp. 141-146
Author(s):  
Dominik Gałdyński ◽  
Damian Sobków
Keyword(s):  
Numerical Analysis ◽  
Welding Process ◽  
Strength Properties ◽  
Vehicle Body ◽  
Strength Parameters ◽  
The Subject ◽  
Thin Walled ◽  
The Impact

The subject of the publication concerns the numerical analysis of the strength parameters of models of thin-walled energy-intensive structures, which include crushed the front struts of vehicle. The impact of the welding process the partial front struts. The results of the analysis of the models of unrepaired and repaired structures, taking into account changes of strength properties in the SWC and weld areas, will be compared in order to estimate the loss of primary strength properties.

scholarly journals Stiffening material impact on the work of thin-walled element

2019 ◽  
Vol 252 ◽  
pp. 07009
Author(s):  
Katarzyna Falkowicz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Software Package ◽  
Epoxy Composite ◽  
Static Compression ◽  
The Subject ◽  
Linear And Nonlinear ◽  
Thin Walled ◽  
Quasi Static Compression

The subject of research is a numerical analysis of a thin-walled plate with a cut-out and stiffening, made of laminate and subjected to axial compression. The plate was made of a carbon-epoxy composite - a laminate consisting of eight symmetrically oriented plies. The scope of the research included a linear and nonlinear numerical analysis using Finite Element Method (FEM). The main objective of the study was to investigate behaviour of the considered plate made of various stiffening materials, under quasi-static compression to achieve Tsai-Wu criterion. The numerical analysis was conducted with the Abaqus, commercial FEM software package.

scholarly journals Changes in the Strength Properties and Phase Transition of Gypsum Modified with Microspheres, Aerogel and HEMC Polymer

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3486
Author(s):  
Justyna Ciemnicka ◽  
Karol Prałat ◽  
Artur Koper ◽  
Grzegorz Makomaski ◽  
Łukasz Majewski ◽  
...  
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Compressive Strength ◽  
Bending Strength ◽  
Strength Properties ◽  
Test Results ◽  
Strength Parameters ◽  
Scanning Calorimetry ◽  
Binding Material ◽  
The Impact

The paper presents an assessment of the impact of using additives on the strength of a binding material, i.e., building gypsum, and also the phase transformation that takes place in it. Microspheres, aerogel and polymer (HEMC) additives were added to a building gypsum slurry with a water to gypsum ratio of 0.75. In order to investigate their influence on bending strength, compressive strength, and the effect of high temperatures, differential scanning calorimetry (DSC), as well as tests of the multicomponent binder, were carried out in accordance with the applicable PN-EN 13279-2:2005 standard. The obtained test results allowed to determine that the used additives influenced the strength parameters of the obtained composites. It was shown that the applied additives decreased the compressive and bending strength of the modified gypsum. Despite these properties, the obtained gypsum materials are environmentally friendly because they reuse wastes, such as microspheres. Out of all the applied additives, the use of microspheres in an amount of 10% caused a decrease in the bending strength by only 10%, and an increase in the compressive strength by 4%.

scholarly journals The influence of technological errors on the corrosion degradation of the copper alloy from the cunifer group – CuNi10Fe1,6Mn

Mechanik ◽  
2019 ◽  
Vol 92 (5-6) ◽  
pp. 391-394
Author(s):  
Jakub Kowalski ◽  
Milena Supernak-Marczewska ◽  
Krzysztof Emilianowicz ◽  
Lech Nadolny
Keyword(s):  
Sea Water ◽  
Cooling System ◽  
Welding Process ◽  
Technical Condition ◽  
Corrosion Properties ◽  
Engine Cooling ◽  
The Subject ◽  
Technological Defects ◽  
Main Engine ◽  
The Impact

Copper and nickel alloys called cunifers (Cu, Ni, Fe and R – rest of alloy elements) have found wide application in the production of ship pipeline components in contact with sea water, such as, for example, the main engine cooling system. These alloys are characterized by a very high corrosion resistance, which is ensured by appropriately carried out passivation. However, with improperly carried out passivation, this material loses its anti-corrosion properties and is often corroded. In addition, a mistakenly conducted welding process is a factor conducive to degradation processes. The purpose of this work is to show the impact of errors created during the production process and pipeline testing for its technical condition. The subject of the research was a fragment of the pipeline made of CuNi10Fe1,6Mn alloy, coming from a vessel floating on sea waters. Macro- and microscopic examinations revealed a number of technological defects that affected the degradation of this element.

scholarly journals Experimental and Numerical Analysis of a Composite Thin-Walled Cylindrical Structures with Different Variants of Stiffeners, Subjected to Torsion

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3230 ◽  
Author(s):  
Tomasz Kopecki ◽  
Przemysław Mazurek ◽  
Tomasz Lis
Keyword(s):  
Numerical Analysis ◽  
Numerical Analyses ◽  
Modified Model ◽  
Cylindrical Structures ◽  
Local Loss ◽  
Thin Walled Structures ◽  
Non Linear ◽  
Thin Walled ◽  
Distribution Of Stress ◽  
The Impact

The aim of the study was to determine the impact of the use of isogrid stiffeners on the stress and displacement distribution of a thin-walled cylindrical shell made of layered composites subjected to torsion. It also strives to define criteria for assessing the results of non-linear numerical analysis of models of the examined structures by comparing them with the results of the model experiment. The study contains the results of experimental research using models made of glass–epoxy composites and the results of numerical analyses in non-linear terms. The experiment was carried out using a special test stand. The research involved two types of considered structures. The results of the research allowed to create the concept of an adequate numerical model in terms of the finite element method, allowing to determine the distribution of stress and strain in the components of the studied structures. Simultaneously, the obtained conformity between the results of non-linear numerical analyses and the experiment allows to consider the results of analyses of the modified model in order to determine the properties of different stiffening variants as reliable. The presented research allows to determine the nature of the deformation of composite thin-walled structures in which local loss of stability of the covering is acceptable in the area of post-critical loads.

scholarly journals Laboratory and Numerical Analysis of Steel Cold-Formed Sigma Beams Retrofitted by Bonded CFRP Tapes

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4339 ◽  
Author(s):  
Ilona Szewczak ◽  
Katarzyna Rzeszut ◽  
Patryk Rozylo ◽  
Sylwester Samborski
Keyword(s):  
Numerical Analysis ◽  
Numerical Models ◽  
Load Capacity ◽  
Steel Structures ◽  
Bottom Flange ◽  
Building Structures ◽  
Inner Surface ◽  
Carbon Fibre Reinforced Polymer ◽  
Thin Walled ◽  
The Impact

In this paper, the retrofitting method of thin-walled, cold-formed sigma beams using bonded carbon fibre reinforced polymer (CFRP) tapes is proposed. The effectiveness of the presented strengthening method is investigated by the means of laboratory tests and numerical analysis conducted on simply supported, single-span beams made of 200 × 70 × 2 profile by “Blachy Pruszyński” subjected to a four-point bending scheme. Special attention is paid to the evaluation of possibility to increase the load capacity with simultaneous limitation of beams displacements by appropriate location of CFRP tapes. For this purpose, three beams were reinforced with CFRP tape placed on the inner surface of the upper flange, three with CFRP tape on the inner surface of the web, three beams with reinforcement located on the inner surface of the bottom flange, and two beams were tested as reference beams without reinforcement. CFRP tape with a width of 50 mm and a thickness of 1.2 mm was used as the reinforcement and was bonded to the beams by SikaDur®-30 adhesive. Precise strain measurement was made using electrofusion strain gauges, and displacement measurement was performed using two Aramis coupled devices in combination with the Tritop machine. Numerical models of the considered beams were developed in the Finite Element Method (FEM) program Abaqus®. Experimental and numerical analysis made it possible to obtain a very high agreement of results. Based on the conducted research, it was proved how important is the impact of the applied reinforcement (CFRP tapes) in thin-walled steel structures, with respect to the classic methods of strengthening steel building structures.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

Managing Service Quality, Food Quality, Price Fairness and Customer Retention: A Holistic Perspective

2020 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Ammar Ahmed ◽  
Rafat Naseer ◽  
Muhammad Asadullah ◽  
Hadia Khan
Keyword(s):  
Service Quality ◽  
Food Quality ◽  
Service Sector ◽  
Customer Retention ◽  
Price Fairness ◽  
Policy Makers ◽  
Restaurant Management ◽  
The Subject ◽  
Research Propositions ◽  
The Impact

In this competitive environment, organizations strive to satisfy their customer by providing best quality service at affordable and fair prices with a view to enhance their revenues. To achieve the objective of revenue maximization, organizations strive to identify the factors that help them in retaining their customers. Drawing from the signalling theory of marketing, the current study proposes a novel conceptual model representing the impact of service quality with food quality and price fairness on customer retention in restaurant sector of Pakistan. The paper underlines an important arena of knowledge for academicians as well as organizational scientists on the subject. On the basis of literature available on the variables understudy, the present study forwards eight research propositions worthy of urgent scholarly attention. The conceptualized model of the present article can also be viewed significant in unleashing further avenues for the restaurant management entities, policy makers and future researchers in the domain of managing in the service sector businesses.

Solow economy model

2019 ◽  
pp. 150-157
Author(s):  
Oleksandr Synenko ◽  
Kateryna Yarema ◽  
Yuliia Bezsmertna
Keyword(s):  
Economic Growth ◽  
Regression Analysis ◽  
Solow Model ◽  
Economy Model ◽  
Accelerated Depreciation ◽  
Basic Parameters ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Model Algorithm

The subject of the research is the approach to the possibility of using the Solow model to perform the regression analysis on the example of the Ukrainian economy model. The purpose of writing this article is to investigate the notion of regres- sion analysis, Solow’s economy model, algorithm for performing regression analy- sis on the example of Ukraine’s economy model. This model can be adapted for the economy of enterprises. Methodology. The research methodology is system-struc- tural and comparative analyzes (to study the structure of GDP); monograph (when studying methods of regression analysis on the example of the Ukrainian economy); economic analysis (when assessing the impact of factors on Ukraine’s GDP). The scientific novelty consists the features of the use of the Solow model on the ex- ample of Ukrainian economy are determined. An algorithm for calculating the basic parameters of a model using the Excel application package is disclosed. The main recommendations on the development of the national economy and economic growth through the use of macroeconomic instruments are given. Conclusions. The use of the Solow model enables forecasting and analysis. The results obtained re- vealed the problem of low resource return of capital as a resource, along with the means of macroeconomic regulation of the investment process, using which can improve the situation. A special place in these funds belongs to the accelerated depreciation and interest rate policies.

Assessment of small businesses activities in Ukraine

2019 ◽  
pp. 40-47
Author(s):  
Igor Ponomarenko ◽  
Kateryna Volovnenko
Keyword(s):  
Comparative Analysis ◽  
Statistical Analysis ◽  
Small Business ◽  
Small Businesses ◽  
Government Agencies ◽  
Small Enterprises ◽  
The Subject ◽  
Business Entities ◽  
The Impact ◽  
Micro Enterprises

The subject of the research is a set of approaches to the statistical analysis ofthe activities of small business entities in Ukraine, including micro-enterprises. The purpose of writing this article is to study of the features of functioningof small business entities in Ukraine. Methodology. The research methodology isto use a system-structural and comparative analysis (to study the change in thenumber of small enterprises by major components); monographic (when studyingmethods of statistical analysis of small businesses); economic analysis (when assessing the impact of small business entities on socio-economic phenomena andprocesses in Ukraine). The scientific novelty consists to determine the features ofthe functioning of small businesses in Ukraine in modern conditions. The influenceof the activities of the main socio-economic and political indicators on the activities of small enterprises in recent periods of time has been identified. It has beenestablished that there is flexibility in the development of strategies by small businesses in conditions of significant competition, which makes it possible to quicklyrespond to changing situations in specific markets. Conclusions. The use of acomprehensive statistical analysis of small businesses functioning in Ukraine willallow government agencies to develop a set of measures to optimize the activitiesof these enterprises, which ultimately will positively affect the strengthening oftheir competitiveness and will contribute to the growth of the national economicsystem.

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