Dynamic Analysis of the Structure of Automobile Components, Obtained by Powder Metallurgy

2020 ◽  
Vol 896 ◽  
pp. 119-126
Author(s):  
Anca Didu ◽  
Nicolae Dumitru ◽  
Cristina Ileana Pascu ◽  
Violeta Cristina Contoloru
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Models ◽  
Combustion Engine ◽  
Practical Interest ◽  
Wide Field ◽  
Connecting Rod ◽  
Time Frequency ◽  
Different Types ◽  
Automobile Components

The analysis of the dynamic behavior of parts from the structure of the cationing mechanism of an internal combustion engine in 4 steps is followed. Thus, kinetic and dynamic models were developed for the motor mechanism considered as an assembly consisting of crankshaft, connecting rods, bearings and pistons. Dynamic models were built mainly in the Ansys program, based on the finite element method. The following problems were addressed, namely the dynamic analysis, with the determination of the response in time for displacements, stresses and deformations and also the vibration analysis in order to analyze the frequency response for the kinematic parameters of the whole system, but also of the component elements. Dynamic models for the numerical processing of the two types of analyzes were designed in a parameterized system with multiple possibilities of working on different time, frequency or different types of loadings and connection conditions. The purpose of this paper is to study the dynamic response of the main elements of the mechanism, for different types of materials. Given the wide field of applicability in automobiles, the technology for obtaining parts from sintered powders, the studies were realized for the cases when the connecting rod and the bearings are made of metallic powders, respectively of steel, to be extended for more complex cases, when we consider the influence of lubricant and temperature distribution in areas of practical interest.

Nonlinear Dynamics of Single-Cylinder Flexible Reciprocating Engines

2003 ◽  
Author(s):  
I. Goudas ◽  
I. Stavrakis ◽  
S. Natsiavas
Keyword(s):  
Dynamic Models ◽  
Equations Of Motion ◽  
Direct Determination ◽  
Numerical Results ◽  
Valuable Insight ◽  
Connecting Rod ◽  
Single Cylinder ◽  
Strongly Nonlinear ◽  
Reciprocating Engines

In the present study, dynamic response of single-cylinder reciprocating engines is investigated. The models examined take into account the flexibility of the engine mechanism associated with either its connecting rod or its supporting bearings. In addition, both the driving and the resisting moments are expressed as functions of the crankshaft motion. This leads to dynamic models with equations of motion appearing in a strongly nonlinear form. These equations are then solved numerically, by employing methodologies of both the time and the frequency domain. In particular, these methodologies include determination of transient response by direct integration or direct determination of complete branches of steady state response. The first set of numerical results refers to engine mechanisms with a flexible connecting rod. After dealing briefly with the special case of constant crank angular velocity, which can be investigated more easily and provides valuable insight into some aspects of the system dynamics, the emphasis is shifted to the general case of non-ideal forcing. Next, numerical results are presented for engine models with flexible bearings. Initially, mechanisms with rigid members supported by bearings involving linear anisotropic or isotropic properties are considered. Finally, similar results are also presented for hydrodynamic bearings, whose behavior is governed by the classical finite-length impedance theory. In all cases, the attention is focused on investigating the influence of the system parameters on its dynamics.

Dynamic and Modal Analysis of a Snake like Robot

2020 ◽  
Vol 896 ◽  
pp. 203-210
Author(s):  
Leonard Marius Ciurezu-Gherghe ◽  
Nicolae Dumitru ◽  
Ionuţ Daniel Geonea ◽  
Cristian Copiluși
Keyword(s):  
Dynamic Analysis ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Vibration Modes ◽  
Time Frequency

In this paper a modal and dynamic analysis of a snake like robot is performed. Modal analysis consist in determination of own vibration modes and natural frequencies. The proposed dynamic analysis was performed in order to determine the variation time/frequency laws for the cinematic and dynamics parameters.

scholarly journals Real Driving Range in Electric Vehicles: Influence on Fuel Consumption and Carbon Emissions

2021 ◽  
Vol 12 (4) ◽  
pp. 166
Author(s):  
Carlos Armenta-Déu ◽  
Erwan Cattin
Keyword(s):  
Fuel Consumption ◽  
Electric Vehicles ◽  
Carbon Emissions ◽  
Combustion Engine ◽  
Polluted Environment ◽  
Characteristic Parameters ◽  
Different Types ◽  
Driving Range ◽  
Daily Trip

This paper is focused on the determination of real driving ranges for electric vehicles (EV’s) and how it influences fuel consumption and carbon emissions. A precise method to evaluate the driving range of an EV can establish the correct reduction in GEI amount, mainly CO and CO2, ejected to the environment. The comparison of the daily driving range between an internal combustion engine (ICE) vehicle and an EV provides a useful tool for determining actual fuel saved during a daily trip and a method to compute carbon emissions saved depending on the type of ICE vehicle. Real driving range has been estimated on the basis of a daily trip consisting of five different segments, acceleration, deceleration, constant speed, ascent and descent, which reproduce the different types of driving. The modelling has been developed for urban routes since they are the most common and the most polluted environment where the use of electric vehicles is applied. The effects of types of driving have been taken into account for the calculation of the driving range by considering three main types of driving: aggressive, normal and moderate. The types of vehicle in terms of shape and size as well as dynamic conditions and the types of roads have also been considered for the determination of the driving range. Specific software has been developed to predict electric vehicle range under real driving conditions as a function of the characteristic parameters of a daily trip.

Population Change, Modernization and Welfare. By Joseph Spengler. Prentice-Hall Inc., Englewood Cliffs, N.J. 1974.

1977 ◽  
Vol 16 (2) ◽  
pp. 220-222
Author(s):  
Zeba A. Sathar
Keyword(s):  
Population Growth ◽  
Population Change ◽  
Population Control ◽  
Stable Condition ◽  
Developed Countries ◽  
Wide Field ◽  
Wide Scale ◽  
Socio Economic Variables ◽  
Almost All

The book covers a wide field, touching on almost all aspects of popula¬tion change on a world-wide scale. It discusses, using world and country data, the relationships between demographic and socio-economic variables, and elaborates on" their relative importance in the determination of population problems which confront the world as a whole and nations individually. Policies designed to alleviate these problems are discussed with an emphasis on those related to population control. The first chapter is entitled "Population Growth: Past and Prospective" and reviews the various parameters associated with population change in the past and in the future. It touches upon the concept of a stable population in order to show the elements which cause a population to change (i.e. remove it from its stable condition). The main elements of change, population growth, migration, mortality and natality are discussed individually. The chapter is concluded by a description of the main differences in these elements and other socio-economic conditions as they exist in the less-developed and developed countries.

Characterization of Different Types of Biomass Wastes Using Thermogravimetric and ICP-MS Analyses

2020 ◽  
Vol 70 (12) ◽  
pp. 4594-4600
Keyword(s):  
Thermogravimetric Analysis ◽  
Food Industry ◽  
Wood Waste ◽  
Biomass Ash ◽  
Minor Elements ◽  
Ms Analysis ◽  
Icp Ms ◽  
Different Types

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG

Studies on the Behavior Some Paints in Electro-insulating Fluid Based on Vegetable Esters

2018 ◽  
Vol 69 (5) ◽  
pp. 1139-1144
Author(s):  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Livia Carmen Ungureanu ◽  
Valerica Stanoi ◽  
Traian Rus
Keyword(s):  
Structural Changes ◽  
Oxidation Processes ◽  
High Oleic ◽  
Painting Materials ◽  
Insulating Paper ◽  
Different Types ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Natural Ester

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.

scholarly journals Quality assessment of gas produced from different types of biomass pellets in gasification process

2019 ◽  
Vol 38 (2) ◽  
pp. 406-416 ◽  
Author(s):  
Marcel Mikeska ◽  
Jan Najser ◽  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar
Keyword(s):  
Gas Turbines ◽  
Combustion Engine ◽  
Calorific Value ◽  
Internal Combustion ◽  
Combustion Gas ◽  
Gas Cleaning ◽  
Gasification Process ◽  
Different Types ◽  
Before And After ◽  
Cleaning Technology

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.

scholarly journals The Importance of Diet in Predicting the Remission of Urticaria—Determination of Allergen-Specific IgE

Medicina ◽  
2021 ◽  
Vol 57 (7) ◽  
pp. 679
Author(s):  
Monica Iuliana Ungureanu ◽  
Liliana Sachelarie ◽  
Radu Ciorap ◽  
Bogdan Aurelian Stana ◽  
Irina Croitoru ◽  
...  
Keyword(s):  
Predictive Value ◽  
Allergic Diseases ◽  
Specific Ige ◽  
Egg White ◽  
Food Allergens ◽  
Pediatric Hospital ◽  
Disease Remission ◽  
Specific Serum ◽  
Different Types

Background and Objectives: Different types of food introduced gradually in the diet will expose children to different food allergens, increasing the chance of developing allergic diseases. The aim of our study was to determine if allergen-specific IgE values can influence, depending on the diet, the prediction of remission of urticaria in children. Materials and Methods: This prospective study was conducted in 132 patients diagnosed over two years with urticaria, admitted to “Sf. Maria” Clinical Pediatric Hospital Iaşi. Total IgE assay was performed by ELISA, and determination of specific serum IgE by the CLA System Quanti Scan method (Innogenetics, Heiden, Germany). Data were gathered and statistical analysis was performed using statistical software SPSS, using descriptive and inferential statistics. Results: The determination of specific IgE to food allergens was performed on a total of 132 cases. The values of specific IgE were positive for one or more food allergens in 84 patients (63.64%). The most common allergens involved were: cow’s milk in 33.3% cases, egg white in 22.6% cases, and hazelnuts in 11.9% cases. The specific IgE values for the different types of food included in our study had a predictive value for disease remission. Conclusions: The determination of specific IgE confirms the presence of a particular food allergen and may have predictive value for the future development of an allergic manifestation.

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