Analysis of the stress and deformation distribution in the model of hip cemented arthroplasty after the treatment

W pracy przeprowadzono analizę rozkładu naprężeń i odkształceń w układzie biomechanicznym powstałym po zabiegu cementowej endoprotezoplastyki stawu biodrowego. W tym celu opracowano numeryczny model sztucznego stawu biodrowego. Metodą elementów skończonych (MES), przeprowadzono statyczną symulację wytrzymałościową układu implant-tkanka kostna w warunkach obciążeń odzwierciedlających początkową fazę podporową chodu. Uwzględniono zmianę właściwości mechanicznych cementu chirurgicznego na bazie PMMA po modyfikacji proszkiem ceramicznym.In this work it has been conducted the analysis of the stresses and deformation distribution in the biomechanical structure formed after surgery Hip Arthroplasty Cemented. For this purpose it has been developed a numerical model of an artificial hip joint. By means of finite element method (FEM), the static simulation of the implant-bone tissue structure, in the load conditions reflecting the incipient support gait, has been carried. It has been considered the change of the mechanical properties of the surgical cement based on the PMMA

Development and Calibration of The Mathematical Model of Traction Batteries for Electric Car

This paper presents the mathematical model of two types of batteries: VRLA (Valve Regulated Lead Acid) and lithium-ion batteries. The models allow for dynamic simulation of charging and discharging characteristics - determination of the output voltage for a wide range of currents and to determine the state of charge or discharge the battery, change the temperature of the cell volume and the number of cycles of use. The models were calibrated based on data from chassis dynamometer, which included the process of discharging the battery while driving at a constant speed and load from SOC = 0 to SOC=1 (SOC - state of charge), and based on manufacturer's data sheets.W niniejszej pracy przedstawiono model matematyczny dwóch typów akumulatorów: VRLA (ang. Valve Regulated Lead Acid) oraz litowo-jonowych. Opracowane modele pozwalają na dynamiczną symulację charakterystyk ładowania i rozładowania – wyznaczanie napięcia wyjściowego dla szerokiego zakresu prądów oraz określenie stanu naładowania lub rozładowania akumulatora, zmiany pojemności ogniwa od temperatury i liczby cykli użytkowania. Modele zostały wykalibrowane na podstawie danych pochodzących z hamowni podwoziowej, które obejmowały proces rozładowania akumulatorów w trakcie jazdy ze stałą prędkością oraz ładowanie od wartości SOC = 0 do SOC = 1 (SOC – stan naładowania, ang. state of charge), a także na podstawie danych katalogowych producenta

Well-to-wheel CO2 emission of electric vehicle in Polandlectric vehicle in Poland

The total CO2 emission of electric vehicle depends on a renewable energy share in an energy market of given country. At the moment, this share is significant only in a few European countries (Denmark, Germany, Scandinavian countries) having large number of water, solar and wind power plants. Additionally, France may be considered as a country possessing low-emission electric energy, because around 90% of this energy is generated by a nuclear power plants. In order to compare the greenhouse gas emission from an electric vehicle with combustion powered cars well-to-wheel (WtW) methodology may be applied. The well-to-wheel emission estimates the total CO2 which is required to generate a given power measured on vehicle wheels including generating, transferring and processing losses. The magnitude of WtW varies from 0g/km in the case of a vehicle charged directly by a solar or wind powered charging point to 200 g/km in the case of charging form public grid powered by old coal power plants. For the Polish energy market the share of renewable energy sources is negligible (below 10%), moreover majority of a power plants uses coal to generate electricity. However, according to the EU strategy this share should be doubled until 2020. Additionally, it is considered building of a nuclear power plant, which results in further reduction of CO2 from energetic industry. In this article WtW CO2 emission of electric driven vehicle charged from the public grid was analyzed for Polish conditions at present and various growth scenario as well. Moreover, an actual energy market structure as well as growth perspectives were reviewed

Application of green energy for EV battery charging station

The Well-to-Wheel (WtW) CO2 emission of the electric vehicle (EV) strictly depends on amount of a carbon dioxide (including transmission and conversion losses) required to produce an electric energy used to charge EV batteries. Value of the WtW emission may be lowered by increasing a share of low-pollutant power plants i.e. using renewable energy or nuclear power, however it needs a large financial investments and it is very long process, taking over a dozen years. Even in the case of countries having a large share of low-emission power plants (Germany), a smart grids must be applied in order to optimize a value of WtW CO2 emission. Usually batteries are charged during night, where energy demands are relatively low and at the same time wind turbines supplies majority of electric energy to the grid. Presented idea of the battery charging station described in this article has a local character. It uses photovoltaic panels as a source of "green" electric energy. As a consequence the value of WtW emission for an EV batteries charged in this station equals to 0 g/km. The charging station uses EV battery swap thus the time of staying in the station is shorter in comparison with normal or even fast charging. The battery swapping technology uses replacing of the discharged units mounted in EV by fully charged ones. The batteries are placed in special try, which enables a quick mechanical and electrical connecting and disconnecting. Moreover, batteries stored in the station may be used as an energy storage devices and makes charging process optimization easier; moreover, they can be used as an element of a smart grid system. The article describes model of charging station using both photovoltaic and quick EV battery swap

Influence of Anisotropy on the Viscoplastic Properties of a Hot Rolled Ti6Al4V Titanium Alloy

In this work, the influence of strain rate on the anisotropy of the Ti6Al4V titanium alloy has been analyzed. Tensile tests of notched specimens were carried out in three loading orientations (0°, 45°, and 90°) with respect to the rolling direction, using the servo-hydraulic testing machine and Hopkinson bar. Investigation was supported by the digital image correlation analysis of strain distribution on the specimen surface and assessment of the fracture mechanism. The Ti6Al4V titanium alloy reveals a typical strain rate hardening behavior; however, strain rate sensitivity is independent of the loading orientation. Increases of the loading orientation results in material softening, observed as lowered yield stress, whereas plastic strain exponent and modulus remain unaffected. Fracture strain decreases with loading orientation at quasi-static and dynamic loading conditions

Application of renewable energy sources in transport

Aim of the study was to analyze the influence of renewable energy sources on the well-to-wheel CO2 emission of the electric driven vehicle, especially with respect to the Polish electric energy supply structure. The main reasons of growing hybrid and electric powered vehicles share in the market are: limited fos sil fuels sources, narrow emission standards, global warming effect. Well-to-wheel analysis of CO2 emission is a very reliable methodology which enables to compare various types of vehicle powertrain and fuels. Overall CO2 emission of the electric vehicle depends mainly on share of the renewable energy sources (RES) in the market. Authors conclude that in Polish conditions, where RES share is negligible, overall CO2 emission of electric vehicle is comparable with combustion engine powered one

Investigations of mechanical properties of LH556 cast alloy and VP159 steel used for ballistic protection elements

Praca przedstawia charakterystyki naprężenie-odkształcenie stali austenitycznej VP159 oraz staliwa austenitycznego LH556, o dużej zawartości azotu, przy różnych prędkościach odkształcania. Do badań w zakresie obciążeń statycznych zastosowano serwohydrauliczną maszynę wytrzymałościową, natomiast w zakresie obciążeń dynamicznych metodę pręta Hopkinsona. Otrzymane rezultaty przedstawiono w formie wykresów naprężenia rzeczywistego w funkcji odkształcenia rzeczywistego. Na podstawie statycznej próby rozciągania wyznaczono również podstawowe parametry badanych materiałów, takie jak: E, R0,05, R0,2, Rm. Na podstawie badań stwierdzono, że stal VP159 ma znacznie lepszą ciągliwość niż staliwo LH556, natomiast pozostałe parametry i charakterystyki były zbliżone. Otrzymane wyniki można wykorzystać do wyznaczenia parametrów równań konstytutywnych opisujących termomechaniczne właściwości materiałów na potrzeby symulacji komputerowych.This work presents the stress-strain curves of the VP159 steel and LH556 cast alloy of high nitrogen content, at wide range of strain rates. At quasi-static deformation regime, the servohydraulic testing machine was applied, whereas for dynamic tests the Hopkinson bar was used. The results were presented as a true stress - true strain diagrams. The basic mechanical properties of materials, i.e., E, R0.05, R0.2, Rm were determined. The tests show that the VP159 steel exhibits a much better ductility than the LH556 cast alloy, whilst the other parameters were similar for both materials. The results create a base for determination of parameters appearing at different constitutive equations describing thermo-mechanical behavior of materials within finite element method codes

Properties and Structure of X30MnAlSi26-4-3 High Strength Steel Subjected to Dynamic Compression Processes

The paper presents the results of investigation on X30MnAlSi26-4-3 austenitic steel subjected to dynamic compression using the split Hopkinson pressure bar. The strain rate was 3700 s−1. The compression test was also carried out without the use of breaking rings and then true strain was about 0.3. The split Hopkinson pressure bar test take only few milliseconds to complete during which time it is impossible to transfer the excess heat out of the specimen, therefore the test must be carried out in adiabatic conditions and so the increase of the temperature caused by the work of plastic deformation had to be calculated. The stepping load method was used in order to evaluate the effect of adiabatic heating on the properties of steel which allowed to maintain the isothermal deformation conditions. The paper presents the comparison of results obtained during deformation under adiabatic and isothermal conditions in correlation to structure changes occurring in course of dynamic compression

Properties and Structure of X30MnAlSi26-4-3 High Strength Steel Subjected to Dynamic Compression Processes

The paper presents the results of investigation on X30MnAlSi26-4-3 austenitic steel subjected to dynamic compression using the split Hopkinson pressure bar. The strain rate was 3700 s−1. The compression test was also carried out without the use of breaking rings and then true strain was about 0.3. The split Hopkinson pressure bar test take only few milliseconds to complete during which time it is impossible to transfer the excess heat out of the specimen, therefore the test must be carried out in adiabatic conditions and so the increase of the temperature caused by the work of plastic deformation had to be calculated. The stepping load method was used in order to evaluate the effect of adiabatic heating on the properties of steel which allowed to maintain the isothermal deformation conditions. The paper presents the comparison of results obtained during deformation under adiabatic and isothermal conditions in correlation to structure changes occurring in course of dynamic compression