Behaviour of truck’s compressor’s connecting rods made of aluminium alloy under different manufacturing conditions

The main objective of this study was to explore quality increasing and cost reduction opportunities for a production of forged aluminium alloy 6082 connecting rods. These automotive parts are used for air compressors’ of the trucks. Connecting rods undergoes high cyclic loads during exploitation, therefore, the durability of this component is of a critical importance. The main factors characterizing high durability of the connecting rod are hardness and impact strength that may be achieved selecting the proper technology regimes. The main requirements for the aluminium alloy 6082 are hardness in the range of 90–120 HB and impact strength not less than 29.2 J/cm2. Furthermore, the main problem is a stability of testing results of randomly picked connecting rods as these parts are produced in big quantities for the export purposes. Our experiments and recommendations for the development of technology of connecting rods’ allowed maintaining the requirement in hardness, increasing the impact strength approximately twice and reducing the time needed for the production of one connecting rod as it let to save the cost of the part. First published online: 15 Jun 201

Cleaning of the surface contaminated by micro-particles by means of vibrations

This article is about vibration technologies adaptation for polluted surface cleaning. This cleaning method can be adapted in various areas [1-3]. For example, for used automotive air filters cleaning or during operation prolonging their life. Also this method can be used in buildings, because if in house is installed recuperator it is necessary to use air filters. During the exploitation this filters became polluted by contaminant particles. That to increase air filtering quality and prolonging filter life may be used vibration technologies

Modelling of Induction Heating of Steel Work Piece for Forging of Crankshaft

Vanadium microalloyed steel forgings provide high performance and cost effective solutions for automotive components in powertrain and chassis of modern cars and trucks. The majority of these forgings are produced from medium carbon steel with small additions of vanadium, manganese and sulphur to provide precipitation strengthening of the cooled ferrite-pearlite microstructure. This article deals with modelling of induction heating of steel billet prior to forging for automotive applications using COMSOL Multiphysics. The main aim of computer modelling was to evaluate the temperature distribution in billet since precise temperature control is required to prevent process-induced defects such as overheating or insufficient heating. Obtained numerical results for development of induction heating of steel billets have represented eventual increase of effectiveness by reducing of operation time.DOI: http://dx.doi.org/10.5755/j01.ms.24.3.18313</p

Vibrational method of cleaning of surfaces from homogeneous waste materials

Cleaning of contaminated surfaces is closely related to the study of adhesion forces between particles and the surface. Despite numerous technological advancements, the adhesion of particles and surfaces is a phenomenon that is far from being fully understood. This is due to many factors acting during process, - such as the surface roughness and material type, size, shape, electrostatic properties of particles, etc. A surface cleaning device based on nonlinear vibration of the contact element is presented in this paper. Relationships describing the periodic motion in steady state operating regimes are obtained. Characteristics of motion as functions of the frequency of excitation are investigated. Experimental investigations were performed for the determination of the influence of the cleaning velocity on the vibration frequency. It is shown that this dependence is directly related to adhesion forces between particles and the surface. Test results are in good accordance with theoretical predictions

Sedimentation Influence on Magnetorheological Brake Torque Moment

The aim of our research was to determine how sedimentation in magnetorheological fluid influences torque moment of a magnetorheological brake. Five different magnetorheological fluids (MRF-140CG, MRF-122EG, from Lord Corporation, USA, MRHCCS4-A and MRHCCS4-B are from Liquids Research Company, UK and MUDZH-3, made in A. V. Luikov Heat and Mass Transfer Institute, Belarus) were tested. The viscosity of these magnetorheological fluids in the magnetic field of 0–1 T was measured on Anton Paar Physica MCR-301 rheometer. We have selected the fluid with the best parameters to fill up our made magnetorheological brake. To determine sedimentation in magnetorheological fluid was used patent pending method by measuring fluids’ electrical resistivity. Electrical resistivity dependence on sedimentation mathematical model was created. Also four piezo-actuators were used to mix fluid inside the brake. Experimental setup to determine brakes’ torque moment was created.Исследуется влияние осаждения в магнитореологической жидкости на вязкое трение и крутящий момент магнитореологического тормоза. Протестировано пять различных магнитореологических жидкостей: MRF-140CG и MRF-122EG (корпорация Lord, США), MRHCCS4-A и MRHCCS4-B (компания Liquids, Великобритания) и MUDZH-3 (Ин-т тепло- и массообмена им. А. В. Лыкова НАН Беларуси). Вязкость магнитореологических жидкостей в магнитном поле интенсивностью 0 1 Т измеряли реометром типа Anton Paar Physica MCR-301. Для использования в магнитореологическом тормозе была выбрана жидкость с лучшими параметрами. Седиментацию в магнитореологической жидкости определяли запатентованным авторами методом, основанным на измерении электросопротивления жидкости. Разработана математическая модель вязкого трения и седиментации в зависимости от электросопротивления жидкости. Для смешивания жидкостей внутри магнитореологического тормоза использовали четыре пьезопривода. Создана экспериментальная установка для определения крутящего момента тормоза.Досліджується вплив осадження в магнітореологічній рідині на в язке тертя і крутний момент магнітореологічного гальма. Протестовано п ять різних магнітореологічних рідин: MRF-140CG i MRF-122EG (корпорація Lord, США), MRHCCS4-A і MRHCCS4-B (компанія Liquids, Великобританія) та MUDZH-3 (Ін-т тепло- та масообміну ім. О. В. Ликова НАН Білорусі). В язкість магнітореологічних рідин у магнітному полі інтенсивністю 0 1 Т вимірювали реометром типу Anton Paar Physica MCR-301. Для використання в магнітореологічному гальмі було вибрано рідину з кращими параметрами. Седиментацію в магнітореологічній рідині визначали запатентованим авторами методом, що базується на вимірюванні електроопору рідини. Розроблено математичну модель в'язкого тертя і седиментації в залежності від електроопору рідини. Для змішування рідин всередині магнітореологічного гальма використовували чотири п'єзоприводи. Розроблено експериментальну установку для визначення крутного моменту гальма

Suaugusiųjų mokymas aukštojo mokslo kaitos kontekste

Šiame straipsnyje aptariama, kaip suaugusiųjų švietimas, suvokiamas plačiąja prasme, jo misija ir vizija lemia aukštojo mokslo tikslus, uždavinius ir mokymo turinį. Jame teigiama, kad suaugusiųjų mokymo tikslai po truputį keičiasi, o ši kaita daro įtaką - tiesioginę arba ne - universitetams, jų intelektinių produktų pasiūlai. Suaugusiųjų mokymas turi lemiamą įtaką mokymo programų, jų turinio kaitai ir pateikimo būdų įvairovei. [...]

Investigation of Plastic Behavior of Alloyed Steel Deformed during Martensitic Transformation

We present the investigation of permanent strain of steel specimen occurred when metallurgical transformations take place even under small stress applied externally lower than the yield stress of material. Three alloyed steel grades were investigated: THG2000 (Uddeholm, Sweden), 40Kh13 and 95Kh18 (GOST, Russia). All steel grades differ in carbon content and amount of alloying elements and behave differently when transformation occurs. This intensively increased plasticity of steel specimen was observed during bending test when bending stress was just 100 MPa and was less than 10% of yield strength of the steel. The steel specimens were heated to 900–1050°C temperature and then bent during air quenching. Plastic deflections were observed though all cooling process that involved martensitic transformation as well. Different effect of compression and tensile stresses on microstructure evolution during martensitic transformation was determined by X-ray analysis as both types of stresses were formed in bent specimens.Исследованы пластические деформации, возникающие в стальных образцах вследствие микроструктурных трансформаций при воздействии внешних нагрузок, уровень которых может не достигать предела текучести материала. Рассматривались три легированные стали THG200 (производитель Уддехольм, Швеция), 40Х13 и 95Х18 (Россия) с разными легирующими элементами и процентным содержанием углерода, а также поведением при микроструктурных трансформациях. При генерировании изгибных напряжений порядка 100 МПа, не превышающих 10% предела текучести сталей, наблюдается возникновение пластических зон в стальных образцах, которые подвергались предварительному нагреву до 900 1050°С и последующему изгибу при закалке на воздухе. Пластические деформации возникали при реализации всех режимов охлаждения, которые сопровождались мартенситным превращением. С помощью рентгенографических исследований было выявлено разное влияние растягивающих и сжимающих изгибных напряжений на микроструктурные изменения при мартенситных превращениях.Досліджено пластичні деформації, що виникають у стальних зразках внаслідок мікроструктурних трансформацій при дії зовнішніх навантажень, рівень яких може не досягати границі плинності матеріалу. Розглядалися три леговані сталі ТHG200 (виробник Уддехольм, Швеція), 40Х13 та 95Х18 (Росія) з різними легованими елементами і процентним вмістом вуглецю та поведінкою при мікроструктурних трансформаціях. При генеруванні згинальних напружень порядку 100 МПа, що не перевищу є 10% границі плинності сталей, має місце виникнення пластичних зон у стальних зразках, які піддавали попередньому нагріванню до 900 1050°С і наступному згину при загартуванні на повітрі. Пластичні деформації виникали за реалізації всіх режимів охолодження, які супроводжувалися мартенситним перетворенням. За допомогою рентгенографічних досліджень виявлено різний вплив розтяжних і стискальних згинних напружень на мікроструктурні зміни при мартенситних перетвореннях

Vibrational method of cleaning of surfaces from homogeneous waste materials

Cleaning of contaminated surfaces is closely related to the study of adhesion forces between particles and the surface. Despite numerous technological advancements, the adhesion of particles and surfaces is a phenomenon that is far from being fully understood. This is due to many factors acting during process, - such as the surface roughness and material type, size, shape, electrostatic properties of particles, etc. A surface cleaning device based on nonlinear vibration of the contact element is presented in this paper. Relationships describing the periodic motion in steady state operating regimes are obtained. Characteristics of motion as functions of the frequency of excitation are investigated. Experimental investigations were performed for the determination of the influence of the cleaning velocity on the vibration frequency. It is shown that this dependence is directly related to adhesion forces between particles and the surface. Test results are in good accordance with theoretical predictionsKauno technologijos universitetasLietuvos mokslų akademijaSistemų analizės katedraVytauto Didžiojo universiteta

Investigation of a 1-DOF piezoelectric micro-positioning rotary stage

however, they can no longer satisfy continuously increasing new technical requirements, including (but not limited to) those for compactness, simple structures, high precision, and low manufacturing costs. A continuous study of a 1-DOF piezoelectric micro-positioning rotary stage, which was previously proposed by the authors and is characterised by the aforementioned criteria, is reported in this paper. The rotary stage is driven by the interaction between a cylinder-type piezoelectric transducer and a rotor, utilising resonant ultrasonic standingwave vibrations. The results demonstrate an acceptable correspondence between the detailed numerical and experimental harmonic and modal analyses of the piezoelectric cylinder. Investigations of the motion trajectories of the contact zones and driving tips in the XZ plane indicate the suitability of the selected operational vibration mode to provide a well-defined motion of the rotary stage. The average resolution of the rotary stage is determined to be 0.25 μrad and 0.26 μrad in the clockwise and anticlockwise direction, respectivelyKauno technologijos universitetasLietuvos mokslų akademijaSistemų analizės katedraVytauto Didžiojo universiteta