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See detailNumerical comparative study of five currently used implants for high tibial osteotomy: realistic loading including muscle forces versus simplified experimental loading
Diffo Kaze, Arnaud UL; Maas, Stefan UL; Kedziora, Slawomir UL et al

in Journal of Experimental Orthopaedics (2017), 5(28),

Background Many different fixation devices are used to maintain the correction angle after medial open wedge high tibial osteotomy (MOWHTO). Each device must provide at least sufficient mechanical ... [more ▼]

Background Many different fixation devices are used to maintain the correction angle after medial open wedge high tibial osteotomy (MOWHTO). Each device must provide at least sufficient mechanical stability to avoid loss of correction and unwanted fracture of the contralateral cortex until the bone heals. In the present study, the mechanical stability of following different implants was compared: the TomoFix small stature (sm), the TomoFix standard (std), the Contour Lock, the iBalance and the second generation PEEKPower. Simplified loading, usually consisting of a vertical load applied to the tibia plateau, is used for experimental testing of fixation devices and also in numerical studies. Therefore, this study additionally compared this simplified experimental loading with a more realistic loading that includes the muscle forces. Method Two types of finite element models, according to the considered loading, were created. The first type numerically simulated the static tests of MOWHTO implants performed in a previous experimental biomechanical study, by applying a vertical compressive load perpendicularly to the plateau of the osteotomized tibia. The second type included muscle forces in finite element models of the lower limb with osteotomized tibiae and simulated the stance phase of normal gait. Section forces in the models were determined and compared. Stresses in the implants and contralateral cortex, and micromovements of the osteotomy wedge, were calculated. Results For both loading types, the stresses in the implants were lower than the threshold values defined by the material strength. The stresses in the lateral cortex were smaller than the ultimate tensile strength of the cortical bone. The implants iBalance and Contour Lock allowed the smallest micromovements of the wedge, while the PEEKPower allowed the highest. There was a correlation between the micromovements of the wedge, obtained for the simplified loading of the tibia, and the more realistic loading of the lower limb at 15% of the gait cycle (Pearson’s value r = 0.982). Conclusions An axial compressive load applied perpendicularly to the tibia plateau, with a magnitude equal to the first peak value of the knee joint contact forces, corresponds quite well to a realistic loading of the tibia during the stance phase of normal gait (at 15% of the gait cycle and a knee flexion of about 22 degrees). However, this magnitude of the knee joint contact forces overloads the tibia compared to more realistic calculations, where the muscle forces are considered. The iBalance and Contour Lock implants provide higher rigidity to the bone-implant constructs compared to the TomoFix and the PEEKPower plates. [less ▲]

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See detailNEW METHODOLOGY FOR DESIGNING DIRECT-LASER-SINTERED MOTORCYCLE FRAME BASED ON COMBINATION OF TOPOLOGY OPTIMIZATION AND LATTICE IMPLEMENTATION
Cao, Thanh Binh UL; Kedziora, Slawomir UL

in International Journal of Mechanical Engineering (2017), 6(3), 39-50

The use of direct laser sintering (DLS) has become more attractive recently since it offers a promising tool in fabricating complex components rapidly. Particularly, the technique is seen more powerful ... [more ▼]

The use of direct laser sintering (DLS) has become more attractive recently since it offers a promising tool in fabricating complex components rapidly. Particularly, the technique is seen more powerful when it is combined with computer-aid design and computational optimization. In spite of knowledge increment in the above areas presently, design method for sophisticated structures towards DLS is still far from being fully exploited. Therefore, this paper was issued to investigate a novel methodology of design, developed by combining topology optimization and lattice-beam implementation, for a blend-solid-lattice frame of a motorcycle. From the obtained results, it was recognized that the as-built tubular hybrid structure demonstrated comparable values of first resonant frequency and mass with respected to those of the original. Additionally, it was found that stiffness of the generated structures depended strongly on locations where lattice was substituted. In particular, less stressed frame’s components were evidenced as appropriate regions for the substitution. The achieved results also revealed estimated buckling load factors, being circa 18 times higher than applied bumping loads acted on the tubular-lattice structure. Finally, equivalent stress predicted in static analyses confirmed all designs working safely in nominated conditions. Based on these achievements, it is believed that the new method worked quite acceptably in designing direct-laser-sintered motorcycle frame, and it is very promising to further develop the method as well as extend it into different complex direct-laser-sintered elements designed for future applications. [less ▲]

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See detailNew methodology for designing direct-laser-sintered motorcycle frame based on combination of topology optimization and lattice implementation
Cao, Thanh Binh UL; Kedziora, Slawomir UL

Scientific Conference (2017, February 07)

The use of direct laser sintering (DLS) has become more attractive recently since it offers a promising tool in fabricating complex components rapidly. Particularly, the technique is seen more powerful ... [more ▼]

The use of direct laser sintering (DLS) has become more attractive recently since it offers a promising tool in fabricating complex components rapidly. Particularly, the technique is seen more powerful when it is combined with computer-aid design and computational optimization. In spite of knowledge increment in the above areas presently, design method for sophisticated structures towards DLS is still far from being fully exploited. Therefore, this paper was issued to investigate a novel methodology of design, developed by combining topology optimization and lattice-beam implementation, for a blend-solid-lattice frame of a motorcycle. From the obtained results, it was recognized that the as-built tubular hybrid structure demonstrated comparable values of first resonant frequency and mass with respected to those of the original. Additionally, it was found that stiffness of the generated structures depended strongly on locations where lattice was substituted. In particular, less stressed frame’s components were evidenced as appropriate regions for the substitution. The achieved results also revealed estimated buckling load factors, being circa 17 times higher than applied bumping loads acted on the tubular-lattice structure. Finally, equivalent stress predicted in static analyses confirmed all designs working safely in nominated conditions. Based on these achievements, it is believed that the new method worked quite acceptably in designing direct-laser-sintered motorcycle frame, and it is very promising to further develop the method as well as extend it into different complex direct-laser-sintered elements designed for future applications. [less ▲]

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See detailUpAM: UPCYCLING VIA ADDITIVE MANUFACTURING – HOW 3D PRINTING CAN ENHANCE CIRCULAR ECONOMY
Wolf, Claude UL; Kedziora, Slawomir UL

in REVUE TECHNIQUE LUXEMBOURGEOISE (2017), 2017(2), 38

The University of Luxembourg developed the project upAM upcycling using Additive Manufacturing with the cooperation of FabLab Belval and Luxinnovation. This project was partially financed by Luxembourg ... [more ▼]

The University of Luxembourg developed the project upAM upcycling using Additive Manufacturing with the cooperation of FabLab Belval and Luxinnovation. This project was partially financed by Luxembourg National Research Fund Luxembourg (FNR). An alternative to a linear economy: extracting raw materials, producing, consuming, and discarding of a product, there is another option: Circular Economy (CE): reusing products, repairing, recycling, and upcycling. A concept of a system/process (upAM) is developed to reuse unwanted or un-functional polymers issued from existing products/ systems. Waste prints can be re-printed into new products or systems with the same / higher quality or value than products created from raw materials. The upAM project is, therefore, concentrating on upcycling according to the definition given by author” Upcycling is a process in which used materials are converted into something of a higher value and/or quality in their second life”. This definition is simple and reflects fully the meaning of the upcycling process. This idea is not new; the concept of reused materials/products giving them a new life has been present for hundreds of years as a countermeasure against the lack of raw materials. At the moment, the situation in developed countries is evolving. Society is more aware that unlimited consumption leads to unlimited production of waste. Therefore, collective consciousness of a circular economy occurs, which supports greater resources of productivity aiming to reduce waste and avoid pollution by design, and purposeful reused waste materials and unwanted products. Upcycling via additive manufacturing could be an important part of the circular economy (CE). Obviously, the CE and especially the upcycling process lead to reducing the usage of new raw materials, and it results in a reduction of energy usage, air and water pollution and even greenhouse gas emissions. The development of maker movement and democratisation of FDM technology is also strongly influencing the needs and benefits of the upcycling process. The project upAM is developed to increase this idea so that any individual can produce their products with a higher added value using recycled raw materials via the open technology of FDM 3D Printer. [less ▲]

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See detailOptimal design of cap screw thread runout for transversal and axial loads
Kedziora, Slawomir UL

in Journal of Applied Mechanical Engineering (2017), 6(1),

t The presented work is focused on a design of a new thread runout of screws and bolts subjected by transversal loads. These types of loads can occur in a normal service of bolt connection and they can ... [more ▼]

t The presented work is focused on a design of a new thread runout of screws and bolts subjected by transversal loads. These types of loads can occur in a normal service of bolt connection and they can lead to a failure. Two failure modes of the screw could occur: self-loosening of the screw or fatigue failure of the screw. The latter failure mode is analysed in the presented project focusing on an improvement of the existing design of the screws in terms of fatigue failure. The fatigue fracture of the screws, which are loaded by the transversal load, occurs normally in a groove of a first thread run of an engagement. A shape of the thread runout has some influence on stress in the thread therefore that shape can optimize to minimize the thread stress. Considering this, free shape optimisation was employed to find the best runout shape. As results of the presented work, the optimum design of the thread runout is proposed for the analysed conditions. The elaborated design of the cap screw brings significant improvement of the lifetime when the cycling tangential load occurs. In addition, the new design gives the better structural performance than the existing designs also for the cycling normal loads [less ▲]

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See detailDesign of Automotive Road Racing Rim with Aid of Topology Optimization
Martin, Laurent; Kedziora, Slawomir UL

Report (2016)

A goal of the project was done to develop a new good-looking racing rim of a sports car which would be lighter than existing ones. To achieve the goal, lightweight magnesium alloy Mg ZK60-T5 was applied ... [more ▼]

A goal of the project was done to develop a new good-looking racing rim of a sports car which would be lighter than existing ones. To achieve the goal, lightweight magnesium alloy Mg ZK60-T5 was applied for the rim, and its preliminary shape was developed employing topology op-timisation. The rim was designed for forging technology; this means that it had to have all manu-facturing features required by that production process. Based on a literature review, loads, boundary conditions and structural requirements were established, which are crucial for a further development process. The initial design was created using the topology optimisation, and then a parametric model was developed using a CAD system. As a next step, the first part of validation was done employing FEA in order to meet strength and stiffness targets; some modifications of the CAD model were imposed. As the last step, the final validation was done employing simply fatigue assessment. The optimisation and FEA were completed using Hyperworks 14/ Inspire 2015 software and the CAD model employing Autodesk Inventor 2015. The results show that the rim design meets theoretically all structural requirements and a good-looking shape was reached. The total mass of 7.9 kg of the designed rim is obtained, which means a reduction about 1.8 kg with the comparison with a reference rim. The 3D model and a technical drawing are completed; this means that the rim can be sent to a production phase. The results of the project also show that the topology optimisation technology provided by Hyperworks and the advanced CAD system can be used to generate competitive designs with any design offices without difficulties. [less ▲]

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See detailApplication of structural topology optimisation for planetary carrier design
Kedziora, Slawomir UL

in Kolakowski, Zbigniew (Ed.) SELECTED PROBLEMS OF CONTINUUM MECHANICS (2016)

A planetary gear train is very common in automatic gearboxes nowadays as well as in manual gearboxes for a low range or reduces. The main advantage of this gear train is compactness with a connection to a ... [more ▼]

A planetary gear train is very common in automatic gearboxes nowadays as well as in manual gearboxes for a low range or reduces. The main advantage of this gear train is compactness with a connection to a high possible gear ratio. Additional advantages such as a possibility to change of the gear ration and direction of rotation with a straightforward method by stopping one of three main components of the gear train can be found. Of course, the planetary gear train has disadvantages like a complex design that requires precise gears and a planet carrier with high torsional stiffness. The presented work concerns an essential part of the planetary gear train, namely, design of the planet carrier. An application of heavy-duty commercial gearboxes is selected because large torque levels dominate in this application and then the design of the carrier is crucial. One of the most important parameters of the plant carrier is its torsional stiffness, which has a direct influence on stress level gears. The low stiffness leads to uneven contact between the gears during loading, which reduces pitting resistance of the gears. The next important parameter is the stress level in the planet carrier, because of varying torque the planet carrier is exposed to fatigue failure. These two parameters are taken in the design process as the main factors. [less ▲]

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See detailAir centre structure of automotive heat exchangers in view of its post-buckling behaviour
Kedziora, Slawomir UL

in Mania, Radoslaw (Ed.) STATICS, DYNAMICS AND STABILITY OF STRUCTURES (2016)

Louvred air centres (fins) are thin-walled structures made of wrought aluminium alloy with a ratio between a minimum dimension and a thickness of 65 at least. The air centres are the critical components ... [more ▼]

Louvred air centres (fins) are thin-walled structures made of wrought aluminium alloy with a ratio between a minimum dimension and a thickness of 65 at least. The air centres are the critical components of automotive heat exchangers, taking into account heat transfer requirements and air pressure drop. In other words, their main goal is to provide a sufficient surface needed to transfer heat with a minimum pressure drop of an airside. Also, they create necessary structural support for heat exchanger tubes and thanks to them; the heat exchanger cores have a required structural resistance. [less ▲]

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See detailZastosowanie ANSYS i ANSYS Workbench w procesie projektowania obudów skrzyń biegów
Kedziora, Slawomir UL; Michalski, Przemysław

Scientific Conference (2013, April)

Streszczenie. Praca zawiera opis, wypracowanej przez firmę Eaton, metodyki obliczeń obudów skrzyń biegów zastosowaną w procesie konstruowania wyrobów. Dla lepszego zrozumienia zagadnienia omówione zostały ... [more ▼]

Streszczenie. Praca zawiera opis, wypracowanej przez firmę Eaton, metodyki obliczeń obudów skrzyń biegów zastosowaną w procesie konstruowania wyrobów. Dla lepszego zrozumienia zagadnienia omówione zostały cechy charakterystyczne korpusów wraz z szeregiem wymagań jakim muszą one sprostać (funkcjonalnym, technologicznym, kosztowym). Opracowany proces analizy został maksymalnie ujednolicony i ma zastosowanie zarówno dla przekładni wysokiej jak i niskiej obciążalności. Przedstawiono opracowane wymagania wytrzymałościowe jakie stawia się nowoczesnym konstrukcjom obudów skrzyń biegów, bazując na przeprowadzonych testach w pojazdach i naszym doświadczeniu. Zaprezentowano, jako docelowe rozwiązanie, spójną metodę analizowania obudów, które wykorzystują nowoczesne oprogramowanie metody elementów skończonych – ANSYS, ANSYS Workbench i zdobytą, w czasie testów i procesach walidacji wielu produktów, wiedzę. Model obliczeniowy został bardzo dobrze zweryfikowany, bazuje na wynikach laboratoryjnych badań zmęczeniowych, przeprowadzonych na rzeczywistych produktach, a także rezultatach prób drogowych w rzeczywistych pojazdach. Stworzona metodyka przyczynia się do znacznego skrócenia procesu konstruowania i weryfikacji konstrukcji, ograniczając do minimum konieczność testowania obudów. [less ▲]

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See detailHeat exchanger mounting bracket
Jamil, Ben Hamida; Kedziora, Slawomir UL; Frank, Leitch et al

Patent (2011)

The invention relates to a heat exchanger mounting bracket which has a first member with a retaining channel and a second member with a retaining lug. The retaining channel of the first member retains the ... [more ▼]

The invention relates to a heat exchanger mounting bracket which has a first member with a retaining channel and a second member with a retaining lug. The retaining channel of the first member retains the retaining lug of the second member at an initial mounting position, with a predetermined retaining force, by way of at least a formation on the first member. The retaining channel and lug are releaseable from one another when a force greater than or equal to the predetermined retaining force is applied between the first and second members. A heat exchanger mounting bracket is also provided where a body member is provided with a longitudinal slot toward one end for locating a portion (P) of a heat exchanger, and a pivotal arrangement toward the other end. The pivotal arrangement and longitudinal slot allow displacement of the portion (P) of the heat exchanger from a fore to an aft position upon application of an impact force. [less ▲]

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See detailDevelopment Process for a Charge Air Cooler to Meet Modern Requirements
Puillandre, Youen; Kedziora, Slawomir UL; Mailliet-Bestel, Damienne et al

in White, Peter (Ed.) Vehicle thermal management systems : VTMS 8 (2007)

Detailed reference viewed: 89 (1 UL)