Wydział Mechaniczny / Faculty of Mechanical Engineering / W1
Stały URI zbioruhttp://hdl.handle.net/11652/1
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Pozycja Postbuckling of delaminated thin-walled composite columns subjected to compression(Wydawnictwo Politechniki Łódzkiej, 2016) Gliszczyński, Adrian; Kubiak, TomaszSusceptibility to delamination is one of the major weaknesses of many advanced laminated composite structures. An integral element of research on composite structures is the analysis of the phenomenon accompanying with delamination formation. The sources of their formation should be already sought at the manufacturing stage when the delamination can occur due to the incorrectly selected autoclaving process parameters as well as their initiation can be initiated by the low velocity impacts , affecting also the local degradation of the stiffness of the material. Laminated fibre-reinforced composites made of high strength fibres in a relatively weak matrix material are susceptible to delamination (i.e. separation of the layers) . The physical quantities describing the initiation of delamination is the stress intensity factor or energy release fracture toughness. In comparison to the widely used isotropic materials i.e. steel or aluminium, the energy release rates of laminates are almost one hundred times smaller which confirms their relative propensity to delaminate .Pozycja Local Dynamic Buckling of C-Shape Profile Subjected to Bending(Wydawnictwo Politechniki Łódzkiej ; Katedra Dynamiki Maszyn - Wydział Mechaniczny Politechniki Łódzkiej, 2011) Urbaniak, Mariusz; Kubiak, TomaszThis paper deals with local dynamic buckling of thin-walled girder segments (short beam-columns) subjected to bending. Various shapes of pulse loading (triangle, trapezoid and rectangle) with a duration corresponding to the fundamental period of vibration were taken into account. Assumed boundary conditions correspond to a simple support, this agrees with conditions that exist in the place of the diaphragm in a long spar. The problem was solved by finite element method. In order to determine the critical load pulse amplitudes Volmir, Budiansky-Hutchinson, Ari-Gur and Simonetta criteria were employed.Pozycja Zbiór zadań z wytrzymałości materiałów. Cz. 2(Wydawnictwo Politechniki Łódzkiej, 2010) Gałkiewicz, Tadeusz; Królak, Marian; Kubiak, Tomasz; Red. nauk. Wydziału : Kapitaniak, Tomasz; Zielnica, Jerzy; Niezgodziński, TadeuszDruga część podręcznika ,,Zbiór zadań z wytrzymałości materiałów" jest kontynuacją części pierwszej wydanej przez Wydawnictwo Politechniki Łódzkiej pod koniec 2008 roku, w której zamieszczono zadania dotyczące prostych przypadków wytrzymałości materiałów (rozciąganie, ściskanie, zginanie i skręcanie). Część druga podręcznika przeznaczona jest dla studentów kierunków konstrukcyjnych i zawiera zadania z wytrzymałości złożonej, zbiorników cienkościennych, wyboczenia prętów, konstrukcji prętowych statycznie wyznaczalnych i niewyznaczalnych (belek, ram, łuków), płyt kołowych oraz innych wybranych zagadnień wytrzymałości materiałów. Rozdziały poprzedzone są krótkim wprowadzeniem zawierającym podstawowe wzory i definicje oraz metody i metodykę rozwiązywania zadań. Wiele zadań zostało rozwiązanych ze szczegółowym opisem rozwiązania. Autorzy uważają, że najefektywniejszą metodą nauczenia się poprawnego rozwiązywania zadań przez studentów jest samodzielne ich rozwiązanie. Dlatego też, podobnie jak w części pierwszej podręcznika, sporo zadań przeznaczonych jest do samodzielnego rozwiązania. Dla sprawdzenia poprawności rozwiązania tych zadań podano końcowe wyniki rozwiązania.Pozycja Advanced mechanical engineering : (with elements of numerical engineering analysis)(Wydawnictwo Politechniki Łódzkiej, 2006) Kotełko, Maria; Kubiak, Tomasz; Scientific Editor of the Division : Kapitaniak, Tomasz; Niezgoda, Tadeusz; Zielnica, Jerzy[...] The book is divided into three parts: the first one contains the foundations of mechanics of solids (particularly of the theory of elasticity) including the stress and strain analysis (concept of the stress and strain tensor in the rectangular co-ordinate system, as well as constitutive stress-strain relations for the general case of elastic anisotropic materials. The first part provides also a reader with a knowledge of yield criteria of not only ductile , isotropic material but also of modern orthotropic materials. The first part concludes with the energy methods in mechanics of materials. Although this part is devoted to advanced topics of mechanics of materials it contains as well some very basic problems (like the concept of equivalent stress for combined load) since they are not included into the syllabus of prerequisite subjects of Basic Mechanical Engineering I and II delivered to the students of Mechanical Engineering and Applied Computer Science (IFE), to whom the book is devoted mainly. The second part contains the theoretical foundations of the Finite Element Method, preceded with the description of the general concept of FEM and the short review of matrix algebra. Afterwards, the basic types of finite elements are discussed and their stiffness matrices are derived. The last part is devoted to selected advanced problems of mechanics of materials, including bending of thin plates, axi-symmetrical problems of the theory of elasticity and very basic introduction to the analyses of buckling of structural members. Each problem is discussed on the basis of analytical methods and simultaneously examples of numerical FE solutions are presented. In the section dealing with bending of rectangular plates the finite difference method is presented as an example of another, alternative numerical method that can be used in mechanics of materials. The third part concludes with the short chapter introducing a reader the problems of fatigue of structures. Some of the discussed topics are illustrated using exemplary problems with detailed solutions. However, the authors assume that a reader can find more of such problems in special text-books containing collections of problems of mechanics of materials to be solved.Pozycja Numerical Model of CAI Test for Fibre-Reinforced Polymer Plate.(Lodz University of Technology. Faculty of Mechanical Engineering. Department Division of Dynamics., 2016) Baszczyński, Piotr; Dziomdziora, Sebastian; Naze, Rafał; Kubiak, TomaszThis article presents numerical simulations of laminates subjected to Compression After Impact (CAI) testing including delamination modelling. Different model of impact damages of laminate were considered. Progressive damage analysis have been employed and different failure criteria have been applied. For each simulation failure load has been estimated as same as the position of damages at destroyed layer. Finally, obtained numerical results were compared with experimental data from referential paper.Pozycja Selected Problems of Determining Critical Loads in Sructures with Stable Post-Critical Behaviour.(Lodz University of Technology. Faculty of Mechanical Engineering. Department Division of Dynamics., 2016) Czapski, Paweł; Kubiak, TomaszThis paper presents selected cases of inapplicability of theory based methods of determining critical loads in thin – walled, composite tubes. 8th layered composite tubes with square cross-section were being subjected to static compression and in order to register experimental data two measuring equipment were employed: strain-gauges and Digital Image Correlation system ARAMIS R ⃝ . When measurement data were collected five different theory based methods were applied in order to determine critical loads. Cases where it was impossible to apply certain methods or some doubts about correctness of the results occurred were presented and analyzed. Moreover in cases where it was possible, the theory was equivalently transformed, in such a way to fit experimental data and calculate the critical loads.Pozycja Interactive buckling in thin-walled beam-columns with widthwise varying orthotropy.(Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej, 2006) Kubiak, TomaszAn analysis of local buckling of thin-walled beam-columns, taking account global precritical bending within the first order approximation, is presented in the paper. The problem of interactive buckling of the structure is solved by means of Byskov and Hutchinson's (1977) or Koiter's (1976) approximation theory. Beam-columns made from orthotropic plates with the main directions of orthotropy parallel to the wall edges characterised by a widthwise varying orthotropy coefficient ni=Eyi/Exi are investigated. Beam-columns with open sections (i.e. channel sections), simply supported on the loaded edges, are analysed. The girders are subjected to loads which cause a uniform or linearly variable shortening of the edges.Pozycja Dynamic response of thin-walled girders subjected to combined load(Politechnika Łódzka. Katedra Wytrzymałości Materiałów i Konstrukcji, 2012) Włuka, Piotr; Urbaniak, Mariusz; Kubiak, TomaszPozycja Stability of cross-ply composite plate with piezoelectronic actuators(Politechnika Łódzka. Katedra Wytrzymałości Materiałów i Konstrukcji, 2012) Włuka, Piotr; Kubiak, TomaszPozycja Dynamic buckling of thin-walled beam-columns with channel cross-section subjected to bending(Politechnika Łódzka. Katedra Wytrzymałości Materiałów i Konstrukcji., 2012) Urbaniak, Mariusz; Kubiak, Tomasz