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Stały URI dla kolekcjihttp://hdl.handle.net/11652/206

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1997 - 199912000 - 200922010 - 20184

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Teraz wyświetlane 1 - 7 z 7
  • Pozycja
    Wyboczenie cienkościennych konstrukcji kompozytowych z żebrami pośrednimi
    (Katedra Wytrzymałości Materiałów i Konstrukcji, Politechnika Łódzka, 2003) Teter, A.; Kołakowski, Z.; Kubiak, T.
    W pracy rozpatrzono interakcyjne wyboczenie pryzmatycznych, cienkościennych, kompozytowych słupów o przekrojach otwartych wzmocnionych żebrami pośrednimi i wzmocnieniami brzegowymi. Przyjęto, że słupy są swobodnie podparte. Nieliniowe zagadnienie rozwiązano asymptotyczną teorią Koitera w ramach pierwszego rzędu przybliżenia Asymptotyczna teoria pierwszego nieliniowego przybliżenia pozwala ocenić jednocześnie wpływ niedokładności i interakcji różnych postaci wyboczenia na zachowanie się konstrukcji cienkościennych. Ocena ta może stanowić jedynie dolne oszacowanie nośności. Szczegółowe obliczenia prowadzono dla kilku przypadków słupów.
  • Pozycja
    Influence of initial imperfections on the collapse behaviour of box-columns
    (Wydawnictwo Politechniki Łódzkiej, 1997) Grądzki, Ryszard
    In this work the analysis of the post-buckling state in the elasto-plastic range of a box-colunm subjected to uniform compression in the elasto-plastic range is preseoted. The problem is investigated using Rayleigh-Ritz variational method. The stress-strains relations in the plastic range are determined on the basis of the flow theory of plasticity. The proposed method is a combination of analytical and numerical solutions. Different materiał stress-strain curves and initial imperfections such: out-of-flatness and residual stresses are taken into account. The load-shortening curves for column of different geometrical parameters and material properties are shown in diagrams.
  • Pozycja
    The effects of compression loading on perforated TWCFS structural members of lipped channel cross-section
    (Wydział Mechaniczny. Katedra Wytrzymałości Materiałów i Konstrukcji Politechniki Łódzkiej, 2018) Macdonald, M.; Kulatunga, M.P.; Kotełko, M.
  • Pozycja
    Local Buckling of Thin-Walled Column of Square Cross-Section Made of In-Plane Coupled Laminate.
    (Lodz University of Technology. Faculty of Mechanical Engineering. Department Division of Dynamics., 2016) Kołakowski, Zbigniew; Teter, Andrzej; Pasierbiewicz, Damian
    The non–symmetric, general laminate exhibits different types of coupling between the extension, shearing, bending and twisting. For practical reasons, the in–plane coupled laminate is a particularly interesting. In this case, the coupling between shearing andextension takes place. Details calculations were performed for a short columns of square cross-section made of in–plane coupled and fully uncoupled laminate under uniform compression. Finite element method (FEM) and analytical–numerical method (ANM) were performed. In FEM analyses, the eigenbuckling problem has been solved using the Lanczos method, whereas the nonlinear buckling analysis were performed using the Newton– Raphson method and the Ritz method. In ANM analyses, the Koiter’s asymptotic theory is applied. The relationship between forces/moments and deformations/curvature were described using classical lamination theory (CLT). The coupling between in–plane shearing and extension has a significant influence on the behavior of thin–walled structures under compression.
  • Pozycja
    Comparision of Numerical Results with Known Solutions of Buckling Problem of Pressured Shallow Spherical Shells.
    (Lodz University of Technology. Faculty of Mechanical Engineering. Department Division of Dynamics., 2016) Lykhachova, Olga; Kołakowski, Zbigniew
    Buckling problem of pressured shallow spherical shells is studied numerically for two types of finite elements: axisymmetric and non–axisymmetric. A very good correspondence of obtained results and known solutions is revealed in the case of clamed and hinged spherical segments for both types of finite elements. The comparison of results also shows that using non–axisymmetric finite element lets one get full pre– and post–buckling equilibrium path in the range of relative deflections w=h.
  • Pozycja
    Elastic-plastic stability of FML columns of open cross-sections.
    (Wydział Mechaniczny. Katedra Wytrzymałości Materiałów i Konstrukcji. Politechnika Łódzka, 2015) Kowal-Michalska, K.; Kołakowski, Z.
  • Pozycja
    Static and dynamic interactive buckling of composite columns.
    (Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej, 2009) Kołakowski, Zbigniew
    The static and dynamic problem of interaction of global buckling modes in compressed columns with complex open and closed cross-sections was considered in the paper. The columns made of laminate composites were assumed to be simply supported at both loaded ends. A plate model was adopted in the analysis. The equations of motion of individual pla- tes (Schokker et al., 1996; Sridharan and Benito, 1984) were obtained from Hamilton’s Principle, taking into account all components of iner- tia forces (Teter and Kołakowski, 2005). Within the frame of the first order nonlinear approximation, the dynamic problem of modal interac- tive buckling was solved by the transition matrix using a perturbation method. Distortions of cross-sections and the shear-lag phenomenon were taken into consideration in the problem solution. A modification of the quasi-bifurcation dynamic Kleiber-Kotula-Saran criterion (Kleiber et al., 1987) was proposed. A comparison of the proposed modification to the Budiansky-Hutchinson criterion (Budiansky and Hutchinson, 1966; Hutchinson and Budiansky, 1966) was presented for a rectangular pulse loading.