Producción Grupo de Diseño Mecánico

Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/2850

Browse

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Natural vibration and instabilility of plane franmes: exact analitycal solutions using power series
    (2020-09-07) Martin, Héctor; Maggi, Norberto Claudio; Piovan, Tulio; De Rosa, M.A.; Martin, Nicolas
    The objective of this article is to introduce a practical procedure for determining analytical solutions to free vibration and instability problems related to plane frames, by means of extended power series method. Transfer conditions are applied in order to guarantee geometric continuity and simultaneous equilibrium of knots or conexions. This procedure leads to an important reduction in the number of unknowns to be handled. In the problem of eigenvalue calculation of a frame (both in dynamics or statics), the solution corresponds to the nullity of a determinant whose order is substantially smaller compared to the one found by other ways (e.g. finite element method). In order to attain better presición, other procedures require an increase in the quantity of unknowns, however in the case of power series, only the degree of power is increased without enlarging the number of unknowns. A number of examples are presented in order to show the advantages of the present procedure. Moreover comparisons of computational costs are included in the examples.
  • Thumbnail Image
    Item
    Variational method for non-conservative instability of a cantilever SWCNT in the presence of variable mass or crack
    (2020-04-14) De Rosa, M.A.; Lippiello, M.; Auciello, N.M.; Martin, Héctor; Piovan, Tulio
    In the present paper the non-conservative instability of a cantilever single- walled carbon nanotube (SWCNT) through nonlocal theory is investigated. The nanotube is modeled as clamped-free beam carrying a concentrated mass, located at a generic position, or in presence of a crack, and subjected to an axial load, at the free end. Nonlocal Euler-Bernoulli beam theory is used in the formulation and the governing equations of motion and the cor- responding boundary conditions are derived using an extendend Hamilton's variational principle. The governing equations are solved analitically. In or- der to show the sensitivity of the SWCNT to the values of an added mass, or crack and the in uence of the nonlocal parameter and nondimensional crack severity coe cient on the fundamental frequencies values, some nu- merical examples have been performed and discussed. Also, the validity and the accuracy of the proposed analysis have been con rmed by comparing the results with those obtained from the literature.