A parametric study on geometrically nonlinear behavior of curved beams with single and double link rods, and supported on moving boundary

In this paper, the behavior of a single degree-of-freedom (SDOF) passive vibration isolation system with geometrically nonlinear damping is investigated, and its displacement and force transmissibilities are compared with that of a linear system. The nonlinear system is composed of a linear spring and a linear viscous damper which are connected to a mass so that the damper is perpendicular to the spring. The system is excited by a harmonic force applied to the mass or a displacement of the base in the direction of the spring. The transmissibilities of the nonlinear isolation system are calculated using analytical expressions for small amplitudes of excitation and by using numerical simulations for high amplitude of excitation. When excited with a harmonic force, the forces transmitted through the spring and the damper are analyzed separately by decomposing the forces in terms of their harmonics. This enables the effects of these elements to be studied and to determine how they contribute individually to the nonlinear behavior of the system as a whole. For single frequency excitation, it is shown that the nonlinear damper causes distortion of the velocity of the suspended mass by generating higher harmonic components, and this combines with the time-varying nature of the damping in the system to severely distort the force transmitted though the damper. The distortion of the force transmitted through the spring is much smaller than that through the damper.

Download Full-text

Influence of creep on the geometrically nonlinear behavior of soft core sandwich panels

International Journal of Mechanical Sciences ◽

10.1016/j.ijmecsci.2015.11.025 ◽

2016 ◽

Vol 105 ◽

pp. 398-407 ◽

Cited By ~ 3

Author(s):

Ehab Hamed ◽

Yeoshua Frostig

Keyword(s):

Sandwich Panels ◽

Nonlinear Behavior ◽

Soft Core ◽

Geometrically Nonlinear

Download Full-text

Parametric Study of the Elementary Segment of an Antiprismatic Pop-Up Deployable Lattice Column

YBL Journal of Built Environment ◽

10.1515/jbe-2014-0011 ◽

2014 ◽

Vol 2 (2) ◽

pp. 65-86

Author(s):

Noémi Friedman ◽

György Farkas ◽

Adnan Ibrahimbegovic

Keyword(s):

Parametric Study ◽

Complex Structure ◽

Basic Element ◽

Element Formulation ◽

Geometrically Nonlinear ◽

Preliminary Design ◽

Elementary Segment ◽

Basic Segment ◽

Force Displacement ◽

Displacement Diagram

Abstract In this article the primary segment of an antiprismatic pop-up mast is analyzed, that can be applied for largely flexible architectural designs, like deployable bridges or transportable look-out towers. This deployable column, consisting of rigid plates, rigid and elastic bars, is characterized by its selfdeploying behavior due to the energy accumulated from lengthening the elastic bars during packing. The main goal of this paper is to prepare the analysis of the complex structure by a herein detailed investigation of the behavior of one, basic element of the deployable mast. After the analytical examination of the general behavior of the basic segment a geometrically nonlinear finite element formulation is used to trace the force-displacement diagram. Besides the parametric study, approximations of main mechanical parameters are herein given for facilitating preliminary design of such deployable structures.

Download Full-text