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Papers by Nicola Rizzi

Research paper thumbnail of Influenza del modello di trave sul comportamento post-critico dei telai piani

Research paper thumbnail of Continuum modelling of pantographic sheets for out-of-plane bifurcation and vibrational analysis

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2017

A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a co... more A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a coarse model of a plane network of beams which, in turn, is assumed as a model of a pantographic structure made up by two families of equispaced beams, superimposed and connected by pivots. The deformation measures of the beams of the network and that of the 2D body are introduced and the former are expressed in terms of the latter by making some kinematical assumptions. The expressions for the strain and kinetic energy densities of the network are then introduced and given in terms of the kinematic quantities of the 2D continuum. To account for the modelling abilities of the 2D continuum in the linear range, the eigenmode and eigenfrequencies of a given specimen are determined. The buckling and post-buckling behaviour of the same specimen, subjected to two different loading conditions are analysed as tests in the nonlinear range. The problems have been solved numerically by means of the C...

Research paper thumbnail of Coupled Instabilities in a Two-Bar Frame: A Qualitative Approach

Research paper thumbnail of Thin-Walled Beams with Open Cross-Section

Stability, Bifurcation and Postcritical Behaviour of Elastic Structures, 1991

Research paper thumbnail of La poutre élastique en plusieurs pièces

Presses Polytechniques et Universitaires Romandes, 2012

Research paper thumbnail of Symbolic manipulations in buckling and postbuckling anal- ysis

Research paper thumbnail of Tecniche di omogeneizzazione per l’analisi delle murature

Research paper thumbnail of Continuum models with microstructure for periodic brickwork arches and vaults

Research paper thumbnail of Masonry Modeled as Nonlinear Structured Continuum

Research paper thumbnail of Flexural-torsional behaviour of thin-walled frames

Research paper thumbnail of Applicazioni di un modello monodimensionale per lo studio della biforcazione di travi di spessore sottile

Research paper thumbnail of Continuum Models for out of Plane Behaviour of Masonry Panels

Research paper thumbnail of Un modello modnodimansionale per l'analisi della biforcazione flesso-torsionale di travi di spessore sottile

Research paper thumbnail of Buckling of thin-walled frames

We investigate the buckling of a ‘Roorda’ frame by means of a direct one-dimensional beam model. ... more We investigate the buckling of a ‘Roorda’ frame by means of a direct one-dimensional beam model. The frame is acted upon by a ‘dead’ load at the joint and is constrained there by an out-of-plane linear elastic spring. The possibility of warping constraints at the beam ends is also considered; the spring simulates the presence of braces in actual 3D frames. The numerical results are compared with those already obtained by the authors for an infinitely stiff spring.

Research paper thumbnail of One-dimensional continuum model of a modular lattice: identification of the constitutive functions for the contact and inertial actions

Research paper thumbnail of Modelli 2D con microstruttura per pannelli di muratura in 3D

Research paper thumbnail of Symmetric Bifurcation of Plane Frames through a Modified Potential Energy Approach

Journal of Structural Mechanics, 1980

The modified potential energy approach to the nonlinear analysis of slender elastic beams is empl... more The modified potential energy approach to the nonlinear analysis of slender elastic beams is employed to investigate the buckling and postbuckling behavior of two symmetric plane frames, namely a hinged portal frame and a hinged two-bar frame, The beams are assumed to be inextensible and shear undeformable. The “hybrid” functional on which the present analysis is based according to a

Research paper thumbnail of A 1D nonlinear TWB model accounting for in plane cross-section deformation

International Journal of Solids and Structures, 2016

Research paper thumbnail of A 1D nonlinear TWB model derived from an assembly of Koiter Shells

Research paper thumbnail of A 1D model for the nonlinear analysis of TWBs

Research paper thumbnail of Influenza del modello di trave sul comportamento post-critico dei telai piani

Research paper thumbnail of Continuum modelling of pantographic sheets for out-of-plane bifurcation and vibrational analysis

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2017

A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a co... more A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a coarse model of a plane network of beams which, in turn, is assumed as a model of a pantographic structure made up by two families of equispaced beams, superimposed and connected by pivots. The deformation measures of the beams of the network and that of the 2D body are introduced and the former are expressed in terms of the latter by making some kinematical assumptions. The expressions for the strain and kinetic energy densities of the network are then introduced and given in terms of the kinematic quantities of the 2D continuum. To account for the modelling abilities of the 2D continuum in the linear range, the eigenmode and eigenfrequencies of a given specimen are determined. The buckling and post-buckling behaviour of the same specimen, subjected to two different loading conditions are analysed as tests in the nonlinear range. The problems have been solved numerically by means of the C...

Research paper thumbnail of Coupled Instabilities in a Two-Bar Frame: A Qualitative Approach

Research paper thumbnail of Thin-Walled Beams with Open Cross-Section

Stability, Bifurcation and Postcritical Behaviour of Elastic Structures, 1991

Research paper thumbnail of La poutre élastique en plusieurs pièces

Presses Polytechniques et Universitaires Romandes, 2012

Research paper thumbnail of Symbolic manipulations in buckling and postbuckling anal- ysis

Research paper thumbnail of Tecniche di omogeneizzazione per l’analisi delle murature

Research paper thumbnail of Continuum models with microstructure for periodic brickwork arches and vaults

Research paper thumbnail of Masonry Modeled as Nonlinear Structured Continuum

Research paper thumbnail of Flexural-torsional behaviour of thin-walled frames

Research paper thumbnail of Applicazioni di un modello monodimensionale per lo studio della biforcazione di travi di spessore sottile

Research paper thumbnail of Continuum Models for out of Plane Behaviour of Masonry Panels

Research paper thumbnail of Un modello modnodimansionale per l'analisi della biforcazione flesso-torsionale di travi di spessore sottile

Research paper thumbnail of Buckling of thin-walled frames

We investigate the buckling of a ‘Roorda’ frame by means of a direct one-dimensional beam model. ... more We investigate the buckling of a ‘Roorda’ frame by means of a direct one-dimensional beam model. The frame is acted upon by a ‘dead’ load at the joint and is constrained there by an out-of-plane linear elastic spring. The possibility of warping constraints at the beam ends is also considered; the spring simulates the presence of braces in actual 3D frames. The numerical results are compared with those already obtained by the authors for an infinitely stiff spring.

Research paper thumbnail of One-dimensional continuum model of a modular lattice: identification of the constitutive functions for the contact and inertial actions

Research paper thumbnail of Modelli 2D con microstruttura per pannelli di muratura in 3D

Research paper thumbnail of Symmetric Bifurcation of Plane Frames through a Modified Potential Energy Approach

Journal of Structural Mechanics, 1980

The modified potential energy approach to the nonlinear analysis of slender elastic beams is empl... more The modified potential energy approach to the nonlinear analysis of slender elastic beams is employed to investigate the buckling and postbuckling behavior of two symmetric plane frames, namely a hinged portal frame and a hinged two-bar frame, The beams are assumed to be inextensible and shear undeformable. The “hybrid” functional on which the present analysis is based according to a

Research paper thumbnail of A 1D nonlinear TWB model accounting for in plane cross-section deformation

International Journal of Solids and Structures, 2016

Research paper thumbnail of A 1D nonlinear TWB model derived from an assembly of Koiter Shells

Research paper thumbnail of A 1D model for the nonlinear analysis of TWBs

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