Over the last years, different methods, physical and mathematical, were used to find the optimal shape, minimizing the internal stresses, of shallow grid shells. As far as their original organic shape is concerned, the design of grid shell structures inspired architects and structural engineers in more than one way. Throughout history, the resolution of the problem related to the structural form-finding buried its roots on the activity of researchers and innovators. In the present paper an original approach for the form-finding is obtained by dynamic numerical simulation of hanging net, subjected to gravity load, over the time domain. In particular, the proposed method for the definition of the form is based on a multi-body rope approach (MRA) with masses connected by inextensible ropes characterized by a certain slack coefficient (sc) and by the degree of the constraint conditions. These parameters played a fundamental role in the definition of the shallowness ratio of the grid, and therefore in the effect of the instability of the reversed shape (grid shell) under loading. Moreover, in the case of shells with a very large number of nodes, a combined procedure based on non-uniform rational basis-splines (NURBS) formulation is proposed for the form-finding. Finally, step-by-step nonlinear analyses for the grid shells obtained by MRA were performed by a displacement control scheme, applying vertical incremental displacement to the nodes. Three circular grid shells were generated and analysed considering the effects of geometrical imperfections on the coupled instabilities varying the shallowness ratio.
Multi-Body Rope Approach for Grid Shells: Form-finding and Imperfection Sensitivity / Amedeo, Manuello. - In: ENGINEERING STRUCTURES. - ISSN 0141-0296. - ELETTRONICO. - 221:(2020), pp. 1-11. [10.1016/j.engstruct.2020.111029]
Multi-Body Rope Approach for Grid Shells: Form-finding and Imperfection Sensitivity
AMEDEO MANUELLO
2020
Abstract
Over the last years, different methods, physical and mathematical, were used to find the optimal shape, minimizing the internal stresses, of shallow grid shells. As far as their original organic shape is concerned, the design of grid shell structures inspired architects and structural engineers in more than one way. Throughout history, the resolution of the problem related to the structural form-finding buried its roots on the activity of researchers and innovators. In the present paper an original approach for the form-finding is obtained by dynamic numerical simulation of hanging net, subjected to gravity load, over the time domain. In particular, the proposed method for the definition of the form is based on a multi-body rope approach (MRA) with masses connected by inextensible ropes characterized by a certain slack coefficient (sc) and by the degree of the constraint conditions. These parameters played a fundamental role in the definition of the shallowness ratio of the grid, and therefore in the effect of the instability of the reversed shape (grid shell) under loading. Moreover, in the case of shells with a very large number of nodes, a combined procedure based on non-uniform rational basis-splines (NURBS) formulation is proposed for the form-finding. Finally, step-by-step nonlinear analyses for the grid shells obtained by MRA were performed by a displacement control scheme, applying vertical incremental displacement to the nodes. Three circular grid shells were generated and analysed considering the effects of geometrical imperfections on the coupled instabilities varying the shallowness ratio.File | Dimensione | Formato | |
---|---|---|---|
Engineering Struct 1-s2.0-S0141029620309895-main.pdf
non disponibili
Descrizione: Articolo principale
Tipologia:
2a Post-print versione editoriale / Version of Record
Licenza:
Non Pubblico - Accesso privato/ristretto
Dimensione
2.82 MB
Formato
Adobe PDF
|
2.82 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11583/2839343