Influence of pattern anisotropy on the structural behaviour of free-edge single-layer gridshells

Abstract Free-edge gridshells represent the majority of built gridshells. Indeed, the gridshell reference geometry usually needs to be trimmed in order to provide building access or to insert the gridshell within an existing building, giving rise to one or more elastic boundaries. Despite the current design practice, so far a very limited number of scientific studies has been devoted to investigate the influence of elastic boundaries on the overall structural behaviour of gridshells. This paper focuses on the effects of the orientation of the boundary structure with respect to the grid direction. This is done by studying the buckling behaviour of an ideal single-layer steel gridshell, for different grid layout (quadrangular, hybrid, triangular) and orientation. The results of the parametric study demonstrate that the sensitivity of free-edge single-layer gridshells to the free-edge orientation strongly depends on the grid pattern. In particular, isotropic gridshells have shown an almost negligible influence of the free-edge orientation in terms of buckling load, in opposition to orthotropic gridshells. Moreover, the change in free-edge orientation induces significant variations of the global structural stiffness for all the layouts, resulting in possibly unacceptable displacements in service conditions.

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Grid patterns optimization for single-layer latticed domes

Advances in Structural Engineering ◽

10.1177/1369433220956813 ◽

2020 ◽

pp. 136943322095681

Author(s):

Masaki Teranishi ◽

Koichiro Ishikawa

Keyword(s):

Mechanical Properties ◽

Single Layer ◽

Objective Functions ◽

Imperfection Sensitivity ◽

Grid Pattern ◽

Geometric Imperfection ◽

Design Variables ◽

Geometrical Constraints ◽

Nodal Coordinates ◽

Superior Mechanical Properties

In previous studies on optimized single-layer latticed domes, the inner space and external shape of the optimized dome is different from those of the initial dome. This difference may result in loss of structural functionality and aesthetics intended by the designers, making it difficult to separately evaluate the mechanical properties of the grid patterns and shape of the surface. In this study, 64 types of single-layer latticed domes having different geometric properties are optimized to obtain mechanically effective grid patterns. Six types of objective functions are employed. The nodal coordinates of the domes serve as the design variables under geometrical constraints, where the nodes of the domes can be shifted on the surface area. The geometric and mechanical properties of the optimized grid patterns are evaluated quantitatively against the objective functions. Moreover, interactions between the geometric and mechanical properties are investigated. The results show that the optimized grid pattern has superior mechanical properties and geometric imperfection sensitivity. This optimization scheme can be applied for designing mechanically effective grid patterns for single-layer latticed domes.

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Seismic performance of single layer steel cylindrical lattice shells

Journal of Constructional Steel Research ◽

10.1016/j.jcsr.2019.105772 ◽

2019 ◽

Vol 163 ◽

pp. 105772 ◽

Cited By ~ 2

Author(s):

F. Cedrón ◽

A.Y. Elghazouli

Keyword(s):

Seismic Performance ◽

Single Layer ◽

Layer Steel ◽

Lattice Shells

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Vertical and Horizontal Seismic Response Analyses of Long-Span and Single-Layer Spherical Lattice Shell Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.602 ◽

2014 ◽

Vol 602-605 ◽

pp. 602-605

Author(s):

Jin Sheng He ◽

She Liang Wang

Keyword(s):

Vibration Control ◽

Shell Structure ◽

Response Spectrum ◽

Single Layer ◽

Internal Force ◽

Seismic Load ◽

Seismic Responses ◽

Long Span ◽

Current Design ◽

Lattice Shell

The dynamic characteristics of 80 m single-layer spherical lattice shell structure are analyzed to control its vibration under seismic load. Through the response spectrum curve of current design specification, the analyses for the vertical and horizontal seismic responses of the single-layer spherical lattice shell structure are made by CQC, and the displacement response of the nodes and internal force of the rods unit are calculated respectively. The calculation results show that the vertical and horizontal seismic responses of the long-span lattice shell structure are in great difference, and should be performed in vibration control at the same time, which could provide certain references for the seismic design and vibration control of single-layer spherical lattice shell structure.

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Lectotype Optimization of Single-Layer Steel Reticulated Dome Based on Sectional Optimization

2010 Third International Conference on Information and Computing ◽

10.1109/icic.2010.39 ◽

2010 ◽

Author(s):

Lu Xiaoyang ◽

Chen Shiying ◽

Guo Yuxia ◽

Zhao Xiaowei

Keyword(s):

Single Layer ◽

Layer Steel

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Geometrical Dimensional Effect on Natural Frequency of Single Layer Graphene in Armchair Configuration

Journal of Mechanical Engineering Research ◽

10.30564/jmer.v4i2.3831 ◽

2021 ◽

Vol 4 (2) ◽

Author(s):

Harshad Patel

Keyword(s):

Graphene Sheet ◽

Plate Theory ◽

Single Layer ◽

Free Edge ◽

Single Layer Graphene ◽

Geometrical Parameters ◽

Classical Plate Theory ◽

Element Analysis ◽

Nanomechanical Resonator ◽

Layer Graphene

Graphene has remarkable strength, such as yield strength and elasticconstant. The dynamic behaviour of graphene sheet is affected bygeometrical variation in atomic arrangement. This paper introducedgraphene with armchair atomic structure for estimating fundamental naturalfrequencies. The presented analysis can be useful for the possible highfrequency nanomechanical resonator systems. The analytical formulation,based on classical plate theory and continuum solid modelling based finiteelement method have been performed for estimation of fundamental naturalfrequencies of single layer graphene sheet (SGLS) with different boundaryconditions. The free edge and clamped edge boundary conditions have beenconsidered. For simplifying analytical formulations, Blevins approach fordynamic solution has been adopted and for validating analytical results.The finite element analysis of SLGS has been performed using ANSYSsoftware. The effect of variation in geometrical parameters in terms ofwidth and length of SLGS has been analysed for realization of ultra-highfrequency based nanomechanical resonator systems

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Penetration Behaviour of Steel Plates

Volume 5: 6th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A, B, and C ◽

10.1115/detc2007-35229 ◽

2007 ◽

Author(s):

M. H. Abdelshafy ◽

S. O. Oyadiji

Keyword(s):

Single Layer ◽

3D Models ◽

Penetration Resistance ◽

Residual Velocity ◽

Steel Target ◽

Multiple Layer ◽

Damping Material ◽

The Impact ◽

Layer Steel ◽

Penetration Behaviour

A finite element analysis using ABAQUS v6.6 has been performed to investigate the penetration behaviour of different target structures under the impact velocities of 1000 & 1200 m/s. The analysis has been performed to study the effect of the target configuration and the effect of introducing a damping material like rubber within the target structure on the penetration behaviour of these targets. Three dimensional (3D) models of targets consisting of various discrete one, two and three layers of hardened steel have been developed. The total thickness of each single or multiple layer steel target is 25 mm. These targets have been subjected to the impact of a projectile which was either blunt or had a hemispherical end and is made from a tungsten rod. Furthermore, 3D models consisting of layers of a damping material sandwiched between steel layers have also been developed and analysed. It is found that a purely steel target of multiple layers but of the same total thickness as a single layer steel target produced less residual velocity. This implies that the multiple layer steel targets produced more penetration resistance and, therefore, absorbed more of the impact energy than the single layer steel target. Similarly, multiple layer composite targets comprising layers of a damping material sandwiched between steel layers produced a greater penetration resistance and less residual velocity than a single layer steel target. However, the multiple layer composite targets only produced a slightly greater penetration resistance and less residual velocity than a multiple layer steel target.

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Vibration of structurally connected high-rise buildings under wind force

10.2749/ghent.2021.1598 ◽

2021 ◽

Author(s):

Mehmet Köhserli ◽

Péter L. Várkonyi

Keyword(s):

Structural Systems ◽

Building Structures ◽

Structural Behaviour ◽

Wind Force ◽

Building Stock ◽

Existing Building ◽

High Rise ◽

Tall Structures ◽

Simulation Results ◽

Structural Networks

<p>Cities are organized around various underlying networks but building structures do not follow this trend. The isolation of structural systems causes difficulties in the case of tall structures. We investigate the possibility of improving structural behaviour by organizing buildings into urban-scale structural networks, with focus on vortex-induced vibration. We review our recent work, in which randomly generated collections of high-rise buildings were examined by numerical simulation using a conceptual model of the network composed of springs and point masses. Here we examine the behaviour of a realistic collection of buildings, generated by considering the existing building stock and urban fabric of Midtown Manhattan. The new simulation results suggest that connections among the buildings would enable the application of significantly softer bracing systems. This finding suggests that urban-scale structural networks is a promising direction of urban development.</p>

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Performance of Single Layer Steel Barrel Vault Under Buckling

International Journal of Scientific Research ◽

10.15373/22778179/march2014/149 ◽

2012 ◽

Vol 3 (3) ◽

pp. 392-396

Author(s):

MULESH K. PATHAK ◽

Keyword(s):

Single Layer ◽

Layer Steel

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Structural Behaviour of Single Layer Space Frame with Member Arrangement Following Spiral Phyllotaxis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.842.505 ◽

2013 ◽

Vol 842 ◽

pp. 505-511

Author(s):

Kok Keong Choong ◽

Jae Yeol Kim

Keyword(s):

Single Layer ◽

Plant Structure ◽

Structural Behaviour ◽

Space Frame ◽

Physical Constraints ◽

Finite Element Software ◽

Space Frames ◽

Structural Space ◽

Regular Arrangement ◽

Frame System

The regular arrangement of the plant organs is botanically known as phyllotaxis. Among the types of phyllotaxis found in nature, spiral phyllotaxis is the most frequently found pattern. The unique arrangement of this pattern in plants has benefited most of the plant structure as it enables them to grow more efficiently and compatible for physical constraints such as moisture and amount of light falls. In this research, the unique spiral phyllotaxis pattern has been adopted as idea for member arrangement pattern for structural space frame system. Two type of spiral phyllotaxis pattern and one regular model are generated. Analysis using finite element software LUSAS has been carried out in order to determine the effect of member arrangement following spiral phyllotaxis on stresses and displacement in the space frames.

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