scholarly journals Mechanical Behavior of Single-Layer Two-Way Grid Cylindrical Latticed Shell with Out-of-Plane Tension Members

2014 ◽  
Vol 8 (1) ◽  
pp. 311-319 ◽  
Author(s):  
Zhang Zhonghao ◽  
Ma Huihuan ◽  
Fujimoto Masumi ◽  
Fu Qiang
Keyword(s):  
Load Distribution ◽  
Single Layer ◽  
Distribution Patterns ◽  
Stability Behavior ◽  
Initial Imperfections ◽  
Tension Member ◽  
Grid Shell ◽  
Out Of Plane ◽  
New Type ◽  
Tension Members

Single layer two-way grid shell with in-plane and out-of-plane tension members is a new type of single-layer latticed shell roof. This study treats the effects of tension member installation on the buckling load and strength of a single layer two-way grid cylindrical shell roof by the numerical method. The tension members are installed to stiffen the rigidity of a single layer two-way grid shell roof and improve its stability behavior. Tension member installation and placement pattern is focused as both diagonal members of two-way grids and out-of-plane stiffened members in a cylindrical surface. The diagonal member and the out-of-plane member are used to increase the in-plane and the out-of-plane rigidity of a single layer two-way grid shell, respectively. The tension member placement pattern, the load distribution patterns, the initial imperfections and the initial axial force are considered for the numerical calculation parameters. It is confirmed by the numerical analysis that the tension members in out-of-plane and diagonals caused the increase in the buckling and strength of two-way grid shell.

Experimental Research on the Stability of Spatial Lattice Shell

2012 ◽  
Vol 204-208 ◽  
pp. 3048-3051
Author(s):  
Gan Tang ◽  
Wei Wei Li ◽  
Lin Feng Yin ◽  
Xiao Ming Guo
Keyword(s):  
Control System ◽  
Data Acquisition ◽  
Experimental Research ◽  
Single Layer ◽  
Data Acquisition System ◽  
Stability Behavior ◽  
Initial Imperfections ◽  
Spatial Lattice ◽  
The Stability ◽  
Lattice Shell

In the interest of an understanding to the imperfection stability behavior, a model of single layer spherical lattice shell was designed. The size and the pattern of initial imperfections were entirely measured. Automatic harmony loading control system and data acquisition system was used. The experiment plan, method and results have provided reference significance for the study on the stability of spatial lattice shell. The experimental results and the results of measured imperfections method were compared and analysed in detail. It is verified that measured imperfections method can accurately take into account of the effect of initial imperfections and it can be used for the supplementary checking computations of some important finished structures.

The Stability of Elliptic Paraboloid Grid Shell Lighting Roofs with Semi-Rigid Joints

2011 ◽  
Vol 374-377 ◽  
pp. 2148-2151 ◽  
Author(s):  
Ruo Qiang Feng ◽  
Bin Yao ◽  
Ji Hong Ye
Keyword(s):  
Bearing Capacity ◽  
Single Layer ◽  
Initial Imperfection ◽  
Parametric Modeling ◽  
Elliptic Paraboloid ◽  
Grid Shell ◽  
Steel Bars ◽  
New Type ◽  
The Stability ◽  
Rigid Joints

Grid shell is a new type of single layer latticed shell. Joint connections of this structrue always adopt semi-rigid joints: in-plane pin joints, out-plane rigid joints. A parametric modeling method using self-designed program is proposed in this paper. Bearing capacity of the elliptic paraboloid grid shell with semi-rigid joints is analyzed. Then, the influence of section of steel bars, rise-span ratio and initial imperfection on the bearing capacity is investigated.

Experimental study of the buckling strength of compression members connected to coplanar tension members

1989 ◽  
Vol 16 (3) ◽  
pp. 249-257 ◽  
Author(s):  
André Picard ◽  
Denis Beaulieu
Keyword(s):  
Experimental Study ◽  
Plane Deformation ◽  
Effective Length ◽  
Small Scale ◽  
Transverse Stiffness ◽  
Effective Length Factor ◽  
Tension Member ◽  
Compression Members ◽  
Out Of Plane ◽  
Tension Members

In structural systems using cross braces, the compression members are restrained against out-of-plane buckling by the tension members. It was shown in a theoretical study that the transverse stiffness provided by a tension member depends on the tension force in the member and on the flexural stiffness against out-of-plane deformation of the tension member. Equations were derived to determine the effective length factor of the compression member, taking into account the transverse stiffness of the tension member.This paper presents the results of a small-scale experimental study, which shows that the proposed equations slightly underestimate the transverse stiffness and overestimate the effective length factor. These equations are therefore conservative, but they indicate that an effective length factor much smaller than 1.0 can be used. Key words: stability, elastic buckling, elastic supports, cross braces.

Stability of cable-supported spherical reticulated shell with tension members

2020 ◽  
Vol 35 (3) ◽  
pp. 69-79
Author(s):  
Zhen Lu ◽  
Hui-jun Li ◽  
Chao Wang
Keyword(s):  
Carrying Capacity ◽  
Single Layer ◽  
Buckling Analysis ◽  
Load Carrying Capacity ◽  
Geometric Imperfection ◽  
Tension Member ◽  
Load Carrying ◽  
Initial Geometric Imperfection ◽  
Asymmetric Load ◽  
Tension Members

The suspendome has been widely employed in large-span space structures in recent years, and it has stronger structural stiffness and higher load-carrying capacity than single-layer spherical reticulated shell. In general, it is negligible for enhancement of load-carrying capacity to integrate cables and struts into the inner ring of reticulated shell. Based on the suspendome structure, a new hybrid space structure system, namely, cable-supported reticulated shell with tension member, is proposed in this study. To elucidate and verify its feasibility, the buckling mode and buckling form are obtained by the eigenvalue buckling analysis and nonlinear buckling analysis using ANSYS package, respectively. Furthermore, to determine the optimal structural form, this article investigates the effect of the main ribbed strut length, the initial geometric imperfection, asymmetric load, pretension in cables, and the material nonlinearity on its stability. The result shows that the proposed new structural system is of high load-carrying capacity. Tension member integrated to cable-supported reticulated shell can effectively improve the overall stiffness and greatly reduce the deformation of spherical reticulated shell. The plastic failure shape occurs with the similar pattern. The instable region mainly occurs on the main ribs with tension members, and each main rib only has one local failure dimple. The load-carrying capacity is remarkably affected by the asymmetric load, the initial geometric imperfection, and material nonlinearity. Based on the parametric analyses, Type C is the optimal choice, that is, appending cables and struts to the outermost ring of single-layer spherical reticulated shell, and arranging out-of-plane tension members under the four main ribs.

Analysis of Lowering Effects in Aluminum Single-Layer Latticed Dome with Temcor Joints

2016 ◽  
Vol 710 ◽  
pp. 390-395
Author(s):  
Shuai Xu ◽  
Zhi Hua Chen ◽  
Federico M. Mazzolani
Keyword(s):  
Load Distribution ◽  
Single Layer ◽  
Fe Model ◽  
Load Carrying Capacity ◽  
Load Bearing Capacity ◽  
Initial Imperfections ◽  
Load Carrying ◽  
Joint Behavior

The numerical analysis of a single-layer latticed dome has been carried out by using ANSYS, in order to evaluate the effect of influencing factors, like semi-rigidity of joint, buckling in compressed bars, load distribution and initial imperfections, which can produce important reductions of the load bearing capacity of these kind of structures. As a case study, the use of Temcor joint has been investigated. The characterization of the Temcor joint behavior to be introduced in the global model of the dome has been done by a FE model implemented on ABAQUS. The effects of the analyzed factors on the load-carrying capacity of the dome have been identified and useful suggestions for the design of this type of structures have been given.

Theoretical study of the buckling strength of compression members connected to coplanar tension members

1989 ◽  
Vol 16 (3) ◽  
pp. 239-248 ◽  
Author(s):  
André Picard ◽  
Denis Beaulieu
Keyword(s):  
Theoretical Study ◽  
Effective Length ◽  
Transverse Stiffness ◽  
Effective Length Factor ◽  
Axial Tension ◽  
Tension Member ◽  
Compression Members ◽  
Out Of Plane ◽  
Tension Members ◽  
Compression Member

In structural systems like diagonal cross-bracings, the out-of-plane deformation of the compression members is restrained by the tension members. The purpose of the theoretical study presented in this paper is to determine the transverse stiffness provided by the tension members and to evaluate the effect of this stiffness on the out-of-plane buckling of the compression members. Two practical cases are considered. The compression member is restrained against out-of-plane buckling by one tension member connected at midpoint or by two tension members connected at third points.The theoretical study shows that the transverse stiffness provided by the tension members does not have to be very large to obtain a significant decrease in the effective length factor. It is also shown that the transverse stiffness depends on the ratio of the axial compression force to the axial tension force and that the effective length factor increases with this ratio. However, even for large values of this ratio, the effective length factor is much smaller than 1.0. For instance, when the axial tension force is 0 and the ratio of the out-of-plane moment of inertia of the tension member to that of the compression member is 1.0, the effective length factor is approximately equal to 0.71 instead of 1.0 for both practical cases studied. Key words: stability, elastic buckling, elastic supports.

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

scholarly journals Cyclic tensile-compressive tests on thin concrete boundary elements with a single layer of reinforcement prone to out-of-plane instability

2017 ◽  
Vol 16 (2) ◽  
pp. 859-887 ◽  
Author(s):  
Angelica Rosso ◽  
Lisandro A. Jiménez-Roa ◽  
João Pacheco de Almeida ◽  
Aydee Patricia Guerrero Zuniga ◽  
Carlos A. Blandón ◽  
...  
Keyword(s):  
Single Layer ◽  
Boundary Elements ◽  
Out Of Plane ◽  
Compressive Tests
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