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Showing papers in "International Journal of Space Structures in 1995"


Journal ArticleDOI
TL;DR: In spite of the spectacular development of reticulated shells, at least one problem has not yet been solved satisfactorily and that is the problem of buckling as mentioned in this paper, the instability of isolated members is st...
Abstract: In spite of spectacular development of reticulated shells, at least one problem has not yet been solved satisfactorily and that is the problem of buckling. The instability of isolated members is st...

112 citations


Journal ArticleDOI
TL;DR: In this paper, the spectrally formulated finite element analysis for vicsoelastically damped LSS is presented, and the proposed method is then extended to derive the dynamic response of a large truss structure using a computer program.
Abstract: Passive and active damping in a large space structure (LSS) is important in terms of performance under a dynamic load. Structural damping mostly arises as the result of many energy dissipation mechanisms acting in a system. The purpose of this paper is to present the spectrally formulated finite element analysis for vicsoelastically damped LSS. Using a fractional derivative model, the non-linear damping characteristics of a viscoelastic material have been modelled. The proposed method is then been extended to derive the dynamic response of a large truss structure using a computer program.

28 citations


Journal ArticleDOI
TL;DR: The existence of some geometrically imperfect members in a space truss is almost inevitable, and the fact that they produce initial internal member forces is undeniable as mentioned in this paper. But this paper is not about how...
Abstract: The existence of some geometrically imperfect members in a space truss is almost inevitable, and the fact that they produce initial internal member forces is undeniable. This paper is not about how...

26 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a concise overview of the main features of design and behaviour of reticulated spatial structures, and specifically double layer grids (DLGs) and single layer braced domes.
Abstract: The paper presents a concise overview of the main features of design and behaviour of reticulated spatial structures, and specifically double layer grids (DLGs) and single layer braced domes. Emphasis is laid on behavioural aspects which are peculiar to these structural systems and which require special attention in design. Some of these features: A susceptibility to progressive collapse; An important role played by joint rigidity, even in stiff systems like DLGs; Sensitivity to imperfections such as member lack of fit in DLGs, and geometrical distortions in shallow domes. Design strategies to deal with these problems and enhance structural efficiency are proposed.

19 citations


Journal ArticleDOI
TL;DR: The pseudo-force approach can be extended for non-linear analysis and to represent the member snap-through and dynamic jump due to inelastic member buckling/post buckling in a truss-type structure.
Abstract: The paper presents a systematic technique based on “pseudo-force” concept to determine dynamic response of truss structures during sudden progressive member failure. Emphasis has been given to the dynamic nature of the member failure and effects of such dynamic member failure on the overall structural behaviour. Responses of two-dimensional cantilever truss and a three-dimensional, corner supported, double-layer grid truss structure were investigated during sudden failure of some compressive members. In the method the sudden reduction in the load carrying capacity of a member is represented by external forces applied suddenly at the end joints of the member. Results obtained delineate the dynamic effects of member failure on joint displacements and member forces/stresses. In the present study the method is established for linear analysis. However, the pseudo-force approach can be extended for non-linear analysis and to represent the member snap-through and dynamic jump due to inelastic member buckling/post buckling in a truss-type structure.

15 citations


Journal ArticleDOI
TL;DR: The proposed structure is a parabolic deployable antenna consisting of radial planar pantograph masts deployed by long multi-segmented deployment cables, and intermediate cablenets, using the ‘active/passive substructure concept’.
Abstract: This paper introduces a new proposal in deployable structures using the ‘active/passive substructure concept’. The proposed structure is a parabolic deployable antenna consisting of radial planar p...

14 citations


Journal ArticleDOI
TL;DR: In this paper, a non-linear stability problem of imperfect reticulated shallow shells with distorted rectangular meshes is investigated and the fundamental governing equations are deduced by adopting an equivalent model and the principle of the virtual work.
Abstract: A non-linear stability problem of imperfect reticulated shallow shells with distorted rectangular meshes is investigated in this paper. The fundamental governing equations are deduced by adopting an equivalent model and the principle of the virtual work. For the reticulated shallow spherical shell under uniform vertical load, an axisymmetrical case is considered and the analytical solution of the coupled equations is given with the help of the asymptotical iteration method. Meanwhile, non-linear characteristic relations concerning load, deflection and imperfection factor are numerically analyzed. In particular, the corresponding solution degenerates to that of a reticulated circular plate when the radius of curvature of the structure R → ∞.

10 citations


Journal ArticleDOI
TL;DR: In its predeployed state, the SDSE is a collapsed structural element designed to achieve minimum volume configuration, which makes it beneficial for space applications as it can be folded and compactly stowed in a space transport vehicle.
Abstract: Over the past two decades there has been considerable need for reliable lightweight structures for various space applications, ranging from communication antennae to that of building the first spac...

9 citations


Journal ArticleDOI
TL;DR: In this article, a new approach for forming and erecting deployable metal domes is presented, where the whole structure is assembled initially at ground level in an essentially flat condition, by the use of appropriate post-tensioning, the space structure can be erected and shaped simultaneously.
Abstract: This paper presents a new approach for forming and erecting deployable metal domes. The approach is basically one where the whole structure is assembled initially at ground level in an essentially flat condition. By the use of appropriate post-tensioning, the space structure can be erected and shaped simultaneously. Based on previous studies on deployment principle and geometric models, this paper present an approach to investigate the appropriate way of post-tensioning for the shape formation and erection of the metal domes by means of finite element analyses. An example is given to illustrate the main steps in shape formation of the deployable metal domes, and the results of the example show that this new approach is reliable and feasible. Potentially, the procedure can offer economies over traditional methods of construction of such structures.

8 citations


Journal ArticleDOI
TL;DR: This paper addresses current solutions of light-weight retractable spatial structures – designed to enclose swimming pool facilities.
Abstract: Retractable spatial structures are modern buildings designed to comply with the user's flexibility needs – concerning the complete or partial opening of a building's enclosure. Most sport activitie...

6 citations


Journal ArticleDOI
TL;DR: The paper attempts the systematic classification and characterisation of prefabricated spatial frame systems in hierarchical order, descending from the geometric and static characteristics of the network down to technical details of member connection and construction techniques.
Abstract: Prefabricated spatial frame systems, such as double-layer grids and reticulated shells, differ greatly in their intended applications and technical features. The paper attempts the systematic class...

Journal ArticleDOI
TL;DR: Efficient algorithms are designed for substructuring and subdomaining for use in parallel computing, employing simple concepts of graph theory, while keeping the interface nodes to the smallest possible.
Abstract: In this paper efficient algorithms are designed for substructuring and subdomaining for use in parallel computing, employing simple concepts of graph theory. The algorithms developed partitions the graph model of a structure (or a finite element model) into subgraphs (subdomains) with equal or nearly equal number of internal nodes, while keeping the interface nodes to the smallest possible. Further refinement of the selected substructures (subdomains) are also made by recursive application of the algorithms. A simple algorithm is also presented for nodal ordering.

Journal ArticleDOI
TL;DR: In this paper, a summary of the characteristics of a large number of currently available commercial systems is presented in tabular form, corresponding to the hierarchical classification scheme presented in the second article in this issue.
Abstract: This article contains a summary of the characteristics of a large number of currently available commercial systems. The summary is presented in tabular form, corresponding to the hierarchical classification scheme presented in the second article in this issue. Features included in the summary table relate primarily to aspects of geometry, statical analysis and response, and assembly methods.

Journal ArticleDOI
TL;DR: In this article, the use of a flexible joint mechanism to enable a large reflector to be folded to a compact size and then deployed at geosynchronous orbit has been discussed, and the resonant frequencies of the jointed structure are shown to be similar to those of the non-jointed one but the amplitudes of vibration are significantly lower.
Abstract: Reflectors which are an integral part of space vehicles must be collapsed into the body of the vehicle for transportation to space. It is not efficient to store solid reflectors with a diameter greater than about 2.5 m in the launch vehicle and consequently deployable reflectors are used. This paper discusses the use of a flexible joint mechanism to enable a large reflector to be folded to a compact size and then deployed at geosynchronous orbit. The joint would be incorporated into the members of a skeletal truss structure and their effect on the dynamic behaviour of a single structural member and a large truss framework has been studied. It has been shown that the resonant behaviour of a structural member was significantly altered by introducing a joint into the system, but that of large trusses was not as seriously affected and resembled the equivalent of a non-jointed structure. The resonant frequencies of the jointed structure are shown to be similar to those of the non-jointed one but the amplitudes of vibration are significantly lower.

Journal ArticleDOI
TL;DR: An efficient method for optimum design of large skeletal and continuum structures, such as space structures, when the design variables are continuous or discrete, which is efficient in terms of the number of required structural analyses, as well as the overall computational cost of optimization.
Abstract: This study presents an efficient method for optimum design of large skeletal and continuum structures, such as space structures, when the design variables are continuous or discrete. Both sizing and shape design variables are considered. First the structural responses such as element forces are approximated in terms of some intermediate variables. By substituting these approximate relations into the original design problem, an explicit nonlinear approximate design task with high quality approximation is achieved. This problem with continuous variables, can be solved by means of numerical optimization techniques very efficiently, the results of which are then used for discrete variable optimization. Now, the approximate problem is converted into a sequence of second level approximation problems of separable form and each of which is solved by a dual strategy with discrete design variables. The approach is efficient in terms of the number of required structural analyses, as well as the overall computational cost of optimization. Examples are offered and compared with other methods to demonstrate the features of the proposed method.

Journal ArticleDOI
TL;DR: In this paper, the stability of plane, triangulated, uniformly compressed grids with rigid nodes is considered and the lowest critical loads for grids of hexagonal, triangular and rhombic overall layout are calculated for the case of in-plane buckling and associated modes are obtained.
Abstract: The stability of plane, triangulated, uniformly compressed grids with rigid nodes is considered. The lowest critical loads for grids of hexagonal, triangular and rhombic overall layout are calculated for the case of in-plane buckling and associated modes are obtained. The lower and upper bounds for these critical loads related to the behaviour of a single triangular cell are given. The connection between symmetry of the buckled configurations and the multiplicity of corresponding critical points is discussed and illustrated by the example of out-of-plane buckling of hexagonal grid.