<p class="Abstract"><span lang="EN-GB" style="mso-ansi-language: EN-GB;">The strut-type hybrid system can be made in different geometric shapes, which are affected by: the number and arrangement of struts, the shape and position of the cable in relation to the girder, and the size and shape of the cross-section of the girder. When choosing a system, all the listed parameters can vary geometrically, which has consequences on the behaviour of the girder when carrying the load by directly affecting the change in the stiffness of the system. In addition to the geometric parameters, the stiffness of the hybrid system is affected by variations in the properties of the incorporated materials and their mutual relations. In this paper, based on a detailed parametric analysis, the principles of design, the choice of materialisation, and the possibility of further optimisation of the persistent-type hybrid systems are given, with the aim of additionally increasing the load capacity and reducing the deformability. The results of this research are presented in the form of general expressions and diagrams, which can be applied with sufficient accuracy in practice when choosing the form and materialisation of the hybrid system, as well as the possibility of further optimisation of the system by applying pre-stressing. Using the example of external pre-stressing of a glued laminated timber girder, with the assumption of ensuring the lateral stability of the system, the results of the analysis of the behaviour of such a system under load in real conditions, i.e. the influence of the environment and changes in material properties, are given.</span></p>

Deployable lightweight structures are studied in the disciplines of architecture, civil engineering, aerospace engineering, mechanical engineering and other fields of their application. The research into these structures in individual fields resulted in a large amount of data sorted out by numerous classifications. The previously made classifications proposed by different authors are presented in this paper by the usage of reasonably unified tables that enabled a direct insight into the essential characteristics of these structures, their analysis and mutual comparison. One of the results of these analyses is the proposal for the unified classification given in a separate table in this paper. The results of interdisciplinary studies have been collected into a unified classification which could be applied for the research in different scientific fields, presenting the basic types of these structures, including individual elements and details with their characteristic features. The proposal of the unified classification of deployable structures is made according to the application of the basic elements used for structure forming. The suggested classification, with the review of the results of the present research, is a significant starting point for the scientists in different disciplines and it provides a detailed insight into the studied characteristics of these structures.

Deployable bar structures are made of lightweight materials, and that is one of the reason why they do not require high transportation costs, are easy to assemble (by unfolding) and disassemble (by folding) and are able to successfully respond to many requirements when in the shortest possible time it is necessary to provide architectural structures for various purposes. In this paper, the deployable bar structures are analyzed with the aim of forming a universal multifunctional space which could be used as a facility for temporary housing, healthcare, education and similar purposes. Due to the fact that geometric shape of a certain space significantly determines the function of that space, and the way it is used, detailed analyses of the geometric shapes of these structures have been conducted. Comparison of the forms explored so far with the existing architectural deployable bar structures has resulted in two distinct geometric forms: singly curved (barrel vault) and doubly curved (dome). It was concluded that the application of these forms in the form of freestanding modules provides limited opportunities for organizing functional content due to the specific locations of certain connections between elements, as well as the complicated design process. This is one of the reasons for rare application of these structures in architecture. The proposal of a multifunctional “Universal module 6” which consists of unified singly curved modules in combination with doubly curved and prismatic forms came as a result of the conducted analyses. Proposals for forming more complex architectural spaces of higher capacity provide a wider range of applications of these structures and opens new possibilities for their use.

. Constructive merging of “basic” systems of different behavior creates hybrid systems. In doing so, the structural elements are grouped according to the behavior in carrying the load into a geometric order that provides sufficient load and structure functionality and optimization of the material consumption. Applicable in all materializations and logical geometric forms is a transparent system suitable for the optimization of load-bearing structures. Research by individual authors gave insight into suitable system constellations from the aspect of load capacity and the approximate method of estimating the participation of partial stiffness within the rigidity of the hybrid system. The obtained terms will continue to be the basis for our own research of the influence of variable parameters on the behavior of hybrid systems formed of glued laminated girder and cable of different geometric shapes. Previous research has shown that by applying the strut-type hybrid systems can increase the load capacity and reduce the deformability of the free girder. The implemented parametric analysis points to the basic parameter in the behavior of these systems - the rigidity of individual elements and the overall stiffness of the system. The basic idea of pre-stressing is that, in the load system or individual load-bearing element, prior to application of the exploitation load, artificially challenge the forces that should optimize the final system behavior in the overall load. Pre-stressing is possible only if the supporting system or system’s element possess sufficient strength or stiffness, or reaction to the imposed forces of pre-stressing. In this paper will be presented own research of the relationship of partial stiffness of strut-type hybrid systems of different geometric forms. Conducted parametric analysis of hybrid systems with and without pre-stressing, and on the example of the glulam-steel strut-type hybrid system under realistic conditions of change in the moisture content of the wooden girder, resulted in accurate expressions and diagrams suitable for application in practice.

Hybrid systems, which were created by integrating the structural systems of different behavior in the transfer of loads, represent a new efficient system, with low self-weight, increased capacity characteristics and reduced deformability compared to the systems of which they are made of. Applicable to all materialization and logical geometric forms, they represent transparent systems suitable for optimization of structures. In this paper is represented the original analysis of parameters, reduced to relative values of a hybrid system with and without pre-stressing of different geometric shapes, particularly in terms of deformability. The results of the research are represented through the practical expressions and diagrams for use in practice, and on the basis of which can be determined suitable constellation of system from a simple girder, strut type hybrid system with different geometrical characteristics and pre-stressed hybrid system, and in the case of wood-steel hybrid system for different percentage of moisture of wood girder. To give access presents the accurate method that can be applied to any combination of materials in the context of a hybrid system.

Hybrid girders can be constructed in different geometrical forms and from different materials. Selection of beam’s effective constellation represents a complex process considering the variations of geometrical parameters, changes of built in material characteristics and their mutual relations, which has important effect on the behavior of the girder. This paper presents the theoretical and experimental research on behavior of the timber-steel hybrid girders’ different geometrical constellation with external prestressing and in different conditions of timber moisture. These researches are based on linear elastic analysis, and further refine by using the plasticity and damage models.