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Opis: This study analyses the many different parameters of the in-plane flexibility problem regarding the lateral behaviour of light timber-framed (LTF) wall elements with different types of sheathing material (FPB, OSB, or even reinforced concrete), as well as the thickness of the timber frame elements (internal or external wall elements). The analysis simultaneously considers bending, shear, and timber-to-framing connection flexibility, while assuming stiff-supported wall elements as prescribed by Eurocode 5. Particular emphasis is placed on the sliding deformation between sheathing boards and the timber frame, which can significantly reduce the overall stiffness of LTF wall elements. The influence of fastener spacing (s) on sliding deformation and overall stiffness is comprehensively analysed, as well as the different bending and shear behaviours of the various sheathing materials. The results show that reducing the fastener spacing can significantly improve the stiffness of OSB wall elements, while it is less critical for FPB elements used in mid-rise timber buildings. A comparison of external and internal wall elements revealed a minimal difference in racking stiffness (3.3%) for OSB and FPB specimens, highlighting their comparable performance. The inclusion of RC sheathing on one side of the LTF elements showed significant potential to improve torsional behaviour and in-plane racking stiffness, making it a viable solution for strengthening prefabricated multi-storey timber buildings. These findings provide valuable guidance for optimizing the design of LTF walls, ensuring improved structural performance and extended application possibilities in modern timber construction.
Ključne besede: timber, structures, light timber-framed element, modelling, numerical analysis
Objavljeno v DKUM: 17.03.2025; Ogledov: 0; Prenosov: 5
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Opis: The paper presents results of shear-bending experiments performed on panel shear walls used as load-carrying capacity walls in the construction of prefabricated timber structures. The aim of research is to determine the difference in resistance and ductility between panel shear walls, reinforced with two different methods. While the first, reinforcing with additional fiberboard, was not improve resistance and especially ductility in the contended sense, we tried to find a solution by inserting diagonal steel strips, which were fixed to the timber frame. Additionally, analytical solutions of those by mathematical modeling with the fictive thickness and height of fiber-plaster boards are proposed. Presented design models are simple and show a good coincidence with the measured results.
Ključne besede: timber structures, shear walls, shear bending tests, mathematical modelling
Objavljeno v DKUM: 01.06.2012; Ogledov: 3172; Prenosov: 41
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Opis: This paper provides an experimental analysis of timber-framed walls, coated with carbon fibre-reinforced polymers (CFRP) strengthened fibre-plaster boards, usually used as main bearing capacity elements in the construction of prefabricated timber structures. The tensile strength of the fibre-plaster boards is lower than the strength of timber frame, therefore it is convenient to strengthen boards with high-strength materials in order to gain a higher capacity. It has been shown that the inclusion of CFRP diagonal strip reinforcement on the load-carrying capacity can be quite high and that it is maximized when the carbon strips are connected to the timber frame. On the other hand, the ductility itself was not significantly improved. The test samples proved an important distinction in behaviour in timber frame-fibreboard connecting area, dependant on the boundary conditions between inserted CFRP strips and timber frame. It has been shown that proposed simplified Eurocode 5 methods, applicable for wood-based sheathing boards, could be unsuitable for the problems presented.
Ključne besede: civil engineering, timber structures, panel walls, fibre-plaster boards, steel reinforcement, carbon fibres
Objavljeno v DKUM: 01.06.2012; Ogledov: 2542; Prenosov: 101
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Opis: The paper provides semi-analytical modelling for prefabricated timber-framed walls using the modified ▫$/gamma$▫-method. The walls are composed of a timber frame and gypsum plasterboards (GPB) which are flexibly connected to the timber frame. Because the tensile strength of the GPB is approximately 10-times lower than the compressive one, it is convenient to strengthen the boards in their tensile diagonal direction with carbon fibre-reinforced polymer (CFRP) strips, which are glued to the boards. Additionally, in the proposed mathematical model the classical beam theory is used taking into account a fasteners' flexibility in the timber frame - GPB connecting area, as well as crack appearing in the GPB and an influence of the inserted CFRP strips. Therefore the CFRP strip contribution is considered with a modified slip modulus which results in the fictive increased stiffness coefficient of the fasteners.
Ključne besede: civil engineering, timber structures, frame walls, fibre-plaster boards, steel reinforcement, CFRP strips, carbon fibre-reinforced polymer, mathematical modelling
Objavljeno v DKUM: 01.06.2012; Ogledov: 2349; Prenosov: 32
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Opis: The paper presents the optimization of metal-plate-connected plane timber trusses with special emphasis on joint flexibility. The optimization was performed by the non-linear programming approach. Since various truss design parameters such as type of truss configuration, span/depth ratio, number and type of diagonal and vertical members and type of joint connections simultaneously affect each other, it is proposed that all of these parameters should be considered simultaneously in a single mathematical model. An optimization model for cost optimization of timber trusses was thus developed. The economic objective function for minimizing the structure's self-manufacturing costs was defined, subjected to the design, stress and deflection (in)equality constraints. The finite element equations were as the equality constraints defined for the calculation of the internal forces and the deflections of the structure. The stiffness matrix of the structure was composed by considering fictitiously decreased cross-section areas of all the flexibly connected elements. Constraints for the dimensioning of the timber members were determined in accordance with Eurocode 5 in order to satisfy the requirements of both the ultimate and the serviceability limit states. The cross-section dimensions and the number of fasteners were defined as independent optimization variables. A numerical example demonstrates the applicability of the optimization approach presented as well as the influence of the fasteners' flexibility on the optimal self-manufacturing costs.
Ključne besede: civil engineering, timber structures, trusses, fasteners, flexibility, optimization, non-linear programming
Objavljeno v DKUM: 01.06.2012; Ogledov: 2275; Prenosov: 126
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