This paper provides an experimental analysis of timber-framed walls, coated with single fibre–plaster coating boards fastened to a timber frame. As the walls under a horizontal load actually behave ...like a deep composite beam Faherty KF, Williamson TG, Wood engineering and construction handbook, McGraw-Hill Publishing Company; 1989; Premrov M, Dobrila P. Modelling of fastener flexibility in CFRP strengthened timber-framed walls using modified γ – method. Eng Struct 2007; 30(2): 368–75; Dobrila P, Premrov M. Reinforcing methods for composite timber frame-fibreboard wall panels. Eng Struct 2003; 25(11): 1369–76, a fasteners’ disposition is very important and directly influences bearing capacity as well as stiffness of a wall. The presentation, based on the measured results, ascertains that fasteners’ spacing has a remarkable influence on behaviour of the treated walls in many aspects. Additionally, for designer purpose, comparison with relative expensive strengthening solution by using CFRP diagonal strips Premrov M, Dobrila P, Bedenik BS. Analysis of timber-framed walls coated with CFRP strips strengthened fibre-plaster boards. Int J Solids Struct 2004; 41(24): 7035–48 is made and gives some interesting indications for designing practice by multi-storey timber-framed buildings.
► We present a numerical analysis of panel walls with openings coated with FPB. ► The research deals the full elements and the elements containing an opening. ► The numerical results proved a good ...coincidence with the experimental results. ► The impact of elements with openings on the resistance of wall systems is analysed. ► The elastic resistance and the ductility of the wall system are improved.
The paper presents a numerical analysis of the horizontal load-bearing resistance of timber framed wall elements coated with single fibre plaster boards (FPBs) that can be used in the construction of single- or multi-storey prefabricated buildings. The research deals with both the full elements (without any opening) and with elements containing an opening. The study represents a continuation of the experimental research realised in the past period.
The horizontal load-bearing capacity of FPB-sheathed timber-frame wall elements is mainly dependent on the relatively low tensile resistance and the consequent occurence of cracks in FPB. In the numerical model, the brittle behaviour of the FPB under tensile stresses is proposed to be modelled by using shell elements that allow for nonlinear material behaviour. The results of the numerical analyses proved good coincidence with the results of the experimental tests. Further, the possible impact of the wall elements with openings on the load-bearing capacity of wall systems subjected to horizontal (wind and especially earthquake) loads is discussed. A comparative study has shown that the influence may be considerable. By overtaking a part of the load these elements improve the structure’s elastic resistance, while in the post-elastic phase they provide additional ductility. Also, the over-strength and the ultimate capacity of the wall system are improved. In terms of structural safety, therefore, the elements with openings have a beneficial effect during moderate earthquakes, but also in the case of a severe earthquake. It was concluded that the methods currently available in the European design codes underestimate the capacity of wall elements with openings. This may result in inadequate modelling of structural behaviour and indicates the need for more accurate methods.
This paper provides a numerical analysis of sheathing boards influence on racking resistance of timber-frame walls coated with single sheathing boards fastened to a timber frame. Worldwide, the walls ...are usually broadly used as main bearing capacity vertical elements in prefabricated residential timber buildings. Designers or producers usually face the important dilemma of using the best sheathing board with regard to the height and location of a building. The presented research thus aims at comparing the results obtained through calculations made on test samples covered with either fibre-plaster or wood-based sheathing boards. Therefore, the presented conclusions, supported by the measured results, propose some important indications in behaviour of the timber-framed wall elements under a horizontal load covered with different sheathing boards and present some useful recommendations in designing of tall timber-framed buildings located on heavy windy or seismic area.
This paper presents an experimental analysis of timber-framed wall elements with openings, coated with single fibre-plaster boards (FPB) fastened to a timber frame. The aim of the study presented ...here was to provide the information about the influence of the openings on the wall’s racking load-carrying capacity as well as on the horizontal stiffness of the timber-framed wall element. The tests were carried out on three groups of full-scale wall panels with different areas of openings. The measured results were compared to the results of wall panels without openings (having the same dimensions and material properties) obtained from the previous research work. Subsequently, the strength/stiffness ratios, defined as the ratios of strength/stiffness of wall panels with openings to those of no-opening wall panels, were calculated. Finally, the obtained results were compared to two analytical procedures from the literature, namely the equations proposed by Yasumura and Sugiyama and by the Method B from Eurocode 5. The comparison shows that the present results are more comparable to the former procedure, while the later one in general gives higher values of strength/stiffness ratios. The presented experimental study also emphasizes the conclusion that the timber-framed wall elements containing an opening may be accounted to contribute to the overall horizontal load-carrying capacity, especially when a considerable part of the structure is made of such panels.
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.
This paper provides approximate analytical solutions for diagonally reinforced timber-framed panel walls usually used as main bearing capacity elements in the construction of prefabricated timber ...structures. These walls can be mathematically treated as composite elements made of a timber frame and fibre-plaster boards as a coating material. As boards are the weakest part of the system they are reinforced with steel diagonals. The proposed approximate analytical models with the fictitious thickness and width of fibre-plaster boards enable simultaneously to consider the influence of inserted steel diagonals, flexibility of mechanical fasteners between the boards and the timber frame and any appearing cracks in the tensile area of the fibre-plaster boards. The obtained numerical results show good agreement with the measured experimental results.
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