Numerical analysis of timber-framed wall elements coated with single fibre-plaster boards

摘要

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.