This research covers this gap by studying the failure mode of fixings in shear, when attached to different types of plasterboard with various properties. Also, the stiffening effect of the fixings is examined using different fixing diameters and the contribution of the head of the fixing is studied. The effect of composite action of light steel wall panels boarded with different types of plasterboard has also taken into account for out-of-plane loading simulating the wind pressure. A series of bending tests on 3.6 and 4.8m long walls using C sections to determine the composite action with boards was performed and was correlated with composite action theory.
The composite behaviour of fixings acting in shear between gypsum board and thin steel sections depends on the
effective properties of the board material in compression at the base of the fixing and the contribution of the head of
the fixing as it rotates. An elastic method is presented to determine the stiffness of the fixings, which uses the
effective elastic modulus of the gypsum board determined from a ?dowel? test in bearing based on the BS EN 383:2007
test. The deformation of the board in front of the fixing was determined by finite-element (FE) modelling as acting
over a constant strain zone of approximately 1·5 times the fixing diameter. A plastic method is also presented
to determine the shear resistance of fixings into gypsum board based on the compression resistance obtained
from a dowel test on the BS EN 383:2007 test. The theory is compared with the results of FE models using Abaqus for
3·5 mm dia. fixings into 12·5 mm thick gypsum board and with tests on fixings in shear and dowel tests; the
correlation is shown to be good. A small-scale push test is proposed to determine fixing properties in shear.