Tests to characterise the stiffness and strength of pultruded GFRP joints

4 Tests to characterise the stiffness and strength of pultruded GFRP joints 

In this sub-section consideration is given to some of the features of tests that have been carried out on axially loaded bolted and bonded joints. These joints arise predominantly in truss-type structures or in bracing systems used to resist sway of simply connected beam and column frame structures. 

The other type of bolted joint considered here is that used to connect beams to columns, and columns to colunm bases. These joints usually involve additional connection components in the form of angle or flat plate profiles. Consequently, both the bolts and the angles/plates participate in the transfer of bending moments and shear forces between beams and columns and between columns and their bases, and in the latter case also uplift forces. 

It is convenient to consider axially loaded joints first. Furthermore, as only minimal testing of such joints in compression has been reported (see Erki, 1995), consideration will be restricted to tension testing of such joints. 

The standardised pin bearing test methods specify the test fixture geometry, material specimen, pin and hole dimensions and their tolerances as well as details of the test procedure. Bearing compression failure is induced at the pin-hole contact interface within the composite material specimen by means of axial tension applied to the rig and specimen. A schematic diagram of the test set-up and test specimen is shown in Fig. 13.24(a). 

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