Mechanical behaviour modelling of a new anchor system for large diameter GFRP bars

The strong anisotropy of unidirectionally-reinforced FRP composites makes it difficult to design an efficient anchorage for measuring the tensile strength and this difficulty increases together with the cross section area of the specimen. To overcome this difficulty a new anchor system was developed for tension testing of large diameter GFRP bars in a universal testing machine. The anchor body designed and tested consists of two shells, pushed one against the other by the jaws of the testing machine, leaving an inner conical hole. The ends of the bar are provided with resin heads having the shape of the hole inside the anchor body. The present paper details the modelling investigation to verify and improve the shape and hence the performances of this anchor system. The approach adopted consists in a parametric numerical analysis that rests on the experimental data already gathered.