It is important to choose a suitable jointing method for the construction of FRP structure by jointing the parts of FRP. In this study, jointing was performed by means of adhesives. The selection of adhesives, the bonding condition and mechanical properties of bonded joint were examined using two types of substrates, FRP and SMC.
The effect of number of ply and adhesive pressure, interlaminar shear strength (ILSS), flexural strength and Izod impact strength of bonded beam were also studied. The results obtained are as follows.
(1) When non-bonding material is at or near the substrate surface, the surface preparation by sanding or cleaning causes the substrate failure and the bond strength becomes greater than the untreated one. On the contrary, when non-bonding material is with the substrate, it is necessary to choose the surface preparation method of substrate depending on the type of adhesives.
(2) Since the bond strength is greatly affected by the flexural rigidity of substrate, it seems to be necessary to refer to the flexural rigidity when the bond strength is compared.
(3) The strength and rigidity of bonded structure depend on the properties of substrate. In the case when the lateral load is worked on bonded structure, if suitable rigidity of substrate, adhesive pressure and number of ply for shearing force are chosen, the shearing failure does not occur on adhesive layer and the strength and rigidity of bonded structure does not decrease for flexural force.
(4) For impact, bonded structure is advantageous to unbonded one with respect to impact strength. Especially for the direction of impact, the strength of bonded structure remarkably increases if the volume of adhesives is increased.
