Title: Efect of the Surface Preparation on PP Reinforced Glass FiberAdhesive Lap Joints StrengthAbstract:This article is concerned with the infuence of surface treatment on thestrength of single lap joints. The tensile tests were carried out in order to fnd thesurfacetreatmentswhichmaximizejointstrengthusingpolypropylenereinforcedglass fber as adherents. Themaximumshear strengthwas obtainedwiththetrichlorethylene plus primer treatment when using a cyanoacrylate adhesive. Thepretreatment efectiveness was evaluated in terms of environmental durability andan important decrease in static strength of adhesive joints occurred when they wereimmersed in water.ntroduction: Single lap joint is the simplest to manufacture however this confgurationis the wea!est "#$. Therefore these joints are essentially used for lightlyloaded applications. The loading eccentricity promotes a rotation of thejoint and as a result peel stresses occur. Such stresses are very important inthe failure process. %n this case it is very important to minimize peel stresseswhich can be reduced by an ideal superposition length "&'($ tapering of theadherents ")'*$ adherent thic!ness "&+'##$ adhesive thic!ness "+#&$adherent strength and elastic modulus "#,###-$ adhesive strength andelastic modulus "($.