Study On Connection Performance Of Adhesive Bonded Joints For Gfrp And Stainless Steel

With the development of modern industrial technology,fiber reinforced composites are widely used in various industrial fields because of their high tensile strength,low density,low weight,good corrosion resistance and excellent fatigue resistance.In some structural applications,fiber reinforced composites have replaced or been used in conjunction with metal materials.When the fiber reinforced composites are connected with metal materials,the connection zone is often weak,so the design of the connection between the two is the key problem.At present,composite materials and metal materials are commonly used to join the main mechanical connection,adhesive joint.Compared with mechanical connections,glued joints have better performance in heterogeneity,sealing and fatigue resistance.It can be seen that studying the properties of adhesive joints and improving the strength of bonding joints can provide important guidance for the effective application of this technology and have a very profound significance for the effective bonding of composite materials and metal materials.In this paper,the bonding properties of GFRP-stainless steel casing joints are studied according to the factors that affect the bonding joints.The main work of the study is as follows:Firstly,the tensile test of GFRP-stainless steel casing joint was carried out,and the effects of adhesive process parameters such as length of adhesive layer and thickness of adhesive layer on tensile strength of adhesive joint were studied.The experimental results show that the tensile strength of the joint increases with the increase of the length of the adhesive layer in the range of 30 mm to 45mm;In the range of 0.25 mm to 0.6mm,the tensile strength of the bonding joint increases first and then decreases with the increase of the thickness of the adhesive layer,and the tensile strength is the largest when the thickness of the adhesive layer is about 0.4mm;The failure of adhesive joints is characterized by mixed failure and failure by adhesives,and there is a very obvious stress concentration phenomenon at the end of the joints.Then,the finite element model of GFRP-stainless steel sleeve adhesive joint was established by ANSYS software.The stress distribution and the change rule of adhesive layer during the drawing process were analyzed under different technological parameters.The simulation results show that the stress concentration area of the adhesive joint is located at the end of the adhesive layer,especially at the end of the clamping;With the increase of the length of the adhesive layer,the peak stress of the joint decreases;With the increase of the thickness of the adhesive layer,the peak stress of the joint decreases first and then increases.When the thickness of the adhesive layer is 0.4 mm,the peak stress of the joint is the smallest.The simulation results of tensile strength under different length and thickness of rubber layer are very close to the experimental results,and the error is less than 10%.Finally,the fatigue test of GFRP-stainless steel casing joint is carried out,and the influence of the length and thickness of adhesive layer on the life of adhesive joint is studied.The experimental results show that the life of the joint increases with the increase of the length of the rubber layer in the range of 30-45 mm;The life of the joint increases with the increase of the length of rubber layer,and the life of the joint increases first and then decreases when the thickness of rubber layer is in the range of 0.25-0.6 mm.When the thickness of the rubber layer reaches 0.4 mm,the life of the joint is the largest;In order to ensure the safety of the structure,there is a match between the length of glue and the thickness of glue.In the case of certain glue thickness,increasing the length of glue can increase the life,but under the condition of certain length of glue,increasing the thickness of glue may lead to the decrease of life.