Study On Forming Simulation Of Clinch-adhesive Joints Of Steel And Aluminum Dissimilar Materials

Aluminum alloys are increasingly used in automotive bodies.For steel and aluminum dissimilar materials connection,the main connection technologies used at this stage include:Clinching,Self-piercing Riveting and Bonding.The introduction of Bonding into Clinching improves the mechanical properties of the joints and also prevents electrochemical corrosion.In the research field of adhesive and clinched joints,scholars mainly focus on the mechanical properties of the joints,and there are fewer studies on the morphology of joints.The appearance of the joints not only affects the forming quality of the joint and thus affects the mechanical properties,but also relates to the electrochemical corrosion of the joint.In this paper,the production process of clinching after curing is used to study the forming process and forming morphology of the joints.It mainly includes:Select the appropriate steel plate,aluminum alloy plate and adhesive,and use the universal tensile machine and VIC-3D non-contact strain gauge measurement method to obtain the mechanical properties of the material.A uniaxial tensile finite element model was established to simulate the uniaxial tensile tests of three materials,and the correctness of the obtained mechanical properties parameters was verified.The design of clinching joints and clinch-adhesive joints was designed,and the production method of clinch-adhesive joints was introduced in detail.The two types of joints obtained in the experiment were cut out of the section.Using the values of neck thickness and self-locking as standards,the shape of the two joints was compared and the conclusion was drawn: the value of the neck thickness of the clinch-adhesive joints is slightly smaller than that of the clinching joints,and the self-locking value is reduced by approximately 1/3.The conductivity of the caulking joint was tested and found to be insulative.This proves that the adhesive remains in the joint and isolates the steel and aluminum plate.A finite element model was established to simulate the forming of the clinching joints and the clinch-adhesive joints.The simulation results were in accordance with the experimental results.The forming mechanism of the clinch-adhesive joints was studied with the aid of the forming process.The finite element simulation model was used to explore the effects of adhesive layer thickness,punch stroke,die depth,die diameter and punch fillet radius on the forming morphology of clinch-adhesive joints.And analyzed the distribution of the adhesive layer.