Experimental And Numerical Simulation Investigation Of2A10Aluminum Alloy Rivet In Electromagnetic Riveting

There will be many large diameter rivets in large launch rocks and new aircraftsby the demanding of big load. As a new riveting method, Electromagnetic riveting(EMR) has many characteristics, such as, high loading rate, very short forming time(in milliseconds), uniform expansion of the rivet shank etc. It can effective improveriveting quality and provide solutions to the large diameter rivets’ forming. Thisdissertation focused on the2A10aluminum alloy rivet with10mm diameter,through the numerical simulation and experiments of EMR, the mechanicalproperties of the joint and the microstructure of the rivet head were studied, and therelationship between them were discussed.By using the ANSYS finite element analysis software for numerical simulationof EMR, deformation of the rivet was found successively through whole upsettingand local upsetting two stages. With the same discharge capacitance, dischargevoltage increased and same discharge energy, discharge capacitance increased, themagnetic pressure, the diameter of the rivet head, the interference of the rivet shankand the temperature in the rivet were all increased. With the increase of rivet’slength in EMR, the rivet head’s diameter changed a little, head’s height reduced, andthe rivet’s whole upsetting time and temperature increased.EMR can be used for the2A10aluminum alloy rivet with10mm diameter andthe size of the rivet head met the requirements by doing constraint modelexperiments. The best discharge parameters and the best overhang of the rivet werealso found by doing constraint model experiments. With the same dischargecapacitance, discharge voltage increased and same discharge energy, dischargecapacitance increased, the diameter of the rivet head increased. The interference ofthe rivet shank reached2~3%for the rivets whose head met the requirements. EMRis not sensitive to the thickness of the connecting sheets. The shear zone was foundin the rivet head, branches appeared when the deformation reached a high level. Thebranches started from the shear zone and extended to the surface of the rivet andformed cracks there. Along the shear zone, the hardness of the rivet decreased fromthe surface to the inside; along the vertical direction of the shear band, hardnessreached maximum at the shear zone.The damage form of the EMR sample when conducted the shear test andpulling test were found. By doing the pulling test of45degree, the rivet joint’seasiest destroy mode was shearing. Severe deformation occurred at the damagefracture. Compared the2A10aluminum alloy with10mm diameter rivet joint andthe30CrMnSi alloy with6mm diameter bolt connection, the rivet joint’s damage force was larger than the bolt connection, and the weight of the rivet was muchlighter.