Applying viscoplastic constitutive models to predict ratcheting behavior of sintered nanosilver lap-shear joint

• Nanosilver joint is highly shear strain rate dependent and temperature dependent.
• Both OW–AF model and Anand model agree well with monotonic shear tests.
• Anand model overpredicts ratcheting displacements, especially at high temperature.
• OW–AF model predicts the cyclic ratcheting behavior well at different conditions.

A series of displacement-controlled tests were conducted for sintered nanosilver lap-shear joints at different loading rates and temperatures. The relationship between force and displacement was studied. It was found that higher loading rate or lower temperature caused higher stress–strain response of the sintered nanosilver joint. Force-controlled cyclic tests were also performed at different mean forces, force amplitudes, dwell time at peak force, and temperatures. The mean force, the force amplitude, and the temperature played key roles in the shear ratcheting strain accumulation. The ratcheting strain rate could be enhanced with increasing the dwell time at peak force as well. A viscoplastic constitutive model based on Ohno–Wang and Armstrong–Fedrick (OW–AF) non-linear kinematic hardening rule, and Anand model were separately embedded in ABAQUS to simulate the shear and the ratcheting behavior of the sintered nanosilver joint. It was concluded that OW–AF model could predict the ratcheting behavior of the sintered nanosilver joint better than Anand model, especially at high temperatures.