Fatigue and micro-seismic behaviors of concrete disks exposed to cyclic Brazilian testing: A numerical investigation based on a 3D particle-based model

This article aims to numerically investigate the mechanical behaviour of concrete Brazilian Disk (BD) samples when exposed to multi-level cyclic Brazilian loading. A numerical 3D particle-based model was successfully established to simulate the dynamic stress-controlled cyclic testing. A generalized model is proposed based on the time-dependent evolution of bond diameter. This model shows great effectiveness in terms of reproducing the stress-strain curves, axial strain evolution and displacement fields as observed during lab testing. An acoustic emission (AE) tracking algorithm was implemented in the model to characterize and visualize the released AE energy connected with micro fracturing. The AE energy is found to be stress-level dependent which is consistent with lab testing. The failure pattern in numerical simulation is also in line with lab results. The distinctions between cyclic compressive and cyclic Brazilian tests are discussed and summarized.

Automated summary

This article investigates the mechanical behavior of concrete Brazilian Disk (BD) samples under multi-level cyclic loading through numerical analysis. A particle-based 3D model is successfully established to simulate the dynamic stress-controlled cyclic testing. A generalized model based on the time-dependent evolution of bond diameter is proposed, which effectively reproduces the observed stress-strain curves and displacement fields. An acoustic emission (AE) tracking algorithm is implemented to analyze the released AE energy associated with micro fracturing, which is found to be dependent on stress levels. The numerical simulation results and failure pattern are consistent with the experimental results. The differences between cyclic compressive and cyclic Brazilian tests are discussed and summarized.