Mesoscale Dynamic Fracture Analysis Approach of Concrete Structures Combining Finite Particle Method and Rate-Dependent Cohesive Zone Model

The fracture behavior of concrete structures under dynamic loading exhibits rate-dependent (RD) characteristics. To study the dynamic fracture (DF) mechanisms of two-dimensional (2D) concrete structures, this study proposes a DF analysis method with a novel integration of the finite particle method (FPM) and a RD cohesive zone model (CZM), which enables effective analysis of mesoscale DF in concrete. Specifically, a traction-separation law is presented, wherein only the traction strength is RD. The changes in traction with the loading rate for CZM are derived. Subsequently, the equations of motion of particles are detailed, and the internal forces of the cohesive element (CE) are developed to characterize the RD CZM. Afterward, a CE solver is implemented within the explicit FPM analysis framework. Then, a benchmark study on a single element is conducted to verify the traction-separation law of CZM. A standard DF benchmark is examined to validate the effectiveness of the proposed method. It is found that the offered approach effectively captures the path of crack propagation and the delaying characteristics of microcrack development. Applying the mesoscale fracture model of concrete structures, the intricate DF behavior of concrete is analyzed, providing enhanced understanding of crack expansion and load-bearing capacity.