Numerical Simulation of Crack Propagation in Concrete with Prefabricated Array Fractures Based on the Discrete...

Area of Science:

• Civil Engineering
• Materials Science
• Computational Mechanics

Background:

• Concrete structures are susceptible to cracking under service loads, compromising safety.
• Understanding crack propagation is crucial for structural integrity.
• Existing research often focuses on isolated fracture parameters.

Purpose of the Study:

• To investigate the coupled effects of fracture inclination, length, and quantity on concrete crack propagation.
• To establish a quantitative relationship between microcrack spatial distribution and mechanical degradation.
• To provide insights into the stability of defective concrete structures.

Main Methods:

• Utilized the discrete element method (DEM) with PFC2D 5.0 software.
• Constructed mesoscale concrete models with pre-existing internal fractures.
• Performed uniaxial compressive loading simulations and parametric analyses.

Main Results:

• Specimens with larger fracture angles had higher compressive strength but more microcracks.
• Shorter fractures improved mechanical strength and microcrack density.
• Longer fractures significantly reduced strength and limited secondary crack formation.
• Fewer internal defects improved compressive strength and fracture network coverage.
• Intact concrete exhibited superior overall performance compared to fractured specimens.

Conclusions:

• Microcrack spatial distribution, not quantity, is the key indicator of concrete damage.
• Evenly distributed microcracks maintain residual strength.
• Concentrated microcracks lead to abrupt loss of load-carrying capacity.
• Findings offer theoretical references for evaluating defective concrete structures.