An open-source C++ implementation of parallel accelerated beam-particle model for fracture analysis of brittle materials and laminated structures

This paper presents a two-dimensional beam-particle coupled numerical framework to accurately capture the mechanical responses, progressive fracture, and catastrophic failure of brittle materials and laminated engineering structures. Euler–Bernoulli beam elements represent inter-particle bonding, with a force–displacement constitutive relation and a strain-rotation coupled failure criterion to simulate bond damage and fracture. A sorting-scanning algorithm optimizes contact detection, reducing the computational cost compared with global traversal, accommodating polygonal particles with multiple vertices, and determining contact force direction and magnitude under diverse configurations with improved robustness. An implicit backward difference predictor–corrector scheme enhances numerical stability, while OpenMP-based CPU parallel computing boosts efficiency for large-scale systems. We validate the model through rock tension/compression, concrete with varying aggregate contents, and concrete three-point bending combined with compression tests on multi-contact laminated structures. Results reproduce the influence of aggregate content on concrete stiffness, strength, and fracture patterns, as well as brittle flexural fracture and progressive interfacial slip in laminated structures. Dimensional limitations of the 2D model and technical bottlenecks in 3D modeling are discussed. The improved beam-particle model demonstrates satisfactory accuracy and computational efficiency in the considered benchmark tests, providing reliable numerical support for damage mechanism analysis and stability assessment in geotechnical and structural engineering.