Crack Propagation Patterns Research Articles

Hybrid Reinforced Concrete Frames with Engineering Cementitious Composites: Experimental and Numerical Investigations

Reinforced concrete (RC) structures are vulnerable to damage under dynamic loads such as earthquakes, necessitating innovative solutions that enhance both performance and sustainability. This study investigates the integration of Engineered Cementitious Composites (ECC) in RC frames to improve ductility, durability, and energy dissipation while considering cost-effectiveness. To achieve this, the partial replacement of concrete with ECC at key structural locations, such as beam–column joints, was explored through experimental testing and numerical simulations. Small-scale beams with varying ECC replacements were tested for failure modes, load–deflection responses, and crack propagation patterns. Additionally, nonlinear quasi-static cyclic and modal analyses were performed on full RC frames, ECC-reinforced frames, and hybrid frames with ECC at the joints. The results demonstrate that ECC reduces the need for shear reinforcement due to its crack-bridging ability, enhances ductility by up to 25% in cyclic loading scenarios, and lowers the formation of plastic hinges, thereby contributing to improved structural resilience. These findings suggest that ECC is a viable, sustainable solution for achieving resilient infrastructure in seismic regions, with an optimal balance between performance and cost.

Hybrid CFRP‐GFRP sheets for flexural strengthening of continuous RC beams: Experimentation and analytical modeling

AbstractContinuous reinforced concrete (RC) beams cast in place are commonly used in construction; however, there is a notable gap in the literature regarding the performance of continuous RC beams strengthened with fiber‐reinforced polymer (FRP) sheets. Strengthening RC beams with FRP sheets typically leads to reduced ductility and moment redistribution capacity due to the linear stress–strain behavior of FRP materials compared to non‐strengthened RC beams. Addressing this gap, this study explores the feasibility of enhancing the mechanical properties and ductility of strengthened elements through a hybrid approach, combining carbon‐fiber‐reinforced polymer (CFRP) and glass‐fiber‐reinforced polymer (GFRP) sheets. An experimental program was conducted, retrofitting two continuous two‐span RC beams (250 × 150 × 6000 mm) with hybrid CFRP‐GFRP (HCG) sheets. Concentrated loads were applied at the center of each span, and comprehensive data on strains in FRP sheets, longitudinal reinforcements, and crack propagation patterns were recorded and meticulously analyzed. The outcomes demonstrated that employing HCG sheets for strengthening RC continuous beams significantly improves ductility, load‐carrying capacity, and moment redistribution, surpassing the performance of beams strengthened with either CFRP or GFRP sheets. To ensure accurate predictions of the flexural response, an analytical model was developed and rigorously verified using the experimental results. The model takes into account the strain compatibility condition and provides insights into the behavior of continuous RC beams strengthened with CFRP, GFRP, and HCG sheets. This research contributes valuable knowledge to the understanding of FRP sheet strengthening techniques, emphasizing the efficacy of HCG sheets for achieving enhanced structural performance in continuous RC beams.

Crack Control in Additive Manufacturing by Leveraging Process Parameters and Lattice Design.

This study investigates the design of additive manufacturing for controlled crack propagation using process parameters and lattice structures. We examine two lattice types-octet-truss (OT) and diamond (DM)-fabricated via powder bed fusion with Ti-6Al-4V. Lattice structures are designed with varying densities (10%, 30%, and 50%) and process using two different laser energies. Using additive-manufactured specimens, Charpy impact tests are conducted to evaluate the fracture behavior and impact energy levels of the specimens. Results show that the type of the lattice structures, the density of the lattice structures, and laser energy significantly influence crack propagation patterns and impact energy. OT exhibits straighter crack paths, while DM demonstrates more random fracture patterns. Higher-density lattices and increased laser energy generally improve the impact energy. DM consistently outperformed OT in the impact energy for angle specimens, while OT showed superior performance in stair specimens. Finally, a case study demonstrates the potential for combining OT and DM structures to guide crack propagation along predetermined paths, offering a novel approach to protect critical components during product failure.

Mechanical Analysis and Optimization of Concrete Structures Based on Advanced Finite Element Method

This article explores the mechanical analysis and optimization problems of concrete structures based on the Advanced Finite Element Method. By integrating advanced numerical techniques with practical engineering cases, this study aims to improve the safety and economy of concrete structure design. Firstly, the paper outlines the limitations of traditional finite element methods in concrete structure analysis, such as insufficient computational accuracy and low computational efficiency. Subsequently, by introducing AFEM, we significantly improved the accuracy and efficiency of the analysis. For example, when simulating a complex bridge structure, AFEM not only reduces the calculation time by about 25%, but also improves the accuracy of stress distribution prediction by more than 10%. In the optimization stage, we utilized the analysis results of AFEM and optimized the material consumption, cross-sectional dimensions, and reinforcement parameters of concrete structures through multi-objective optimization algorithms. A comprehensive data analysis underscores that the optimized concrete structure triumphantly meets all safety performance criteria while achieving a remarkable 12% reduction in material usage. This substantial material savings translates into a substantial 8% decrease in overall construction costs, significantly bolstering the project’s economic feasibility. Moreover, these cost savings not only amplify the project’s profitability but also play a pivotal role in enhancing the structure’s longevity and durability, thereby contributing to its sustainable performance over its entire service life. Furthermore, we delved into the capability of AFEM in simulating intricate phenomena such as the nonlinear behavior of concrete materials, crack propagation patterns, and the intricate interactions between steel reinforcements and concrete. These complex mechanical behaviors are crucial for the safety and stability of structures, and AFEM provides more comprehensive and accurate references for structural design by accurately simulating these behaviors. This article conducts in-depth research on the mechanical analysis and optimization of concrete structures based on AFEM, and demonstrates the significant advantages of AFEM in improving structural safety and economy through specific data. These research results not only provide new theoretical support and practical tools for concrete structure design, but also provide valuable references for future research and application in related fields.

Fatigue life prediction of film-cooling Hole specimens with initial damage

This study investigates a Nickel-based single crystal (SX) superalloy with femtosecond laser-drilled film-cooling holes (FCHs) under varying temperatures (room temperature, 850 °C, and 980 °C), employing a novel framework for predicting fatigue life based on initial manufacturing damage quantification. For all tested anisotropic SX superalloy specimens (including smooth and FCH specimens), the initial damage state is characterized as an equivalent initial flaw size (EIFS), and an EIFS calculation model considering stress concentration is established. Subsequently, the fatigue crack paths and microstructural characteristics of the FCH specimens at different temperatures are analyzed, elucidating crack initiation mechanisms and propagation patterns. A novel incremental plasticity J-integral driving force for fatigue crack propagation is introduced. By incorporating the closure effect of small crack propagation and employing Markov Chain Monte Carlo simulations for determining crack growth rate probabilities, a more accurate expression for the crack growth rate in relation to ΔJfat − ΔJth is derived. This expression comprehensively captures crack patterns on crystallographic planes and Type I mixed mode behavior. Finally, the total fatigue life of the FCH structures, featuring a threefold dispersion zone in both room and high-temperature environments, is predicted through experimental observations and description of crack growth rates. The predicted outcomes significantly outperform those of the conventional life prediction models reliant on crystal plasticity theory.

Comparative analysis of delamination resistance in CFRP laminates interleaved by thermoplastic nanoparticle: Evaluating toughening mechanisms in modes I and II

The study considers the delamination resistance of carbon/epoxy laminates modified with Thermoplastic Nanoparticles of Polysulfone (TNPs). A new electrospinning nanofiber technique was utilized to convert polysulfone polymer into nanoparticles and uniformly disperse them within the resin. Fracture toughness was evaluated under loading modes I and II. In mode I, the toughness (GIC) increased significantly from 170 to 328 J/m² with TNPs incorporation. However, mode II showed minimal change, with GIIC values of 955 J/m² for virgin and 950 J/m² for TNPs-modified specimens. Scanning Electron Microscopy (SEM) was employed to depict the influence of TNPs on damage characteristics and crack propagation patterns. In mode I, crack deviation enhanced toughness as TNPs bypassed the PSU, while in mode II, cracks propagated through TNPs, resulting in particle smearing on the epoxy surface. This highlights TNPs' potential to modify the fracture toughness in mode I loading, but their effect is constrained in mode II loading scenarios.

Mechanical properties and damage constitutive relationship of microwave irradiation of granite under uniaxial compression

Microwaves have great potential to increase the efficiency of hard rock breakage during mechanical excavation in engineering. This study conducted uniaxial compression tests on granite specimens after microwave irradiation at 4.85 kW. The results demonstrated a linear decrease in uniaxial compressive strength and elastic modulus correlating with increasing irradiation durations. Acoustic emission data indicated increased normalized crack closure stress and decreased normalized crack initiation and damage stress, suggesting complex crack propagation and evolution patterns under microwave influence. 3D Digital Image Correlation revealed that as heating time increased, the macrocrack leading to specimen failure shifted from being load-dominated to involving both load and microwave-induced thermal cracks. A simple four-parameter damage constitutive model for granite (a 1, r 1 , a 2, and r 2) effectively described the damage evolution under the coupling effect of microwave and uniaxial load. The model accurately characterized the complete stress–strain curves, including both microcrack compaction and post-peak stages, revealing that initial damage escalates with longer heating, though the progression rate decreases.

Enhancing flexible electronics: Unveiling the role of strain rate in the performance of molybdenum-coated PET films

This work analyzes the mechanical and electrical properties of molybdenum (Mo) thin films at 100 and 200 nm thicknesses under different strain and strain rate circumstances. The study examines Mo film deposition by RF magnetron sputtering on PET substrates and their mechanical stress behavior. The investigation reveals distinct patterns of crack initiation and propagation, where primary cracks predominantly appear perpendicular to the direction of applied strain, and secondary cracks develop due to stress redistribution, displaying a complex interplay between film thickness, strain rate, and crack morphology. A key finding of this study is the observation of more advanced and irregular crack patterns in thicker films (200 nm) subjected to higher strain rates (1000 mm/min), suggesting a heightened sensitivity to mechanical stress and a more chaotic fracture process compared to thinner films or those under lower strain rates. Additionally, instances of film edge delamination, particularly under high strain conditions, highlight the challenges in maintaining film-substrate adhesion and integrity under extreme mechanical deformation. The research provides critical insights into the mechanical robustness and electrical performance of Mo thin films, emphasizing the influence of microstructural properties, deposition parameters, and external stressors on their applicability in high-tech industries. The findings underscore the importance of optimizing deposition techniques and understanding material behavior under stress to enhance the durability and reliability of Mo thin films in practical applications, ranging from semiconductor devices to photovoltaic systems.

Effect of shear span-to-depth ratio on flexural and fracture behaviors of reinforced UHPMC beams based on four-point bending test and acoustic emission monitoring

Ultra-high performance manufactured sand concrete (UHPMC), using manufactured sand (MS) as aggregate, belongs to a brand-new ultra-high performance concrete (UHPC). Better understanding the failure behavior of UHPMC beams reinforced with steel reinforcement bars is crucial in structural design. This study investigates the effects of different shear span-to-depth ratios (λ = 1.2, 1.6 and 2.0) on the failure modes, mid-span deflection, concrete and rebar strain, flexural toughness, initial cracking load, ultimate load, energy dissipation capacity, and crack propagation patterns based on four-point bending tests for totally twelve reinforced UHPMC beams. Meanwhile, acoustic emission (AE) monitoring is used to evaluate corresponding fracture characteristics. Results reveal that an increase in shear span-to-depth ratio leads to a significant increase in mid-span strain and better ductility but lower equivalent stiffness. The maximum strain of specimen with λ = 1.2 is 24.8 % lower than that with λ = 2.0, and specimen with λ = 1.6 exhibits 22.3 % greater equivalent stiffness than that with λ = 2.0. Beams with larger shear span-to-depth ratios demonstrate superior ductility and energy absorption capacity, specimen with λ = 2.0 showing a ductility factor 2.85 times higher than that with λ = 1.2. The presence of MS significantly improves initial cracking load by 26.9 %, ultimate load by 4.5 %, and energy dissipation capacity by 37 %. MS also enhances toughness and delays crack propagation in the early stages. This effect can make the fracture transform into more rapid energy release in the later stages, indicating that MS could alter crack propagation patterns, forcing cracks to propagate along paths with greater resistance to crack propagation. These conclusions can offer insights for the safer and economical design and application of UHPMC beams, especially the balance among shear span-to-depth ratio, MS and mechanical performance in the environmentally friendly structures design and failure prevention process.

Direct ink writing of non-sintered ceramic with biomimetic cellular structure

Cellular ceramics are highly valued for their exceptional mechanical properties and low density, making them suitable for applications like thermal insulation, impact absorption, and biomedical implants. However, high-temperature sintering required for densification can cause issues like shrinkage, loss of precision, and degradation of functional additives. This work reports a novel approach for fabricating 3D printed cellular ceramics under ambient conditions using CO2-cured γ-C2S ink via direct ink writing. The printed green body is converted into a dense matrix of CaCO3 and silica gel upon exposure to a CO2-rich environment without high temperature sintering. The non-sintered cellular ceramics achieve high compressive and specific strength comparable to sintered counterparts, with the square-shaped structure exhibiting the best performance of 104 and 171 MPa in terms of in-plane and out-of-plane compressive strength, respectively. Further, the in-situ analysis reveals distinct deformation modes and crack propagation patterns across structures, providing insights into structure-property relationships to guide the design of high-strength non-sintered cellular ceramics.

The influence of interlayer bonding conditions on the propagation laws of reflective cracks in semi-rigid base pavement based on the DEM and GPR

Reflection cracks represent the predominant internal distress in semi-rigid base asphalt pavements and often accompanied by additional secondary issues that detrimentally affect the pavement structural bearing capacity. The propagation and deterioration of reflective cracks are affected by many factors, for example the interlayer bonding conditions. It is crucial to identify the propagation and deterioration of reflective cracks to prolong the life of pavement structure. The purpose of this article is to explore the influence of interlayer bonding conditions on the propagation laws of reflective cracks. This work employs the discrete element method(DEM) to explore the propagation patterns of reflection cracks accompanied different bonding conditions between the surface layer and base layer subjected to moving load. The results of discrete element simulation reveal a three-phase progression laws when the reflective cracks expand from the base layer to the pavement surface，involving rapid propagation, stable propagation, and failure process. With the interlayer bond strength decreases, expansion of reflective crack is significantly accelerated. Meanwhile, once the critical bond strength threshold is reached, complete debonding will occur between the surface and base layers. The results are ultimately verified through the core sampling from practical engineering using three-dimensional (3D) ground penetrating radar(GPR) detection, along with the radar image recognition of reflective cracks and poor interlayer bonding. The results will serve as a foundation for researching the mechanism and treatment measures for two internal pavement distress, namely reflection cracks and poor interlayer bonding.

Multi-scale investigation of silane coupling agent for enhanced corrosion resistance in reinforced concrete

Reinforcement corrosion is a significant factor leading to the deterioration of building performance. In order to enhance the serviceability of reinforced concrete under corrosive environments, this study employs a silane coupling agent (γ-aminopropyltriethoxysilane) for steel reinforcement treatment. The anti-corrosion mechanism, crack propagation patterns, and modified corrosion resistance of the steel are investigated at multiple scales. Experimental techniques such as scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR) are utilized to explore the influence of the self-assembled coating of the silane coupling agent on the microscopic morphology, elements, and functional groups of the steel. Concrete specimens with treated reinforcement are fabricated, and electrochemical accelerated corrosion tests are conducted to compare corrosion differences among different specimens. Using untreated specimens as a control group, digital image correlation (DIC) technology is employed to capture the full-field strain and displacement distribution during the loading process. The crack propagation and slip behavior at the steel-concrete interface in the composite specimens are analyzed. The research findings indicate that, at the optimal concentration of 1.2 %, the self-assembled coating of the silane coupling agent successfully adheres to the steel surface, significantly enhancing the interfacial abrasion resistance and mechanical strength of the steel-concrete interface, thereby validating the improved corrosion resistance of the steel. This study proposes the self-assembly mechanism and interfacial enhancement mechanism of the silane coupling agent on steel at multiple scales, contributing to a comprehensive understanding of its effectiveness.

Effect of hot isostatic pressing on stress-rupture crack growth of a single-crystal nickel-based superalloy

The solution-treated second-generation single crystal (SX) superalloys underwent hot isostatic pressing (HIP) at 1316 °C and 105 MPa for varying durations. This study investigates the effect of HIP on micropores and stress-rupture behavior under conditions of 980 °C and 250 MPa. The results illustrate that the application of HIP treatment significantly reduces the porosity and volume of micropores, thereby increasing the rupture life of the alloys. With the disappearance of micropores, the crack initiation site shifts from the micropores to the γ/γʹ interface, resulting in reduced crack dimensions and decelerated propagation. Consequently, the smaller size of cracks in HIPed specimens slow down fracture. Nonetheless, the crack propagation pattern remains consistent: cracks expand perpendicular to the stress axis, connecting with cracks at other heights via secondary cracks along the <112> direction.

Impact fracturing of rock-like material using carbon dioxide under different temperatures and pressures

Unconventional resources (oil, gas, and geothermal) are often buried deep underground within dense rock strata and complex geological structures, making it increasingly difficult to create volumetric fractures through conventional hydraulic fracturing. This paper introduces a novel method of supercritical energetic fluid thermal shock fracturing. It pioneers a CO2 deflagration impact triaxial pneumatic fracturing experimental system, using high-strength similar materials to simulate deep, hard rock masses. The study investigates the rock-breaking process and crack propagation patterns under supercritical CO2 thermal shock, revealing and discussing the types of thermal shock-induced fractures, their formation conditions, and discrimination criteria. The research indicates that higher supercritical CO2 thermal shock pressures and faster pressure release rates facilitate the formation of radial branching fractures, circumferential cracks, and branch cracks. Typically, CO2 thermal shock generates 3–5 radial main cracks, which is significantly more than the single main crack formed by hydraulic fracturing. The formation of branched cracks is often caused by compression-shear failure and occurs under relatively harsh conditions, determined by the confining pressure, rock properties, peak thermal shock pressure, and the pressure sustained post-decompression. The findings are expected to offer a safe, efficient, and controllable shockwave method of supercritical fluid thermal shock fracturing for the exploitation of deep unconventional oil and gas resources.

Crack Behavior of Eccentrically Braced Frame Type-V with Ground Granulated Blast Furnace Slag

To make the structure stronger and stiffer, which is more susceptible to earthquake forces, a special mechanism is required to improve the structure's lateral stability. EBF-V with a horizontal link beam is a brace that can enhance structural performance by providing good stiffness and ductility. On the other hand, GGBFS, as a partial OPC replacement material, was applied to contribute to using more environmentally friendly materials. Besides offering a smaller carbon footprint, GGBFS also positively improves the mechanical properties of concrete. Thus, this study focuses on investigating the crack propagation pattern of reinforced concrete braced frames combined with 20% GGBFS in EBF-V with three variations of link beam element lengths of 0 cm (CBF), 15 cm (EBF-V-) and 25 cm (EBF-V-25). As a result, the CBF specimen showed the best seismic performance. In EBF specimens, there is an increase in the collapse mechanism to be more ductile. The link beam plays a role in making the crack pattern more focused. EBF-V-15 performs well under seismic loading with large lateral capacity and ductility. The cracks in the frame are evenly distributed, dominated by fine cracks, and symmetrical on both sides. This validates that GGBFS plays a good role in improving the frame performance with its pore-filling effect and pozzolanic reaction.

Experimental investigation of bending fatigue behaviors for T-shaped welded joint

A fatigue test was conducted on a T-shaped welded joint under three-point bending conditions. Prior to the test, the geometry of the weld toe on both sides of the specimen was observed and measured. The locations of Fiber Bragg Gratings (FBG) strain gauges were determined based on the weld toe’s geometric features. During the experiment, a 2-level load spectrum block of cyclic loading was applied, resulting in distinct beach marks on the fatigue fracture surface. The stress-time history of the weld toe’s geometric features was monitored. After the test, the fatigue fracture was observed and measured, the influence of the crack path on the crack propagation rate was analyzed, and the influence of the crack propagation pattern on the stress evolution in the nearby area was studied. The experimental results show that the multiple cracks initiation positions have strong relationship with the characteristic points of weld toe morphology. Based on the Linear Elastic Fracture Mechanics (LEFM) theory and the concept of varying remote stress, four crack propagation simulation patterns were constructed and carried out. The results show that the varying remote stress has an more important influence on life prediction of welded joints, while the threshold mainly affect the life prediction of the early stage.

Optimization of geopolymer pervious concrete design using multi-phase discrete element modeling

This study aims to optimize mix designs of geopolymer pervious concrete using multi-phase discrete element modeling. Metakaolin based geopolymer concrete was prepared with different mix designs for laboratory testing. A multi-phase discrete element model (DEM) for pervious concrete was developed with randomly generated porous structure and realistic contact models between each component. Contact model parameters were calibrated using orthogonal analysis based on measurements of mechanical strengths and elastic modulus. Results of model validation indicate that the developed numerical model has good reliability to predict mechanical properties of pervious concrete with the influence of porosity. Both actual and simulated pervious concrete specimens present consistent crack propagation patterns and failure behavior. The optimization of mixture design is conducted by considering aggregate gradation and aggregate to paste ratio of geopolymer pervious concrete, which are based on experimental results and post-calibration simulations. The gradation with larger size aggregate is suitable for preparing geopolymer pervious concrete with higher permeability and tensile strength. More importantly, it is feasible to reduce paste content in geopolymer pervious concrete while maintaining similar or even higher mechanical strengths, which reduces the embedded carbon footprint. The study findings demonstrate the beneficial use of numerical modeling to determine the optimized mix design of composite material such as geopolymer pervious concrete.

Consideration of the effects of frost heave force and train loads on the cracks and propagation pattern of ballastless track slabs in cold regions

The construction of ballastless railway tracks in cold regions is susceptible to frost heave forces, which may particularly impact the stability of track slab cracks and lead to crack propagation. In this paper, the frost heave tests are conducted on the concrete specimens with prefabricated cracks to observe the evolution of the frost heave force within the cracks. The frost heave force is subsequently applied to the finite element model of the concrete specimens to calculate the stress intensity factors (SIFs). In addition, the CRTS III ballastless track model is established to investigate the crack propagation patterns under frost heave and train loads. The results show that the frost heave force in concrete cracks during freezing and thawing is divided into five stages, which produces two peaks of frost heave force. Train loading caused the SIFs of the crack tips to open and close alternately and to rise significantly under the coupling effect of frost heave load. The SIF increases approximately linearly with crack width and is higher for transverse cracks than for longitudinal cracks. Small size cracks do not possess sufficient SIF values to exceed fracture toughness, implying no crack propagation. However, as the crack width is constantly increasing, the SIF will eventually exceed the fracture toughness. Therefore, strict control over track slab's crack width is necessary for CRTS III ballastless tracks.

Experimental investigation on macroscopic fracture and microstructural evolution of granite under high-temperature steam action

This study conducted simulated experiments on the thermal fracturing of granite under non-uniform stress conditions using the method of injecting high-temperature and high-pressure steam. Additionally, a comprehensive investigation was carried out on the thermal fracturing characteristics of granite after steam treatment, as well as the distribution patterns of cracks. The results show that: Firstly, the process of fracturing granite using high-temperature and high-pressure steam as a medium can be divided into five stages. The threshold temperature for thermal fracturing of granite is 260 ℃, at which point a large number of cracks develop or form interconnected networks. Secondly, under high-temperature conditions, the tensile strength of granite is greatly reduced. The temperature at which brittle fracture occurs in granite during the experiment was found to be 427 ℃ at a steam pressure of 10.6 MPa. Thirdly, under the influence of high-temperature and high-pressure steam, granite not only generates primary cracks along the direction perpendicular to the minimum principal stress but also produces a certain number of secondary cracks in other directions. The crack propagation direction can be determined from the velocity and permeability distribution maps of fractured granite. Finally, the fracture surface of granite exhibits significant brittle characteristics. The fracture morphology mainly includes transgranular and intergranular fractures. In the experiment, the fracture surface also showed fragmented and fatigue-induced fracture features. The fractal dimension of micro-morphological features can be used to assess the extent of thermal fracturing at different locations on the fracture surface. Through macroscopic fracturing experiments and comprehensive analysis of theory, wave velocity, and micro-morphology, the study obtained relevant crack propagation patterns and the formation of cracks in different directions. This is of practical significance in the formation of interconnected spatial fracture networks, thereby helping to increase the thermal exchange surface area of artificial reservoirs and improve the efficiency of geothermal exploitation.

Numerical simulations on the structural heterogeneity and fracture bias effect of three-point bending specimen

Granite is a common surrounding rock in tunnels, nuclear waste repositories, and other underground engineering. It is essential to investigate granite’s mechanical behavior and fracture mechanism at the mesoscale. In this paper, the three-point bending model considering granite meso-heterogeneity was constructed, and the three-point bending test and acoustic emission (AE) simulation were carried out under different crack sizes and porosities, different prefabricated fracture offset distances, and bedding conditions. The results show that large-size mineral particles and intrinsic fractures mainly determine the sample’s crack propagation pattern. As the prefabricated crack’s deviation distance increases, the sample’s peak load, fracture energy, number of AE events, and internal damage range all gradually rise. The sample’s crack propagation path has a distinct step shape due to bedding, and tensile fractures primarily occur in the through-layer crack, whereas shear fractures mainly occur at the bedding plane. The specimen’s surface crack’s fractal dimension is positively associated with the cumulative acoustic emission energy during the fracture process. The conclusion of the research can offer a theoretical foundation for analyzing the stability of the surrounding rock.