Stress Concentration Area Research Articles

Comparative analysis of armid fiber reinforced polymer for strengthening reinforced concrete beam‐column joints under cyclic loading

AbstractThis research investigates the structural performance and failure mechanisms of beam‐column joints reinforced with aramid fiber‐reinforced polymer to bolster the durability and seismic resilience of concrete structures. It meticulously selects and proportions materials such as ordinary Portland cement Grade 53 cement, fine and coarse aggregates meeting IS: 383–1970 standards, and water conforming to IS: 456–2000 specifications. Tests confirm the high quality of ordinary Portland cement, crucial for optimal beam‐column joint performance, while carbon fiber‐reinforced polymer enhances structural integrity with its lightweight composition and substantial tensile strength (3800 MPa–4200 MPa). Failure analysis reveals that non‐aramid fiber reinforced polymer wrapped beam‐column joint specimens predominantly failed due to concrete crushing, whereas aramid fiber‐reinforced polymer‐wrapped specimens failed due to fracture in the aramid fiber‐reinforced polymer composite, emphasizing stress concentration areas. This study underscores the pivotal role of stress distribution in failure mechanisms and underscores the significance of robust reinforcement design in bolstering structural resilience. These insights advance retrofitting strategies and reinforce techniques aimed at enhancing the longevity and seismic resistance of concrete structures.

Research on influence of stress concentration on metal magnetic memory signal for stress evaluation

Abstract Based on the magneto-mechanical effect and stress concentration effect, this paper takes the failure of ferromagnetic components caused by stress concentration as the research background, artificially creates stress concentration by prefabricating U-shaped defects, and discusses the Hp(y) signal distribution law of prefabricated U-shaped defect samples and the difference in Hp(y) signal between specimens with different tip SCFs. Results show that the Hp(y) signal has an apparent mutation in the stress concentration area, and when the stress concentration factor was the same, the magnetic field intensity gradient K becomes higher as tensile load increasing. As stress concentration factor increasing, the K value of the stress concentration area also increases gradually. Based on theoretical model of Hp(y) signal, it can be known that the K value can be used to judge the sample stress concentration degree with the results in this study.

Computed Tomography-Driven Analysis of Particle Breakage Using a Coupled FDM-DEM Approach

This study proposes a refined approach for simulating the mechanical behavior of soils under high stress by integrating the Finite Difference Method-Discrete Element Method (FDM-DEM) with in-situ experiment. This novel framework incorporates advanced technologies such as flexible membrane and X-ray computed tomography (CT) to enhance the predictive capabilities of the simulation with physical insight. The FDM-DEM model adeptly simulates irregular particle shapes, capturing their interactions and the dynamics of particle breakage. The use of flexible membrane within the model further enriches this approach by enabling the capture of deformation responses in granular materials during shearing. Moreover, the adoption of CT technology facilitates continuous optimization of the simulation process. Validation through in-situ experiments has confirmed the model's effectiveness. The ability of the model to predict areas of high stress concentration—and their correlation with observed particle breakage patterns—underscores the utility of the enhanced FDM-DEM framework as a robust predictive tool for understanding the behavior of granular materials under shearing.

Research on Pipeline Stress Detection Method Based on Double Magnetic Coupling Technology.

Oil and gas pipelines are subject to soil corrosion and medium pressure factors, resulting in stress concentration and pipe rupture and explosion. Non-destructive testing technology can identify the stress concentration and defect corrosion area of the pipeline to ensure the safety of pipeline transportation. In view of the problem that the traditional pipeline inspection cannot identify the stress signal at the defect, this paper proposes a detection method using strong and weak magnetic coupling technology. Based on the traditional J-A (Jiles-Atherton) model, the pinning coefficient is optimized and the stress demagnetization factor is added to establish the defect of the ferromagnetic material. The force-magnetic relationship optimization model is used to calculate the best detection magnetic field strength. The force-magnetic coupling simulation of Q235 steel material is carried out by ANSYS 2019 R1 software based on the improved J-A force-magnetic model. The results show that the effect of the stress on the pipe on the magnetic induction increases first and then decreases with the increase in the excitation magnetic field strength, and the magnetic signal has the maximum proportion of the stress signal during the excitation process; the magnetic induction at the pipe defect increases linearly with the increase in the stress trend. Through the strong and weak magnetic scanning detection of cracked pipeline materials, the correctness of the theoretical analysis and the validity of the engineering application of the strong and weak magnetic detection method are verified.

The effects of environments and adhesive layer thickness on the failure modes of composite material bonded joints

In this study, a structural adhesive was used to bond unidirectional prepreg and fiber fabric in a single lap joint. The mechanical properties of the structural adhesive were investigated under room temperature dry state (RTD) and elevated temperature wet state (ETW, 71 ℃/85% RH), and different adhesive layer thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm). The fracture surfaces of the bonded joints were examined using scanning electron microscopy (SEM), and finite element simulations were conducted to observe the failure modes and failure paths. Additionally, the specimens were immersed in water and hydraulic oil, and their tensile shear strength was tested to evaluate their liquid sensitivity. The experimental results indicated that with increasing adhesive layer thickness, the strength of the specimens decreased by 21% in the RTD and by 52% in the ETW. The strength differences between different environments were minimal for adhesive layer thicknesses of 1 mm and 1.5 mm. The shear strength of the specimens decreased after immersion in water and hydraulic oil, with reductions of 43.78% and 39.21%, compared to the room temperature dry respectively. SEM observations of the bonded joint sections revealed that the primary failure modes were adherend failure and adhesive layer failure. Finite element simulations indicated that fiber tearing and crack initiation occurred in stress concentration areas during loading, leading to structural failure.

Vibration fatigue behavior and failure mechanism of Ni-based single-crystal film cooling hole structure under high temperature

Film cooling hole structures significantly influence vibration fatigue performance of Ni-based single crystal turbine blades. This study investigates the vibration fatigue behavior and failure mechanism of film cooling hole structure of Ni-based single crystal superalloy at high temperature by using the plate specimens with film cooling holes. The vibration fatigue cracks are all initiated at the edge of the film cooling hole on specimen surface, and the macroscopic crack path is a straight line path. At the microscopic scale, the crack path at 850 °C is a Zigzag path, but the crack path at 980 °C still shows a straight line path. The crack initiation of the specimen shows the oxidation crack nucleation in the stress concentration area under the coupling effect of high temperature and alternating stress. The macroscopic crack propagation direction at high temperature depends on the stress gradient direction of the resolved shear stress. At the microscopic scale, the crack propagation at 850 °C is the dislocation slip-climb mechanism, and the crack propagation at 980 °C more inclined to produce only the dislocation climb mechanism. The vibration fatigue cracks have the temperature dependence. The high temperature environment promotes the activation of slip system and the enhancement of dislocation mobility, the microscopic raft structure promotes the crack propagation along the γ phase with a large number of dislocations, the oxidation crack promotes the oxygen to enter the alloy matrix, which accelerates the Mode-I crack propagation.

Oxidation behavior and failure mechanisms of enamel coatings at different temperature

This work studies the prolonged high-temperature oxidation behavior and failure mechanisms of enamel coatings at three distinct temperatures: 600°C, 800°C, and 1000°C. The evolution of the coating’s microstructural morphology was characterized, and the kinematics of porosity, crystal precipitation, and oxide layer thickness were measured. The results indicated that at 600°C and 800°C, the coatings exhibit strong oxidation resistance and retain their mechanical integrity. However, at 1000°C, the coatings rapidly deteriorate due to formation of Cr microcrystalline bands and the diffusion of oxidation layer, leading to volume expansion and element segregation. These factors result in the formation of voids and stress concentrations. The precipitation of crystals further exacerbates localized stress and microcracks, increasing the brittleness and enlarging the stress concentration areas, ultimately causing coating spallation. The effects of cooling rate on the long-term oxidation lifetime of the coatings were also examined. The findings of this work suggest that the temperatures below 800°C are suitable for long-term application of the enamel coatings, while exposure to 1000°C results in their rapid failure.

Failure analysis-based mass reduction of an aluminium alloy engine mounting bracket using Design of Experiments approach

In this study, mass reduction of an engine mounting bracket has been performed without changing the failure mode. Firstly, failure modes were determined experimentally using failure loads provided by the vehicle manufacturer. Then critical stress concentration areas and suitable mass reduction regions were determined by using Finite Element Analysis (FEA) for these load cases. A structural optimisation process was carried out using Design of Experiment-Response Surface Methodology (DOE-RSM) to minimise the mass while keeping the failure load as constant as possible. When the stress values obtained from the preliminary structure are compared with the values obtained from the optimised part, it was seen that this target has been mostly achieved. A total mass reduction of 4.31 % was achieved in the new part through failure mode analysis. Furthermore, it was found that a financial saving of 129,000 Euro could also be achieved.

Stress transfer paths and damage modes of layered coal-rock mass under static loading

In order to explore the distribution characteristics of nonlinear mechanical behavior and the tendency of damage and failure of deep in situ coal-rock mass, a layered composite thin plate coal-rock mass model is established based on thin plate theory and finite element method. The continuity of interlayer stress and displacement is maintained by transfer matrix function, and the maximum shear stress is calculated by Mohr-Coulomb strength criterion. The distribution characteristics of stress, displacement, energy and maximum shear stress of coal-rock mass under static load are obtained. The analysis results are as follows : ① The torsional stress concentration areas of τxz and τyz are formed on the boundary of coal-rock interface, and the principal stress concentration areas of σx, σy and σz are formed in the center and center of the boundary, and the shear stress distribution of τxy is formed on the diagonal line. ② The maximum shear stress of the long axis has a strengthening effect on the shear failure, and each layer forms a stress state of alternating tension-shear-compression-shear. It first destroys in the middle of the coal-rock interface and boundary, and then destroys along the long side and short side. ③ The coal-rock mass presents a ′ X ′ -type shear zone along the radial and axial. The shear failure occurs first, followed by the principal stress compression failure. The cracks are preferentially developed in the direction perpendicular to the minimum principal stress, and the stepped ′ V ′ -shaped failure characteristics are formed under the action of shear and tensile stress.

Factors Controlling Differences in Morphology and Fractal Characteristics of Organic Pores of Longmaxi Shale in Southern Sichuan Basin, China

Shale gas is a prospective cleaner energy resource and the exploration and development of shale gas has made breakthroughs in many countries. Structure deformation is one of the main controlling factors of shale gas accumulation and enrichment in complex tectonic areas in southern China. In order to estimate the shale gas capacity of structurally deformed shale reservoirs, it is necessary to understand the systematic evolution of organic pores in the process of structural deformation. In particular, as the main storage space of high-over-mature marine shale reservoirs, the organic matter pore system directly affects the occurrence and migration of shale gas; however, there is a lack of systematic research on the fractal characteristics and deformation mechanism of organic pores under the background of different tectonic stresses. Therefore, to clarify the above issues, modular automated processing system (MAPS) scanning, low-pressure gas adsorption, quantitative evaluation of minerals by scanning (QEMSCAN), and focused ion beam scanning electron microscopy (FIB-SEM) were performed and interpreted with fractal and morphology analyses to investigate the deformation mechanisms and structure of organic pores from different tectonic units in Silurian Longmaxi shale. Results showed that in stress concentration areas such as around veins or high-angle fractures, the organic pore length-width ratio and the fractal dimension are higher, indicating that the pore is more obviously modified by stress. Under different tectonic backgrounds, the shale reservoir in Weiyuan suffered severe denudation and stronger tectonic compression during burial, which means that the organic pores are dominated by long strip pores and slit-shaped pores with high fractal dimension, while the pressure coefficient in Luzhou is high and the structural compression is weak, resulting in suborbicular pores and ink bottle pores with low fractal dimension. The porosity and permeability of different forms of organic pores are also obviously different; the connectivity of honeycomb pores with the smallest fractal dimension is the worst, that of suborbicular organic pores is medium, and that of long strip organic pores with the highest fractal dimension is the best. This study provides more mechanism discussion and case analysis for the microscopic heterogeneity of organic pores in shale reservoirs and also provides a new analysis perspective for the mechanism of shale gas productivity differences in different stress–strain environments.

Open-source hand prosthesis: evaluation of mechanical feasibility and additive manufacturing potential

This study delves into the risks associated with 3D-printed hand prostheses lacking mechanical feasibility studies. Such unvalidated prostheses may exhibit various issues like durability shortcomings, anatomical incompatibility, functional safety concerns, manufacturing quality deficiencies, and health risks due to inappropriate materials. These issues can lead to damage or premature failure during use, discomfort, skin irritation, injuries, inability to withstand functional loads, and health hazards from toxic or allergenic substances. Therefore, ensuring the safety, quality, and effectiveness of these prostheses is crucial. The study focuses on a mechanical feasibility study conducted through Finite Element Analysis (FEA) simulations on an open-source hand prosthesis model. It evaluates mechanical properties, stress concentration areas, and displacement on the prosthesis surface. The methodology comprises three key steps: acquiring the virtual model, conducting computational simulations, and selecting the 3D printing material. The simulations assess the prosthesis’s ability to withstand compressive forces and identify stress concentration areas. Results from the study indicate that using PETG as the constituent material demonstrates mechanical viability and satisfactory performance under static force conditions. This finding underscores the importance of rigorous testing and adherence to standards in developing 3D-printed hand prostheses. Such studies contribute significantly to enhancing these devices’ safety and effectiveness, facilitating their broader adoption in healthcare settings. In summary, this study highlights the critical need for mechanical feasibility studies in the development of 3D-printed hand prostheses. It emphasizes the significance of following strict standards and regulations to ensure these devices’ safety, quality, and functionality. By doing so, it paves the way for the widespread use of these prostheses in healthcare, benefiting users and advancing the field of prosthetic technology.

Variation of MEMS Thin Film Device Parameters under the Influence of Thermal Stresses.

With the advancement of semiconductor manufacturing technology, thin film structures were widely used in MEMS devices. These films played critical roles in providing support, reinforcement, and insulation in MEMS devices. However, due to their microscopic dimensions, the sensitivity of their parameters and performance to thermal stress increased significantly. In this study, a Pirani gauge sample with a multilayer thin film structure was designed and fabricated. Based on this sample, finite element modeling analysis and thermal stress experiments were conducted. The finite element modeling analysis employed a combination of steady-state and transient methods to simulate the deformation and stress distribution of the device at room temperature (25 °C), low temperature (-55 °C), and high temperature (125 °C). The thermal stress test involved placing the sample in a temperature cycling chamber for temperature cycling tests. After the tests, the resonant frequency and surface deformation of the device were measured to quantitatively evaluate the impact of thermal stress on the deformation and resonant frequency parameters of the device. After the experiments, it was found that the clamped-end beams made of Pt were a stress concentration area. Additionally, the repetitive thermal load caused the cantilever beam to move cyclically in the Z direction. This movement altered the deformation of the film and the resonant frequency. The suspended film exhibited concavity, and the overall trend of the resonant frequency was downward. Over time, this could even lead to the fracture of the clamped-end beams. The variation of mechanical parameters derived from finite element simulations and experiments provided an important reference value for device design improvement and played a crucial role in enhancing the reliability of thin film devices.

Failure analysis of kingpin hole on front axle of mining truck based on finite element analysis

The axle is a critical load-bearing component of a vehicle, and its failure can lead to serious accidents. During a vertical fatigue test, the front axle of a mining truck failed prematurely. To identify the cause of this failure and enhance the structural design to meet technical requirements, a stress analysis was conducted using the finite element method. The analysis revealed areas of stress concentration on the front axle. The mechanical properties of the material were determined through tensile testing. A fatigue life analysis method, based on finite element analysis, was employed to assess the axle’s fatigue life. This method identified the location where fatigue cracks initiated and determined the minimum load cycles before the onset of fatigue cracking. The results were then compared with actual observations. Following improvements to the design based on the simulation results, another round of fatigue analysis was performed. The findings indicated a significant increase in the axle’s fatigue life, thereby meeting the required technical standards.

Fatigue Overview of Ship Structures under Induced Wave Loads

Fatigue damage represents a key failure mode in ship structures. Such damage typically begins at vulnerable points in the structure, like welded joints, stress concentration areas, and cracks. Cyclic loading, particularly from waves, encountered by ships during their operational life is a major cause of fatigue damage, which is the main focus of this study. There are various methods to address different sea state conditions, though they can sometimes be approximate. This paper aims to review the most commonly used methods to highlight their strengths and weaknesses and to provide essential background knowledge for developing reliable theoretical and numerical models for predicting the fatigue life of ship structures exposed to various sea states over their lifetime. The primary theoretical approaches discussed include energy spectral methods in both time and frequency domains, which are used to quantify wave-related energy and amplitude characteristics and evaluate wave loads for predicting the fatigue life of structures and welded joints. The discussion also covers the determination of cyclic stress in specific structural details of the hull girder and welded joints to identify the relevant maximum stress range for subsequent fatigue studies conducted using finite element analysis.

Characteristic analysis of tunnel collapse arch in weak rock mass

The stress of surrounding rock and supporting structure is very complicated during the construction of a loose rock tunnel. The characteristics analysis of collapse arch is very important for the construction safety. This paper compares and analyzes the applicability of the full section method and the three-step method under shallow buried loose surrounding rock, reveals the influence law of tunnel excavation height span ratio on the stability of a pseudo-collapse arch of surrounding rock under shallow buried loose surrounding rock, and rationally chooses the three-step method as the dominant construction method of tunnel construction under this geological condition. For the three-step construction method, the optimization study of the excavation height of the upper step is carried out, the relationship between the excavation height of the tunnel and the stress concentration area under the condition of shallow buried loose surrounding rock is revealed, the influence of surrounding rock stress release on the stability of the tunnel surrounding rock is explored, and the damage of tunnel rock mass caused by the stress concentration phenomenon is analyzed. It is determined that the optimal excavation height of the upper step is 0.4H under the geological conditions of the DS project in Sichuan province, China, under construction. This paper analyzes the influence of structural plane spacing on the stability of a tunnel collapse arch under shallow buried loose conditions and reveals the law that the smaller the structural plane spacing, the worse the self-bearing capacity of the collapse arch, and the higher the risk of engineering accidents such as rock collapse or even collapse in the tunnel, which effectively guides the safe construction of the tunnel under shallow buried loose geological conditions.

A study of XLPE insulation failure in power cables under electromagnetic stress

Underground cables with cross-linked polyethylene (XLPE) insulation are integral to medium voltage (MV) power transmission systems, ensuring continuous electricity supply amidst operational challenges and environmental conditions. However, the reliability of these cables can be compromised over time due to aging and installation-related factors, particularly at joints and terminations. This study offers a comprehensive analysis of how various defects, including spherical air voids, pinholes, and irregularities in semiconducting layers, affect electric field and potential distributions within cable end terminations using COMSOL Multiphysics software. Through detailed simulations, the study identifies significant variations in electric field strength caused by these defects, highlighting critical stress concentration areas. In this study, it assumed that the cable and termination have the same cross-section. By analyzing these simulations, the study provides insights into optimizing cable design and installation practices to enhance the reliability and lifespan of underground power transmission systems. This study introduces a novel approach by combining advanced COMSOL Multiphysics simulations with a detailed analysis of defect impacts on electric field distributions, offering new insights into stress concentrations and degradation at cable terminations. Simulation outcomes reveal significant variations in electric field strengths due to air voids and pinholes in cables and terminations: for 2 mm voids, up to 2.45×106 V mm−1 near the conductor and 56.5 V mm−1 at termination. These findings enhance the understanding of XLPE-insulated cable behavior under electromagnetic stress, providing a basis for mitigating failures and improving overall system performance.

Comparison of the biomechanical effects of the post-core crown, endocrown and inlay crown after deep margin elevation and its clinical significance

BackgroundThe purpose of this in vitro study was to compare and evaluate the stress distribution of maxillary first premolar residual crowns restored with post-core crowns, endocrowns and inlay crowns after deep margin elevation, to explore the fitting restoration for residual crowns using finite element analysis.MethodsA healthy complete right maxillary first premolar from a male adult was scanned by cone beam computed tomography (CBCT). The finite element model of the tooth was established by reverse engineering software such as Mimics, Geomagic and Hypermesh. On this basis, the residual crown model after deep margin elevation was made, and the experimental group models were divided into three groups, those restored with post core crowns, endocrowns and inlay crowns. Vertical and oblique static loads were applied to the experimental models to simulate the force on the tooth during mastication (the loading position was located in the central fossa of the occipital surface, and the load was 100 N) using Abaqus software.ResultsThe peak value and distribution of von Mises stress in each part of the experimental model were observed. After deep margin elevation, the peak dentin von Mises stresses were lower than the tensile strength of normal dentin in the post-core crown, endocrown, and inlay crown groups; the lowest stress results were found in the post-core crown group for the dentin, restoration, enamel, and deep margin elevation (DME) layers under vertical and oblique loading. In terms of stress distribution clouds, the peak stresses in the dentin tissue were located in the apical 1/3 of the root after postcore crown restorations for both loads, while stress concentrations were evident in the cervical and root areas after endocrown and inlay crown restorations; regardless of the load and restoration method, the corresponding stress concentration areas appeared at the junction of the DME and dentin tissue at the loading site of the restorations;ConclusionsPost-core crowns, endocrowns and inlay crowns can be used to restore residual crowns after deep margin elevation, and post-core crowns can better protect the residual tooth tissue.

Design optimization of lightweight automotive seatback through additive manufacturing compression overmolding of metal polymer composites

With the growing demand for enhanced automotive fuel efficiency and environmental sustainability, there is a need for lightweighting automotive components through innovative design and manufacturing processes. This study leverages a combination of numerical iterative design optimization and hybrid additive manufacturing–compression molding (AM-CM) technique for metal polymer composites to lightweight an automotive seatback. The AM-CM process enables robust mechanical interlocking between metals and composites, boasting high stiffness and strength with low overall density. Replacing metallic components with such metal polymer composites allows for comparable mechanical performance while significantly reducing the overall weight. First, the automotive seatback design space is reduced to critical load carrying regions using topology optimization and high stress concentration areas are identified using finite element analysis. Next, a lightweight metal polymer subcomponent is designed for a high stress concentration region. The full seatback frame with spatially heterogeneous material-specific design is then iteratively optimized to enable enhanced stiffness with minimal weight. Overall, the automotive seatback frame designed with location-specific metal, polymer, and metal polymer composite materials weighs 20% less than the metal-only design while exhibiting similar stiffness.

Comparison of Optical Properties and Fracture Loads of Multilayer Monolithic Zirconia Crowns with Different Yttria Levels.

Multilayer monolithic zirconia, which incorporates polychromatic layers that mimic natural tooth gradients, offers enhanced aesthetics and functionality while reducing debonding risks and improving fabrication efficiency. However, uncertainties remain regarding the fracture characteristics of multilayer monolithic zirconia crowns under occlusal loading, whether composed of uniform or combined yttria levels. The current study investigated how variations in yttria levels and thicknesses affected the optical properties and fracture loads of multilayer monolithic zirconia. Samples of multilayer monolithic zirconia in the Vita A1 shade were used, while employing 3Y (SZ) and 4Y + 5Y (AZ) yttria levels. The optical properties, including the color difference (ΔEWS) and translucency parameters (TP00), were measured using a digital colorimeter. The fracture loads were analyzed using a universal testing machine, and fractured surfaces were examined under a stereomicroscope. Statistical analyses assessed the impacts of the yttria levels and sample thicknesses on the optical properties. The ΔEWS values of SZ ranged 3.6 to 4.0, while for AZ, ΔEWS at 0.5 mm was 3.9 and <2.6 for other thicknesses. The TP00 values decreased with an increased thickness, with AZ generally exhibiting greater translucency than SZ. In the fracture load investigations, SZ (>1600 N) generally exceeded AZ (>1260 N), with fracture loads notably increasing with thickness, particularly for premolars (SZ > 3270 N, AZ > 2257 N). SZ predominantly exhibited partial and complete fractures, whereas AZ showed fewer non-fracture categorizations. Complete fractures began with dense, irregular cracks that extended outward to reveal smooth surfaces, while premolars subjected to higher loads exhibited concentric ripple-like structures. Partial fractures revealed radial textures indicative of areas of stress concentration. In summary, higher yttria levels were correlated with increased translucency, while variations in the fracture loads primarily stemmed from differences in the tooth position or thickness. Overall, multilayer monolithic zirconia incorporating combined yttria levels of 4Y + 5Y (AZ) offered high translucency, precise color matching, and substantial fracture resistance, rendering it highly suitable for aesthetic and functional dental applications.

Stress Characteristics and Mechanical Behavior of Rock Masses with an Opening under Complex Deep Underground Stress Conditions

In this study, the impact of principal stress states on the stress characteristics and initial failure of the rock mass surrounding a three-center arch opening was investigated using complex variable function methods and Discrete Element Method (DEM) numerical modeling. First, the mapping function of the opening was determined using the trigonometric interpolation method, and the influence of the number of terms in the mapping function on its accuracy was revealed. Based on this, the far-field stress state of the underground rock mass was characterized by the ratio of the minimum to maximum principal stress (λ) and the angle (β) between the principal stress and the vertical direction. This stress state was then converted into normal and shear stresses. Using complex variable function theory, the stress characteristics at the boundary of the opening under different stress states were analyzed. Finally, DEM numerical modeling was employed to study the initial failure characteristics at the boundary of the opening and its relationship with the stress distribution. The results indicate that the lateral pressure coefficient significantly affects the stability of the opening by influencing stress concentration around the surrounding rock. Low lateral pressure coefficients lead to tensile stress concentration at the boundary perpendicular to the maximum principal stress. As the coefficient increases, tensile stress decreases, and compressive stress areas expand. While the principal stress direction has a minor effect on stress concentration, it notably impacts stress distribution at the boundary. When λ &lt; 1.0 and β = 45°, stress distribution asymmetry is most pronounced, with the highest compressive stress. The early failure distribution aligns with stress concentration areas, validating the use of stress analysis in predicting opening stability and failure characteristics.