Stress Concentration Area Research Articles

Parametric design and performance evaluation of gyroid triply periodic minimal surface preparation by LCD photopolymerization

In this paper, the Gyroid triply periodic minimal surface is prepared by liquid crystal display photopolymerization technology, and 10 models of the periodic parameter T in [1/5, 2] are designed. Using the method of finite element method and experimental verification, when T = 1/3, there are fewer stress concentration areas on the Gyroid surface, the number of grids is moderate, the compression crush rate is the smallest, and the porosity error is reasonable. Through the microscopic morphology, it is found that the surface, after printing, forms gear shape and resin residue so that the actual volume is larger than the theoretical volume, and the porosity is minor. Keeping periodic parameter T = 1/3 and porosity of 50%, four kinds of Gyroid surface structures were designed by changing the parameter surface offset, wall thickness, offset thickness, and gradient arrangement. The effects of different loading directions on its mechanical properties, deformation behavior, and energy absorption were discussed through compression experiments. The results show that the vertical load is applied to form a fault zone from the upper left angle to the lower right angle of 45°, and the parallel load is applied to create a fault zone from the upper right angle to the lower left grade of 45°. When the load is used in the vertical direction, the energy absorption and energy efficiency of the surface offset Gyroid surface are the largest. When the load is applied in the parallel order, the energy absorption curves of the four structures change similarly, and the deformation amplitude of the wall thickness Gyroid surface during the compression process is relatively stable. The energy efficiency of gradient arrangement Gyroid surface increases fastest in the compaction stage.

Influence of Scanning Strategy and Post-Treatment on Cracks and Mechanical Properties of Selective-Laser-Melted K438 Superalloy

The feasibility of manufacturing high-performance components with complex structures is limited due to cracks in some superalloys fabricated by selective laser melting (SLM). By controlling the main process parameters such as scanning strategy, the adverse effects of cracks can be effectively reduced. In this paper, the effects of two different SLM scanning strategies with island and ‘back-and-forth’ and post-heat treatment on the cracks and mechanical properties of selective-laser-melted (SLMed) K438 alloy were investigated. The results show that the SLM method of the ‘back-and-forth’ scanning strategy had better lap and interlayer rotation angles and a more uniform distribution of laser energy compared with the island scanning strategy. The residual stress accumulation was reduced and crack formation was inhibited under this scanning strategy owing to the cooling and shrinkage process. In addition, the dislocation motion was hindered by the formation of uniformly dispersed MC carbides and γ’ phases during the SLM K438 alloy process, which resulted in the density of the as-built SLMed K438 alloy being up to 99.34%, the hardness up to 9.6 Gpa, and the tensile strength up to 1309 MPa. After post-heat treatment, the fine secondary γ’ phases were precipitated and dispersed uniformly in the Ni matrix, which effectively improved the Young’s modulus and tensile strength of the alloy by dispersing the stress-concentrated area.

Effects of fissure length and angle on the fracture modes of 3D printed teeth model: Insights from DIC-based fracture tests and meshless numerical simulations

To investigate the influences of teeth fissure properties on their failure modes, 3D Printing technology is used to prepare the teeth models. The strain distributions of the teeth model surfaces at each moment of the loading processes are obtained by the DIC technique. And the progressive failure processes as well as the stress distributions of the teeth models are simulated by the improved Smoothed Particle Hydrodynamics (SPH) Method. Experimental results show that under the action of the steel ball, the teeth models mainly produce two types of cracks: The tensile cracks along the pre-existing fissures and the shear cracks along both sides of the teeth model. The existence of prefabricated fissures greatly reduces the peak strength of the teeth models. Compared with the circumstances containing no pre-existing fissures, the peak strength of d = 1 cm, d = 2 cm and d = 3 cm decreases by 22.33%, 31.79% and 18.94%, respectively, and the peak strength of θ = 30°, θ = 45°, θ = 60° decreases by 10.78%, 44.01% and 34.3%, respectively. Numerical results show that the initiations of tensile cracks are induced by the high tensile stress concentrations at the pre-existing fissure tips, while the shear cracks are caused by the high tensile stress concentrations in the low tensile stress concentration areas after the initiation of tensile cracks. The research results can provide some references for the understandings of teeth failure mechanisms as well as the applications of SPH method into teeth crack propagation simulations.

Investigating Si (100) surface patterns as well as electrical states through integrating molecular dynamics simulations with density functional tight binding at atomic level

The present work performs molecular dynamics simulations within model potential’s framework to investigate surface atoms’ rearrangements, loading states, and stress distribution in Si (100) surface on heating, and then single point energy calculations for the obtained atomic packing structures of Si substrates are used to obtain electrical information through self-consistent charge density functional tight binding approach. From analysis of Lode-Nadai parameters, atomic stress, visually packing images, Mulliken charges of atoms, Mulliken electron populations on atomic orbitals, differential charge densities, and chemical potentials for substrates, the knowledge of surface patterns, micro-loading states on the atoms and electrical states are obtained. The simulation results show the positions of vacancies have a significant impact on the rearrangements of the surface atoms. The appropriate selection of vacancy positions could be helpful in designing patterns of Si (100) surface. The vacancies in the subsurface or deeper atomic layers present migrations, where the migrations are more likely to occur at higher temperatures. There are stress concentration area and apparent charge transfers for the atoms forming dimers and neighboring atoms around the vacancies, and the differential charge densities in the surface atoms also present significant differences. These substrates with different surface patterns have different chemical potentials.

Study on rock-breaking mechanism and bit adaptive characteristics under the action of claw-toe impregnated diamond bit

In order to overcome the ingrained belief that the impregnated diamond bit primarily achieves rock-breaking via grinding and micro-cutting and to have a better understanding of the drilling mechanism of the bit, in this work, aiming at the inherent weakness of rock cracks, a claw-toe impregnated diamond bit (CTB) with a self-regenerative structure is innovatively designed. The concept is that the structure of the bit can actively induce the development of cracks inside the rock or create cracks in the dense rock. Through simulation, the differences in hole bottom morphology, drilling efficiency, rotational speed, torque and rock-breaking vibration between conventional bit (CB) and CTB (CTB with two sets of tooth units (CTB-2) and CTB with three sets of tooth units (CTB-3)) are analyzed, and the crack propagation and stress-strain field distribution characteristics of rock are compared when the tooth units of bit (TUBs) press into rock and cause initial damage to rock. Through field tests, the superiority of the claw-toe impregnated diamond bit (CTB) and its rock-breaking mechanism is verified. Compared with the conventional bit (CB), the simulation results show that the claw-toe impregnated diamond bit (CTB) can achieve efficient drilling with smaller rock-breaking torque, more stable rotational speed, and a more apparent shear effect on rock. The mean vibration reaction force of the claw-toe impregnated diamond bit with two sets of tooth units (CTB-2) and claw-toe impregnated diamond bit with three sets of tooth units (CTB-3) increases by 0.78 times and 0.43 times, respectively, and the mean rock-breaking torque decreases by 10.66% and 21.81%, respectively. The structure of the claw-toe impregnated diamond bit (CTB) can force rock to produce more tensile stress concentration areas, induce rock crack initiation, and accelerate rock failure. Field tests show that the service life of the claw-toe impregnated diamond bit with three sets of tooth units (CTB-3) is 1.9 times longer than the mean service life of the conventional bit (CB). Furthermore, the claw-toe impregnated diamond bit (CTB) has obvious structural advantages: it will self-sharpen its structure, maintain its best drilling structure in subsequent drilling, and tear up rock, resulting in better drilling performance.

Influence of different heat treatments on fracture behavior of rolling element bearing steels

Rolling element bearings (REB), one of the critical components of mechanical power transmissions, operate under high contact loads concentrated over small volumes of material. The damage caused by fatigue to REBs happens in two stages: the initiation of cracks and the propagation of cracks from areas of stress concentration. To select bearing steels for different applications, it is important to have knowledge about the material’s ability to resist fracture. This study presents results from an experimental investigation of bearing steels manufactured using different heat treatments. Steels were induction-hardened, carburized, and through-hardened, generating varying microstructures. Fracture mechanics tests were conducted using ASTM standards. The data generated is useful for predicting crack initiation and growth behavior under different loading conditions. Microscopic-level investigations are also presented to discern the fracture mechanisms associated with different microstructures.

Effect of δ–ferrite and strain-induced martensite on hydrogen embrittlement of STS 308 L and STS 316 L all-weld metals

The susceptibility of multipass flux-cored arc welds of STSs 308 L and 316 L to hydrogen embrittlement (HE) was investigated at various temperatures. Cracks predominantly initiated and propagated along the δ-ferrite in the interdendritic region at 25 °C. δ-ferrite served as preferred hydrogen trap sites, and the δ/γ boundary became the stress concentration site. At −100 °C, STSs 308 L and 316 L exhibited high susceptibility to HE owing to strain-induced martensite formation, providing additional hydrogen trap sites and dislocation accumulation. Despite strain-induced martensite actively transformed at −196 °C, the HE disappeared owing to the sluggish diffusion of hydrogen to stress-concentrated areas.

Analysis and Prevention of Rock Burst Risk of Working Face under the Influence of Continuous Irregular Triangular Coal Pillar Stress Concentration Area.

Irregular coal pillars inevitably appear in the layout of the current long-wall mining method, which easily forms stress concentrations and becomes a heavy disaster area of rock burst. In order to solve the impact risk of irregular coal pillar working face, it is necessary to study the instability mechanism of the coal pillar and put forward effective prevention and control measures. Based on the research background of 14320 working face of the Dongtan Coal Mine in the Yanzhou mining area of China, this paper studies the prediction and prevention of rock bursts in this kind of coal pillar by means of theoretical calculation, numerical simulation, engineering analogy, and field monitoring. The results show that (1) the absolute stability of coal pillar is that the width of coal pillar B reaches twice the support pressure of 2L, and the possibility of instability from large to small is coal pillars 2, 5, 3, 1, and 4. (2) The ratio of coal pillar strength to its average load determines the stability coefficient of the coal pillar, and it is judged that coal pillars 1 and 4 are in a stable state, coal pillars 3 and 5 are in a limit equilibrium state, and coal pillar 2 is in an unstable state. The numerical simulation shows that the maximum stress value inside the coal pillar during the mining process is basically consistent with the theoretical calculation of the bearing strength of the coal pillar. (3) The new evaluation method is used to evaluate the rock burst risk degree of the working face roadway: 156.75 m is a strong rock burst risk zone, 728.18 m is a medium rock burst risk zone, and 176.88 m is a weak rock burst risk zone. (4) Regional prevention and local prevention measures are proposed for the risk of rock burst in the roadway, which reduces the stress concentration of the coal pillar. It is verified that the pressure relief effect is remarkable, and the safe mining of such an irregular coal pillar working face is completed, which provides a solution for studying and solving such rock burst risk.

Energy absorption and mechanical performance of 3D printed Menger fractal structures

Porous structures fabricated through selective laser melting (SLM) are prospective candidates for high-energy-absorbing applications due to their tuneable mechanical properties. The Menger Fractal Cube (MFC) is a unique fractal cube formed through iterative removal of smaller cubes from a larger one. It is distinguished by its intricate self-similar pattern of voids and cubes repeating at diminishing scales, resulting in a lightweight and highly complex structure. Using AlSi7Mg, compression experiments and simulations investigated MFCs with three different orders. Digital image correlation was used to identify the stress concentration areas within the elastic deformation range of MFCs, and the relationship proposed in the Gibson-Ashby model was successfully implemented. The nature of the collapse, fracture mechanism, and energy absorption behaviour were investigated with the plateau and densification region deformation profiles. The highest level of specific energy absorption was recorded in third-order MFC, whereas the maximum densification displacement and energy absorption efficiency were observed in the fourth-order MFC. The test results also showed that the peak force decreased with increasing fractal order, suggesting that high-order MFCs can be employed as protective sacrificial structures that reduce force transmission to the protected structures. In brief, MFCs demonstrate outstanding energy absorption properties and hold promising potential for a wide range of structural applications that require energy-damping characteristics.

Continuous carbon fiber 3D printing partitioning method based on stress distribution

3D printing of continuous carbon fiber composites presents a need for the directivity of fiber distribution. For parts with actual working conditions, the stress distribution of the same part under the same stress condition is different, but the existing partitioning algorithm mainly fills the path of the subregion according to the shape of the part, and does not combine the working condition of the part. To solve this problem, a partitioning algorithm based on stress contour density is proposed. Based on the results of finite element analysis, the stress contour of the parts is obtained, and the stress concentration area is partitioned by calculating the stress contour density. The stress concentration area is filled with a more suitable path to improve the performance of the parts.

Key parameters of gob-side entry retaining by roof cutting in close-distance seam group

During the process of close-distance seam group mining, the coal pillar in the upper coal seam is a stress-concentrated area, which leads to a loss of stability of the roadway during mining of the lower coal seam. This lack of stability introduces great safety hazards to coal mines. To solve the problem of stress concentration of coal pillars, the method of gob-side entry retaining by roof cutting is proposed to remove the coal pillar. In this study, FLAC3D was used to analyze the depth and angle of pre-split blasting. LS-DYNA was used to analyze the spacing of the blasthole. Using the methods of theoretical analysis and numerical simulation, we determined that the optimal depth of the pre-split blasting was 6 m, the optimal angle for pre-split blasting was 15°, and the optimal spacing of the blasthole was 500 mm. A field test was carried out in the 1010201 ventilation roadway of the Yuwang Coal Mine, China. The on-site peeping results showed that when the spacing of the blasthole is 500 mm, connecting cracks can form under the action of blasting stress. After the working surface is mined, the roof strata could collapse and fill the gob over time when the depth and angle of the pre-split blasting are 6 m and 15°, respectively.

Role of foliation occurrence and stress orientation on asymmetric failure in foliated rock tunnel: insight from numerical simulation

The failure problem of deep-buried foliated rock tunnel is very prominent, which often presents asymmetry. Moreover, this failure is closely related to foliation occurrence and in-situ stress, and its mechanism is still unclear at present. In this study, a deep buried foliated rock tunnel in a hydropower station was taken as a case, and its failure mechanism was studied by using CASRock software embedded with three-dimensional equivalent continuous mechanical model of foliated rock. On this basis, the relationship and mechanism between the failure of deep-buried foliated rock tunnel and foliation occurrence, in-situ stress and tunnel axis were systematically studied. The results indicate that when the angle between the foliation strike and the tunnel axis (γ) is small, the surrounding rock will experience a larger range of failure. As the γ increases, the depth and degree of failure will significantly decrease. The dip angle of foliation (θ) and the orientation of maximum principal stress determine the failure location of tunnel section. When designing foliated rock tunnels, the angle between the foliation strike and the tunnel axis (γ) should be minimized as much as possible. When the γ is small, more attention should be paid to the orientation of the stress concentration area and its angle with the foliation on the tunnel section after excavation, and support should be strengthened for the small angle parts. This study has important guiding significance for the design, understanding of failure mechanisms, and disaster prevention and control of foliated rock tunnels.

Ultimate Load-Bearing Capacity and Sustainable Performance of Pile Foundations of Yanji Suspension Bridge in Fault Zone Based on Refined Geological Model

Pile foundation is the most important foundation type of long-span bridges, of which the ultimate load-bearing capacity affects the safety and sustainable performance of bridges. When constructing large-span bridges, the bridge site may be close to the adjacent fault zones, which seriously affects the safety and long-term performance of pile foundations, causing the failure and unsustainability of long-span bridges in their life-cycle service life. At present, there are no engineering design rules or methods for assessing the load-bearing capacity of the pile foundation near the fault zones. To study the influence of the fault zone on the loading-bearing capacity and sustainable performance of pile foundations, triaxial compression tests were carried out on the mylonite at the Yanji suspension bridge site near the Xiangfan–Guangji fault zone in Hubei Province. The mechanical properties of mylonite were reflected by the Mohr–Coulomb yield criterion, and a topographic and geological modeling method based on the multi-platform was established. Then, the ABAQUS finite element software was used to study the deformation, stress, failure modes, and sustainable performance of the pile foundation under different bridge load levels, analyze the safety of the pile foundation in the fracture zone, and summarize the ultimate bearing characteristics of the pile foundation. The results show that the whole pile and surrounding rock are basically elastic under the pressure of the designed load, the plastic zone of the pile foundation is mainly concentrated at the pile bottom, and the shear stress concentration zone of the pile is mainly manifested in the joint of the cap and pile and the interface between soft and hard rock. When the load is increased to 4 times the designed load, the stress concentration area of the pile body gradually shifts upward from the pile bottom, and the surrounding rock at the bottom forms an “X-shaped” shear failure zone. After 100 years of operation, the maximum compressive stress of piles reaches 28.6 MPa, which is 120% higher than that at the beginning of the bridge construction, indicating that the sustainable performance of the piles can withstand the effect of the fault zone over the designed service years.

Mechanism of Stratum Instability and Dynamic Deformation under Discontinuous Boundary Conditions

A fault disrupts the continuity of the rock strata in a mining area. To study the law governing the fracture of overlying strata in mining areas under discontinuous boundary conditions, the overlying strata were redefined and grouped based on the activity characteristics of each rock layer during the overall movement of the overlying strata. The activity patterns of different layers of the fault were obtained through the movement and failure forms of each group of rock layers. The relationship among the size of the coal pillar at the boundary of the fault, the dip angle of the fault, and the movement angle of the rock strata was considered. A model of the spatial relationship between the overlying rock movement zone of the quarry and the fault surface was established. The limit equilibrium equations of the key layer in the fault zone before breaking were established based on the tensile strength of the rock layer. In addition, the mechanical slip instability criterion and the deflection instability criterion of the discontinuous-boundary rock mass are given herein. Based on a field case, a double criterion was used to determine the initiating activated rock layers of the fault in the cases where the fault dip was smaller than the rock movement angle. Rock movement during excavation was simulated by similar simulation tests, and different levels of rock movement patterns in the boundary fault zone were focused on monitoring and analyzing. The stress and displacement changes in different rock layers in the fault zone were analyzed with numerical simulation results. The results show the following: if the dip angle of the fault is smaller than the movement angle of the rock layer, the delamination space of the fault surface is mainly distributed in the bending and sinking zone of the overlying rock; with an increase in the working-face advancement distance, the vertical pressure of the upper part of the fault gradually decreases, and the stress-concentration area in the middle and lower part of the fault gradually increases; the rock layer of the upper part of the fault, which is mainly composed of the key stratum, is the main area of activation of the fault.

Geodynamic Mechanism of the Evolution of the South China Sea Basin: Simulation Based on the Finite Difference Method

The South China Sea is in the convergence zone of the Pacific plate, the Indo-Australian plate, and the Eurasian plate. Its formation and tectonic evolution were influenced by continental margin spreading and plate interaction between the three plates and their microcontinents. It has a complex geodynamic background. To understand how continents break up to form ocean basins, the South China Sea Basin is taken as an example to study the dynamic mechanism of its formation and evolution and the driving force of seafloor spreading, so as to understand the relationship between oceanic–continental lithosphere plates. The South China Sea basin’s opening mechanism and its principal factors of control remain controversial. To explore the influence of different extension rates, we summarized the different genesis mechanisms of the South China Sea, and combined with the tectonic section of the basin, the numerical simulation was obtained based on the finite difference method. The results obtained from numerical simulations show that the rapid extension rate was one of the important factors in the asymmetric expansion of the model, with other factors such as the thickness and rheological properties of the lithosphere held constant. The lithospheric mantle continued thinning in the stress concentration area, with the crust being pulled apart before the lithospheric mantle, eventually forming an ocean basin corresponding to the east sub-basin. However, when the extension rate was low, the model expanded almost symmetrically, and the lithosphere thinning occurred at a slow rate. The simulation results confirm that, compared with the southwest sub-basin of the South China Sea, the spreading rate of the east sub-basin was even higher. We believe that the subduction of the proto-South China Sea played a crucial role in the opening of the South China Sea, providing a more reasonable mechanism. The opposite movement of the Indo-Australian plate and Kalimantan may have inhibited the formation of the southwest sub-basin of the South China Sea, resulting in a later spreading of the southwest sub-basin than the east sub-basin, as well as a lower rate of spreading than the east sub-basin.

Mechanical response analysis of the wide-chord hollow fan blade considering the fluid–structure interaction

The aero-engine wide-chord hollow fan blade with a cavity stiffener structure can effectively reduce the weight and greatly increase the rotational speed. However, during the high-speed rotation process of the hollow fan, there is a strong coupling effect between the solid domain of the blade and the incoming air. This effect leads to a certain deformation of the rotor blade, which has a large impact on the structural strength of the blade. Aiming at the problem of the fluid–structure interaction in its operation, the finite-element method was used to simulate the two-layer structure of the TC4 titanium alloy wide-chord hollow fan blade. The centrifugal force and fluid–structure coupling effect were considered when carrying out the research on the structural mechanical characteristics of the blade. The results show that the maximum equivalent stress of the blade considering the fluid–structure coupling effect is 508 MPa at the rotational speed of 2,900 r/min, which is approximately 18% higher than the maximum stress when only the centrifugal force is considered. This phenomenon indicates that the effect of aerodynamic force on the blade stress cannot be ignored. The stress concentration area of the blade is located in the third stiffener from the leading edge and near the root of the blade, and the aerodynamic force has a more significant effect on the radial stress distribution of the blade. Further analysis of the equivalent stress distribution along the blade tip direction shows a trend of first increasing and then decreasing. The maximum equivalent stress appears at a distance of 30 mm up to the bottom of the stiffener.

Research on Hydraulic Fracturing Pressure Relief and Improvement Permeability Technology of the Soft Coal Seam Roof.

Aiming at the characteristics of low permeability and large gas content of deep soft coal seam, hydraulic fracturing pressure relief and improvement permeability technology of the roof are proposed. FLAC3D was used to invert the roof hydraulic fracturing of the soft coal seams. On this basis, the dynamic evolution characteristics of permeability before and after fracturing were given by the COMSOL multiphysics software. Finally, roof hydraulic fracturing technology was applied on the site. The results show that after the hydraulic fracture of the roof, the peak stress on both sides of the roadway is reduced by 1.7 MPa, the peak stress concentration in front of the roadway is reduced by 2.2 MPa, the stress concentration range is reduced, and the stress is effectively transferred to the deep part of the roadway. After fracturing, the permeability of the stress concentration area increased by 2.18 times, the permeability of the original rock stress area increased by 1.84 times, and the gas fluidity improved. After roof hydraulic fracturing, the occurrence of a coal cannon decreases from 2 to 4 times per 1 m driving to 0 to 1 times, and the phenomenon of a coal cannon at the working face decreases significantly. The concentration of the return air flow is reduced from 0.5-0.9% to 0.2-0.4%. The results of this study have a guiding role in taking the corresponding measures for gas disaster prevention and control.

Investigation on Cracking Cause of Drill Pipe Joint Used in an Ultra Deep Well

The drill pipe joint cracked during service, resulting in joint failure. The geometric dimensions of thread, chemical composition and microstructure of the drill pipe joint were tested. The geometric dimensions, chemical composition and microstructure were found to comply with the standard requirements. The whole macroscopic fracture didn’t show obvious corrosion product. The tensile properties, Charpy impact properties, and Brinell hardness met the standard requirements. Microstructure of fracture was analyzed, which showed a typical erosion micromorphology with parallel arranged fatigue strips. Through simulation analysis, it was found that the location of cracking was the stress concentration area. The failure mechanism of the drill pipe joint was revealed. The stress concentration led to fatigue cracking at the drill pipe joint. After the fatigue crack penetrated through the wall thickness, the drilling fluid leaked from the inner wall to the outer wall. The flow rate of the leaking drilling fluid is significantly increased. And it is sprayingly leaked, which further leads to fan-shaped erosion damage of the cracked surface from the inner wall to the outer wall.

RESEARCH AND OPTIMIZATION OF SPORT UTILITY VEHICLE AERODYNAMIC DESIGN

Drag and lift are two important parameters to evaluate a vehicle’s aerodynamic performance. Aerodynamic resistance (drag force Fd) prevents the movement of the vehicle and has a value proportional to the square of the velocity. That is, when the speed increases twice, the aerodynamic drag will increase fourfold. This article presents a plan to design a sport utility vehicle model with improved aerodynamics by using Ansys Fluent software to analyze pressure distribution areas that affect aerodynamics and the body. Based on the results obtained, the areas of stress and maximum pressure concentration have been identified. From this, a plan to improve the vehicle’s exterior design has been proposed. After many iterations of the design and model optimization process, the aerodynamic drag coefficient CD was reduced by 3.06% compared to the original model. The revised design option is equipped with an airflow diffuser under the vehicle; the lifting resistance coefficient has been reduced from 0.0902 to 0.038, equivalent to 58.2%. The new proposed design of the model has reduced the vehicle’s frontal drag by 2.04%. The research results have determined the aerodynamic coefficients CD and CL of the model car. Based on the results received, it is possible to compare them with the manufacturer’s announced parameters and propose new design options that still ensure aesthetics.

Using finite element modeling to predict stress concentration factors in tubular T, Y and K joints

Tubular offshore structures are commonly assembled using welded joints, creating areas of stress concentration and potential fatigue failure. This study focuses on tubular T, Y and K joints, a common offshore structural component. Finite element modeling is used to predict stress concentration factors (Kt) for various loading conditions on the T, Y and K joints. The goal is to calculate Kt values and compare them to existing theoretical solutions from literature. Additionally, the influence of different loading modes (tension, bending) on the Kt values is investigated. By using advanced modeling techniques, this work aims to provide new insight into the behavior of tubular T, Y and K joints connections under realistic offshore loading conditions. The results can help improve design standards and fatigue life predictions for these critical structural joints.