Pub Date : 2024-07-15DOI: 10.13052/ejcm2642-2085.3331
E. Ricketts, P. Cleall, Anthony Jefferson, Pierre Kerfriden, Paul Lyons
When conducting numerical analyses, boundary conditions are generally applied homogeneously, neglecting the inherent heterogeneity of the material being represented. Whilst the heterogeneity is often considered within the medium, its influence on the response at the boundary should also be accounted for. In this study, A novel approach to applying heterogeneous boundary conditions in the simulation of physical systems is presented, particularly focusing on moisture transport in unsaturated soils. The proposed method divides the surface into blocks or “macro-elements” and scales the boundary conditions based on the variation of material properties within these blocks. The principle of using overlapping kernel functions allows local effects to be considered, impacting neighbouring regions. To demonstrate the efficacy of the approach, a set of analyses were conducted that considered infiltration into a body of unsaturated soil, with various configurations of material properties and boundary conditions. The numerical simulations indicate that the application of scaled boundary conditions leads to a more natural and realistic response in the system. The applied method is independent on the numerical techniques employed in the simulation process, making it adaptable to existing computational codes, offering flexibility in capturing complex behaviours, and providing insights into how heterogeneity influences the system’s overall response.
{"title":"Influence of Spatially Varying Boundary Conditions Based on Material Heterogeneity","authors":"E. Ricketts, P. Cleall, Anthony Jefferson, Pierre Kerfriden, Paul Lyons","doi":"10.13052/ejcm2642-2085.3331","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3331","url":null,"abstract":"When conducting numerical analyses, boundary conditions are generally applied homogeneously, neglecting the inherent heterogeneity of the material being represented. Whilst the heterogeneity is often considered within the medium, its influence on the response at the boundary should also be accounted for. In this study, A novel approach to applying heterogeneous boundary conditions in the simulation of physical systems is presented, particularly focusing on moisture transport in unsaturated soils. The proposed method divides the surface into blocks or “macro-elements” and scales the boundary conditions based on the variation of material properties within these blocks. The principle of using overlapping kernel functions allows local effects to be considered, impacting neighbouring regions. To demonstrate the efficacy of the approach, a set of analyses were conducted that considered infiltration into a body of unsaturated soil, with various configurations of material properties and boundary conditions. The numerical simulations indicate that the application of scaled boundary conditions leads to a more natural and realistic response in the system. The applied method is independent on the numerical techniques employed in the simulation process, making it adaptable to existing computational codes, offering flexibility in capturing complex behaviours, and providing insights into how heterogeneity influences the system’s overall response.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-15DOI: 10.13052/ejcm2642-2085.3332
N. Wirawan, I. Abuzayed, M. Akbar, J. L. Curiel-Sosa
In the present work, a novel fast fracture plane orientation angle (FPOA) search algorithm for the 3D Puck failure criterion is proposed. In the 3D Puck failure criterion, a linear search algorithm is employed to calculate the maximum inter-fibre failure (IFF) value by iterating and comparing the IFF value for each FPOA. This process itself requires a substantial amount of computational resources. The proposed fast FPOA search algorithm is implemented to substitute the linear search algorithm in order to reduce the computational time. A total of 1×105 randomised stress cases are used to analyse the accuracy of the algorithm. The result was then compared with the Puck Stepwise Seach Method (SSM) and other fast FPOA search algorithms. The results show that the proposed fast FPOA search algorithm has better accuracy compared to the other fast FPOA search algorithms and is almost 5 times faster compared to the SSM algorithm by Puck. In addition, a subroutine contains the Puck failure criterion and the proposed fast FPOA search algorithm is embedded into a Finite Element Analysis (FEA) software to simulate the open-hole test (OHT) experiment on the composite material.
{"title":"Robust Fast Fracture Plane Orientation Angle Search Algorithm for Puck 3D Inter-Fibre Failure Criterion","authors":"N. Wirawan, I. Abuzayed, M. Akbar, J. L. Curiel-Sosa","doi":"10.13052/ejcm2642-2085.3332","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3332","url":null,"abstract":"In the present work, a novel fast fracture plane orientation angle (FPOA) search algorithm for the 3D Puck failure criterion is proposed. In the 3D Puck failure criterion, a linear search algorithm is employed to calculate the maximum inter-fibre failure (IFF) value by iterating and comparing the IFF value for each FPOA. This process itself requires a substantial amount of computational resources. The proposed fast FPOA search algorithm is implemented to substitute the linear search algorithm in order to reduce the computational time. A total of 1×105 randomised stress cases are used to analyse the accuracy of the algorithm. The result was then compared with the Puck Stepwise Seach Method (SSM) and other fast FPOA search algorithms. The results show that the proposed fast FPOA search algorithm has better accuracy compared to the other fast FPOA search algorithms and is almost 5 times faster compared to the SSM algorithm by Puck. In addition, a subroutine contains the Puck failure criterion and the proposed fast FPOA search algorithm is embedded into a Finite Element Analysis (FEA) software to simulate the open-hole test (OHT) experiment on the composite material.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141645030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-15DOI: 10.13052/ejcm2642-2085.3334
Alex J. Thomas, A. A. Asr
In this research, numerical modelling has been conducted to expand on existing research on cut-off walls mainly done by, [2] and [8]. This study is aimed at examining a unique geometric alignment that accommodates ‘branches’ on either side of a vertical 12-metre-deep cut-off wall and investigates the subsequent effect on seepage (discharge) and uplift force within the foundation of the dam. From the study conducted it had been observed that seepage was reduced with the inclusion of these branches whilst the cut-off wall was located at the centre base of a concrete dam. Subsequent testing of altering the branches’ angle presented a further reduction in seepage through the soil strata, with the optimum angle being around the range of 60–70 degrees. Further experimentation had shown that altering the position at two other distinct locations (dam’s heel and toe) has had a significant reduction in seepage with the heel being the most effective at reducing it. Uplift pressure has been evaluated to show that the best position for minimal uplift force is at the heel of the dam.
{"title":"Investigating Branched Cut-off Wall Effect on Seepage Using Numerical Modelling","authors":"Alex J. Thomas, A. A. Asr","doi":"10.13052/ejcm2642-2085.3334","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3334","url":null,"abstract":"In this research, numerical modelling has been conducted to expand on existing research on cut-off walls mainly done by, [2] and [8]. This study is aimed at examining a unique geometric alignment that accommodates ‘branches’ on either side of a vertical 12-metre-deep cut-off wall and investigates the subsequent effect on seepage (discharge) and uplift force within the foundation of the dam. From the study conducted it had been observed that seepage was reduced with the inclusion of these branches whilst the cut-off wall was located at the centre base of a concrete dam. Subsequent testing of altering the branches’ angle presented a further reduction in seepage through the soil strata, with the optimum angle being around the range of 60–70 degrees. Further experimentation had shown that altering the position at two other distinct locations (dam’s heel and toe) has had a significant reduction in seepage with the heel being the most effective at reducing it. Uplift pressure has been evaluated to show that the best position for minimal uplift force is at the heel of the dam.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141644669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-15DOI: 10.13052/ejcm2642-2085.3333
Alex Haskins, Carla McCabe, Ryan Keating, A. Lennon, Dominic Chandar
Discussed is a comparison of computational and experimental evaluations of passive drag during human swimming. Experimentally, ten trials were conducted per athlete at five chosen velocities, using a commercial resistance trainer to record the tension force in a rope during a streamline position tow test. The resistive force recorded was assumed equal to the passive drag force and an average value of passive drag was found across each tow test. Mean passive drag values measured during the tow test were agreed well with existing experimental data across the range of velocities used, varying between 20 N at 1 ms−1 up to 100 N at 2 ms−1. Computationally, using the immersed boundary method in OpenFOAM, basic geometry validation cases and streamline passive drag cases were simulated. Validation cases were completed on 2D cylinders and 3D spheres with the drag coefficient found at low and high Reynolds numbers, using the simpleFoam solver within OpenFOAM. Results tended to be slightly over predictive when compared with existing simulation and experimental data in literature. The accuracy of results could potentially be improved using a finer mesh and better quality geometries. The passive drag was also computed using OpenFOAM over a range of velocities, similar to the experiments, varying from 30 N at 1 ms−1 to 120 N at 2 ms−1. Drag forces computed using simpleFoam were over predictive when compared to existing literature and the completed experiments, likely due to the inaccuracy of the geometry used in the simulations. When results were compared to existing literature for swimmers not in a perfect streamline position, more similar to the geometry used in this study, results were in better agreement. The accuracy of the results could be improved using a better quality geometry in the correct position.
本文对人类游泳过程中被动阻力的计算和实验评估进行了比较。在实验中，使用商用阻力训练器在流线位置拖曳测试中记录绳索的拉力，以五种选定的速度对每位运动员进行了十次测试。记录的阻力被假定为等于被动阻力，每次拖曳测试都会得出被动阻力的平均值。在所使用的速度范围内，拖曳测试期间测得的平均被动阻力值与现有实验数据非常吻合，从 1 ms-1 时的 20 N 到 2 ms-1 时的 100 N 不等。在计算方面，使用 OpenFOAM 中的沉浸边界法模拟了基本几何验证案例和流线型被动阻力案例。在二维圆柱体和三维球体上完成了验证案例，使用 OpenFOAM 中的 simpleFoam 求解器在低雷诺数和高雷诺数下发现了阻力系数。与文献中现有的模拟和实验数据相比，结果倾向于略微偏高。使用更精细的网格和质量更好的几何图形可能会提高结果的准确性。使用 OpenFOAM 还计算了与实验类似的速度范围内的被动阻力，从 1 ms-1 时的 30 N 到 2 ms-1 时的 120 N 不等。与现有文献和已完成的实验相比，使用 simpleFoam 计算出的阻力预测过高，这可能是由于模拟中使用的几何形状不准确。如果将非完美流线位置（与本研究中使用的几何形状更相似）的游泳者的结果与现有文献进行比较，结果的一致性会更好。在正确的位置上使用质量更好的几何体可以提高结果的准确性。
{"title":"Estimation of Passive Drag in Swimming via Experimental and Computational Means","authors":"Alex Haskins, Carla McCabe, Ryan Keating, A. Lennon, Dominic Chandar","doi":"10.13052/ejcm2642-2085.3333","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3333","url":null,"abstract":"Discussed is a comparison of computational and experimental evaluations of passive drag during human swimming. Experimentally, ten trials were conducted per athlete at five chosen velocities, using a commercial resistance trainer to record the tension force in a rope during a streamline position tow test. The resistive force recorded was assumed equal to the passive drag force and an average value of passive drag was found across each tow test. Mean passive drag values measured during the tow test were agreed well with existing experimental data across the range of velocities used, varying between 20 N at 1 ms−1 up to 100 N at 2 ms−1. Computationally, using the immersed boundary method in OpenFOAM, basic geometry validation cases and streamline passive drag cases were simulated. Validation cases were completed on 2D cylinders and 3D spheres with the drag coefficient found at low and high Reynolds numbers, using the simpleFoam solver within OpenFOAM. Results tended to be slightly over predictive when compared with existing simulation and experimental data in literature. The accuracy of results could potentially be improved using a finer mesh and better quality geometries. The passive drag was also computed using OpenFOAM over a range of velocities, similar to the experiments, varying from 30 N at 1 ms−1 to 120 N at 2 ms−1. Drag forces computed using simpleFoam were over predictive when compared to existing literature and the completed experiments, likely due to the inaccuracy of the geometry used in the simulations. When results were compared to existing literature for swimmers not in a perfect streamline position, more similar to the geometry used in this study, results were in better agreement. The accuracy of the results could be improved using a better quality geometry in the correct position.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-06DOI: 10.13052/ejcm2642-2085.3321
Rayhan Prodhan, M. Ferdows, J. C. Misra, E. Tzirtzilakis, M. G. Murtaza
Theoretical and numerical investigation of an applied magnetic field on mixed convection flow of a biofluid through a vertical plate using contained heating or cooling is observed in this study. The mathematical formulation is that of the full Biomagnetic Fluid Dynamics (BFD) model which deals with on the ferrohydrodynamics (FHD) and magnetohydrodynamics (MHD) principle. In this work, the study is performed on a specific biofluid, viz. human blood. Assume that the magnetization very linearly with magnetic field strength, temperature dependency of dynamic viscosity and thermal conductivity is noticed. A system of non-linear equations with appropriate boundary condition is obtained by familiarizing suitable non-dimensional variables in the physical problem. For the numerical solution, we used finite difference method which is based on an efficient technique is applied in the problem. Computations for flow profiles, local skin friction coefficient and local heat transfer coefficient are performed with the magnetic parameter Mn, the viscosity/temperature parameter θr and the thermal/conductivity parameter S∗. The effect of the localized heating or cooling is examined. The computational results presented graphically and have been validated in an appropriate manner. The study reveals that the impact of a magnetic field for blood flow in arteries is found significantly. The results presented bear the promise of valuable applications in physiology, medicine and bioengineering.
{"title":"Non-Similar Analysis of Mixed Convection Biomagnetic Boundary Layer Flow Over a Vertical Plate with Magnetization and Localized Heating/Cooling","authors":"Rayhan Prodhan, M. Ferdows, J. C. Misra, E. Tzirtzilakis, M. G. Murtaza","doi":"10.13052/ejcm2642-2085.3321","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3321","url":null,"abstract":"Theoretical and numerical investigation of an applied magnetic field on mixed convection flow of a biofluid through a vertical plate using contained heating or cooling is observed in this study. The mathematical formulation is that of the full Biomagnetic Fluid Dynamics (BFD) model which deals with on the ferrohydrodynamics (FHD) and magnetohydrodynamics (MHD) principle. In this work, the study is performed on a specific biofluid, viz. human blood. Assume that the magnetization very linearly with magnetic field strength, temperature dependency of dynamic viscosity and thermal conductivity is noticed. A system of non-linear equations with appropriate boundary condition is obtained by familiarizing suitable non-dimensional variables in the physical problem. For the numerical solution, we used finite difference method which is based on an efficient technique is applied in the problem. Computations for flow profiles, local skin friction coefficient and local heat transfer coefficient are performed with the magnetic parameter Mn, the viscosity/temperature parameter θr and the thermal/conductivity parameter S∗. The effect of the localized heating or cooling is examined. The computational results presented graphically and have been validated in an appropriate manner. The study reveals that the impact of a magnetic field for blood flow in arteries is found significantly. The results presented bear the promise of valuable applications in physiology, medicine and bioengineering.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-06DOI: 10.13052/ejcm2642-2085.3323
Ming Li
This paper presents a comprehensive approach encompassing indoor experiments, theoretical analysis, and numerical simulations to investigate the durability of prestressed anchorage structures subjected to fatigue loads and corrosion. The study addresses the critical issue of gradual aging and damage caused by cumulative loads and corrosion, which ultimately leads to a decrement in structural durability. Through a rigorous analysis of the effects of fatigue load and corrosion on the performance of steel bars, numerical simulations were conducted to elucidate the failure mechanisms and variation patterns within the internal anchoring section. After subjecting steel bars to fatigue and corrosion tests for a defined duration, they were systematically categorized and exposed to varying fatigue tensile cycles in diverse acidic and alkaline environments. Employing the PFC2D program, a numerical model of the prestressed anchorage structure under the coupled effects of fatigue load, corrosion, and fatigue load was developed. This model allowed for a comparative analysis of the evolution of shear stress, axial stress, and displacement fields at the bolt-grout interface under two distinct conditions. The findings reveal the microscopic mechanisms underlying bond degradation at the bolt-grout interface under the synergistic impact of fatigue load and corrosion. The proposed methodology and experimental results demonstrate that geotechnical anchoring technology can effectively reinforce up to 70% of geotechnical structures, significantly reducing soil loss by approximately 80%. This research provides valuable insights into the durability of prestressed anchorage structures, paving the way for future improvements and optimizations.
{"title":"Study on Mechanical Characteristics and Durability of Prestressed Anchorage Structure of Rock and Soil under Fatigue-Corrosion Coupling Action","authors":"Ming Li","doi":"10.13052/ejcm2642-2085.3323","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3323","url":null,"abstract":"This paper presents a comprehensive approach encompassing indoor experiments, theoretical analysis, and numerical simulations to investigate the durability of prestressed anchorage structures subjected to fatigue loads and corrosion. The study addresses the critical issue of gradual aging and damage caused by cumulative loads and corrosion, which ultimately leads to a decrement in structural durability. Through a rigorous analysis of the effects of fatigue load and corrosion on the performance of steel bars, numerical simulations were conducted to elucidate the failure mechanisms and variation patterns within the internal anchoring section. After subjecting steel bars to fatigue and corrosion tests for a defined duration, they were systematically categorized and exposed to varying fatigue tensile cycles in diverse acidic and alkaline environments. Employing the PFC2D program, a numerical model of the prestressed anchorage structure under the coupled effects of fatigue load, corrosion, and fatigue load was developed. This model allowed for a comparative analysis of the evolution of shear stress, axial stress, and displacement fields at the bolt-grout interface under two distinct conditions. The findings reveal the microscopic mechanisms underlying bond degradation at the bolt-grout interface under the synergistic impact of fatigue load and corrosion. The proposed methodology and experimental results demonstrate that geotechnical anchoring technology can effectively reinforce up to 70% of geotechnical structures, significantly reducing soil loss by approximately 80%. This research provides valuable insights into the durability of prestressed anchorage structures, paving the way for future improvements and optimizations.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-06DOI: 10.13052/ejcm2642-2085.3322
Li Qing, Lu Hao
Shaoguan was hit by a extremely heavy rainstorm, and the mountain water catchment of Dabaoshan Tunnel in the southern section of Beijing Hong Kong Macao Expressway in Guangdong increased sharply. Due to the rapid rise of groundwater level, water and mud gushed at ZK141+227 of Dabaoshan, and serious water seepage occurred in other areas, bringing soil into the tunnel, which seriously hindered the safe passage of the tunnel. According to the on-site investigation of water and mud gushing, it was found that there were branches sandwiched in the mud gushing out, and at the same time, it was found that there was water leakage at the foot of some walls where drainage holes were added. Based on the fluid structure coupling mechanism, the seepage mechanism of highway tunnels was deeply explored, and the mechanical properties of tunnels under seepage were analyzed through experimental data and numerical simulation. The experimental results show that under the action of seepage, the stress distribution of the tunnel lining changes, and the phenomenon of local stress concentration is obvious. When the seepage pressure reaches 3.5 MPa, cracks appear in the tunnel lining, with a total of 5 cracks. The distribution of cracks is closely related to the seepage field. The numerical simulation further reveals the interaction mechanism between the seepage field and the tunnel structure, confirming the influence of the seepage field on the stability of the tunnel lining. When the seepage pressure increases to 4.0 MPa, the displacement change rate of the tunnel lining reaches 0.3 mm/m, and the maximum lining stress is 15.7 MPa. The purpose of this study is to propose a maintenance plan for highway tunnels to improve their safety. Consider the impact of seepage on tunnel structure and adopt effective waterproofing and drainage design. Further research on the seepage mechanism and tunnel mechanical properties is recommended to provide more reliable theoretical support for engineering applications.
{"title":"Analysis of Water Seepage Mechanism and Study on Mechanical Properties of Highway Tunnel Based on Fluid-Structure Coupling","authors":"Li Qing, Lu Hao","doi":"10.13052/ejcm2642-2085.3322","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3322","url":null,"abstract":"Shaoguan was hit by a extremely heavy rainstorm, and the mountain water catchment of Dabaoshan Tunnel in the southern section of Beijing Hong Kong Macao Expressway in Guangdong increased sharply. Due to the rapid rise of groundwater level, water and mud gushed at ZK141+227 of Dabaoshan, and serious water seepage occurred in other areas, bringing soil into the tunnel, which seriously hindered the safe passage of the tunnel. According to the on-site investigation of water and mud gushing, it was found that there were branches sandwiched in the mud gushing out, and at the same time, it was found that there was water leakage at the foot of some walls where drainage holes were added. Based on the fluid structure coupling mechanism, the seepage mechanism of highway tunnels was deeply explored, and the mechanical properties of tunnels under seepage were analyzed through experimental data and numerical simulation. The experimental results show that under the action of seepage, the stress distribution of the tunnel lining changes, and the phenomenon of local stress concentration is obvious. When the seepage pressure reaches 3.5 MPa, cracks appear in the tunnel lining, with a total of 5 cracks. The distribution of cracks is closely related to the seepage field. The numerical simulation further reveals the interaction mechanism between the seepage field and the tunnel structure, confirming the influence of the seepage field on the stability of the tunnel lining. When the seepage pressure increases to 4.0 MPa, the displacement change rate of the tunnel lining reaches 0.3 mm/m, and the maximum lining stress is 15.7 MPa. The purpose of this study is to propose a maintenance plan for highway tunnels to improve their safety. Consider the impact of seepage on tunnel structure and adopt effective waterproofing and drainage design. Further research on the seepage mechanism and tunnel mechanical properties is recommended to provide more reliable theoretical support for engineering applications.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-06DOI: 10.13052/ejcm2642-2085.3324
Mao Wei, Ruheiyan Muhemaier, Xuejun Liu, Shuqiang Chen, Yanjun Li
Based on the mutation theory, the paper studies the stability of loess slope, and discusses the loess slope in Yili region in Xinjiang. From the perspective of mechanics, the paper focuses on the influence of mutation phenomenon on the stability of loess slope, and deeply analyzes the mechanical mechanism in the mutation process. As an effective tool to study the phenomenon of discontinuous change, mutation theory has important applications in the stability analysis of loess slopes. By applying the mutation theory, the mutation characteristics of the loess slope in the Xinjiang Yili area were analyzed. In terms of mechanical mechanism, the stress distribution, deformation characteristics and the instability mode are discussed in detail. Through theoretical analysis and numerical simulation, it is found that when the slope stress reaches a certain critical value, mutation will occur, leading in a sharp decline of slope stability. Specific data show that in a typical loess slope in Yili area, when the stress reaches about 0.6 MPa, the slope changes, and the displacement instantly increases to more than twice the original, indicating that the slope has been in a state of instability. In the case study of loess slope in Yili, Xinjiang, the slope stability is comprehensively evaluated by combining field investigation to monitoring data and indoor test. By identifying and analyzing the mutation characteristics of the slope, it is found that there are widespread subsidence and disintegration problems in this area, which play a key role in the mutation process. The specific data show that the subsidence coefficient of the loess slope in Yili area is generally above 0.05, and the disintegration rate is more than 0.5% per hour. These factors jointly aggravate the mutation risk of the slope. Based on the above data analysis, the paper puts forward targeted disaster prevention and mitigation measures, including strengthening slope drainage, using appropriate reinforcement technology, etc. These measures aim to reduce the risk of mutation and improve the stability of the loess slope.
{"title":"Study on Stability Analysis Method of Loess Slope Based on Catastrophe Theory – A Case Study of Loess Slope in Yili, Xinjiang","authors":"Mao Wei, Ruheiyan Muhemaier, Xuejun Liu, Shuqiang Chen, Yanjun Li","doi":"10.13052/ejcm2642-2085.3324","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3324","url":null,"abstract":"Based on the mutation theory, the paper studies the stability of loess slope, and discusses the loess slope in Yili region in Xinjiang. From the perspective of mechanics, the paper focuses on the influence of mutation phenomenon on the stability of loess slope, and deeply analyzes the mechanical mechanism in the mutation process. As an effective tool to study the phenomenon of discontinuous change, mutation theory has important applications in the stability analysis of loess slopes. By applying the mutation theory, the mutation characteristics of the loess slope in the Xinjiang Yili area were analyzed. In terms of mechanical mechanism, the stress distribution, deformation characteristics and the instability mode are discussed in detail. Through theoretical analysis and numerical simulation, it is found that when the slope stress reaches a certain critical value, mutation will occur, leading in a sharp decline of slope stability. Specific data show that in a typical loess slope in Yili area, when the stress reaches about 0.6 MPa, the slope changes, and the displacement instantly increases to more than twice the original, indicating that the slope has been in a state of instability. In the case study of loess slope in Yili, Xinjiang, the slope stability is comprehensively evaluated by combining field investigation to monitoring data and indoor test. By identifying and analyzing the mutation characteristics of the slope, it is found that there are widespread subsidence and disintegration problems in this area, which play a key role in the mutation process. The specific data show that the subsidence coefficient of the loess slope in Yili area is generally above 0.05, and the disintegration rate is more than 0.5% per hour. These factors jointly aggravate the mutation risk of the slope. Based on the above data analysis, the paper puts forward targeted disaster prevention and mitigation measures, including strengthening slope drainage, using appropriate reinforcement technology, etc. These measures aim to reduce the risk of mutation and improve the stability of the loess slope.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-27DOI: 10.13052/ejcm2642-2085.3312
Zhifang Ma, Xiaoguang Guo
To ensure the safety and stability of high-speed rail lines and reduce external interference, it is essential to build a large number of elevated bridges. These elevated bridges account for a considerable proportion of the total length of high-speed rail lines. However, when high-speed rail lines pass through earthquake prone areas, the likelihood of earthquakes occurring when trains pass through bridges increases significantly. Therefore, it is necessary to study the dynamic response of bridge structures under earthquake action to ensure the safety of bridges during train operation and operation. The optimization scheme proposed in this article has undergone moderate impact tests, and the results show that the maximum lateral displacement of the bridge can reach 124 mm, while the maximum vertical acceleration is 5.16 m/s2, Exceeded the safety limit of 0.35 g. Through the analysis of train derailment coefficient, wheel load reduction rate, lateral sway force, lateral and vertical acceleration, and Spelling comfort index, we have come to the conclusion that bridges can ensure the safety of train operation in the absence of earthquakes and small earthquakes, and can also maintain certain stability under medium and large earthquakes. These research results have important guiding significance for the design and construction of high-speed rail lines. By optimizing the bridge structure and adopting relevant technical measures, the seismic disaster resistance of high-speed rail lines can be further improved, ensuring the safety and comfort of passengers during travel. At the same time, these research results also provide useful reference and inspiration for the construction and improvement of future high-speed rail lines.
为了确保高铁线路的安全性和稳定性，减少外部干扰，必须修建大量的高架桥。这些高架桥在高速铁路线总长度中占有相当大的比例。然而，当高速铁路线经过地震多发地区时，列车通过桥梁时发生地震的可能性会大大增加。因此，有必要研究桥梁结构在地震作用下的动态响应，以确保列车运行和运营过程中的桥梁安全。本文提出的优化方案经过中度冲击试验，结果表明桥梁的最大横向位移可达 124 mm，最大竖向加速度为 5.16 m/s2，超过了 0.35 g 的安全限值。通过对列车脱轨系数、轮载减载率、横向摇摆力、横向和竖向加速度、拼装舒适度指数等指标的分析，得出桥梁在无震和小震情况下能保证列车运行安全，在中震和大震情况下也能保持一定稳定性的结论。这些研究成果对高铁线路的设计和建设具有重要的指导意义。通过优化桥梁结构和采取相关技术措施，可以进一步提高高铁线路的抗震防灾能力，确保旅客出行的安全性和舒适性。同时，这些研究成果也为未来高铁线路的建设和完善提供了有益的参考和启示。
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Special mechanical environment, the environmental temperature or stress transformation easily to the final mechanical properties of the bridge components performance changes. The impact of the cold zone environment on the plate rubber-bearing beams is the object of study, Jining Road refined mechanics finite element analysis of the structural dynamic response study under seismic action. The results show that low temperature leads to bearing friction slip and material parameter changes, which affects the self-oscillation frequency and seismic susceptibility of the bridge. Due to the temperature-induced changes in the material properties and mechanical properties of the bearings, the first principal period of the bridge increases by 3% at high temperature for the EH and decreases by 19% at low temperature for the EL when compared to the first principal period under normal temperature conditions. Under different extreme temperature conditions, the fundamental period of the bridge is longitudinal, and the effective mode vibration participation mass is more than 90%. The maximum crossover frequency VALmax reaches 75.6 dB. Compared with room temperature, the bearing stress increased by 27.6% to 45.5%. The effect of EL stress change should be considered in the design of bridges in the alpine region.
{"title":"Frictional Slip and Incremental Dynamic Analysis of Plate-rubber Bearing Continuous Girder Bridge by Ambient Temperature in Cold Region","authors":"Hongwei Jiang, Qiao Wei, Xiaojian Xu, Guangtao Xin","doi":"10.13052/ejcm2642-2085.3313","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3313","url":null,"abstract":"Special mechanical environment, the environmental temperature or stress transformation easily to the final mechanical properties of the bridge components performance changes. The impact of the cold zone environment on the plate rubber-bearing beams is the object of study, Jining Road refined mechanics finite element analysis of the structural dynamic response study under seismic action. The results show that low temperature leads to bearing friction slip and material parameter changes, which affects the self-oscillation frequency and seismic susceptibility of the bridge. Due to the temperature-induced changes in the material properties and mechanical properties of the bearings, the first principal period of the bridge increases by 3% at high temperature for the EH and decreases by 19% at low temperature for the EL when compared to the first principal period under normal temperature conditions. Under different extreme temperature conditions, the fundamental period of the bridge is longitudinal, and the effective mode vibration participation mass is more than 90%. The maximum crossover frequency VALmax reaches 75.6 dB. Compared with room temperature, the bearing stress increased by 27.6% to 45.5%. The effect of EL stress change should be considered in the design of bridges in the alpine region.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140377199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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