Local soil conditions play a crucial role in shaping ground surface responses and impacting the intensity of ground shaking. In this study, the influence of different site profiles on computed ground motion was investigated using a 2D equivalent linear analysis approach. Four distinct site profiles: sand, clay, sand-clay-sand-clay, and clay-sand-clay-sand profiles were considered. The results were presented using multiple metrics, including surface acceleration, displacement, modulus decreasing ratio, and coherence analysis. Notably, the clay profile significantly influenced ground motion, while the sand profile exhibited relatively lower seismic activity. This suggests that softer sites significantly influence ground motion, leading to potentially high levels of shaking.
{"title":"2D equivalent linear ground response analysis for randomized site profiles","authors":"A. Chala, Richard Ray","doi":"10.1556/606.2024.00995","DOIUrl":"https://doi.org/10.1556/606.2024.00995","url":null,"abstract":"Local soil conditions play a crucial role in shaping ground surface responses and impacting the intensity of ground shaking. In this study, the influence of different site profiles on computed ground motion was investigated using a 2D equivalent linear analysis approach. Four distinct site profiles: sand, clay, sand-clay-sand-clay, and clay-sand-clay-sand profiles were considered. The results were presented using multiple metrics, including surface acceleration, displacement, modulus decreasing ratio, and coherence analysis. Notably, the clay profile significantly influenced ground motion, while the sand profile exhibited relatively lower seismic activity. This suggests that softer sites significantly influence ground motion, leading to potentially high levels of shaking.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"20 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141020191","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}
Cylinder bore coatings are widely used in automotive internal combustion engines to replace cylinder liners. During the atmospheric plasma spraying process, the coatings are oxidized and controlled by the Si content of the steel powder used as the coating raw material. This phenomenon affects the technological process, the microstructure, and the properties of the formed coatings. The research aims to investigate how the Si content of two commercial grades of steel powder commonly used in industry affects the undesirable consequences observed in practice, such as clogging of powder nozzles or large variations in coating hardness. The analyses and industrial experiments show that increasing the Si content can contribute significantly to these undesirable phenomena.
汽缸孔涂层被广泛应用于汽车内燃机，以取代汽缸套。在大气等离子喷涂过程中，涂层会被氧化，并受涂层原料钢粉中 Si 含量的控制。这种现象会影响工艺流程、微观结构和所形成涂层的性能。本研究旨在探讨工业中常用的两种商用钢粉中的 Si 含量如何影响实践中观察到的不良后果，如粉末喷嘴堵塞或涂层硬度变化大。分析和工业实验表明，增加硅含量会大大加剧这些不良现象。
{"title":"Microstructural and profilometric analysis of thermally sprayed cylinder wall coatings","authors":"Akos Kokai, Maria Berkes Maros","doi":"10.1556/606.2024.01076","DOIUrl":"https://doi.org/10.1556/606.2024.01076","url":null,"abstract":"Cylinder bore coatings are widely used in automotive internal combustion engines to replace cylinder liners. During the atmospheric plasma spraying process, the coatings are oxidized and controlled by the Si content of the steel powder used as the coating raw material. This phenomenon affects the technological process, the microstructure, and the properties of the formed coatings. The research aims to investigate how the Si content of two commercial grades of steel powder commonly used in industry affects the undesirable consequences observed in practice, such as clogging of powder nozzles or large variations in coating hardness. The analyses and industrial experiments show that increasing the Si content can contribute significantly to these undesirable phenomena.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"93 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141019268","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}
This study evaluates metallic yield dampers, specifically slit steel dampers, for protecting steel beam-to-column connections during seismic events. Finite element model simulations were conducted for the damper and its connection. Analysis of circular parameters, like the radius slot, showed that appropriately sized slit dampers exhibit advantageous seismic behavior. Moment-rotation, hysteresis curves, and plastic stresses comparisons indicate efficient energy absorption. The maximum moment was 25% lower than conventional samples. The slit steel damper model with a ductility factor of 3.5 allows significant plastic deformation before potential failure. Results emphasize the slit damper's potential for optimal performance in steel frames, suggesting its use for efficient energy absorption.
{"title":"Seismic evaluation of steel beam-column connection equipped by circular slit dampers","authors":"Alaa T. Mohammed, H. Sultan","doi":"10.1556/606.2024.00996","DOIUrl":"https://doi.org/10.1556/606.2024.00996","url":null,"abstract":"This study evaluates metallic yield dampers, specifically slit steel dampers, for protecting steel beam-to-column connections during seismic events. Finite element model simulations were conducted for the damper and its connection. Analysis of circular parameters, like the radius slot, showed that appropriately sized slit dampers exhibit advantageous seismic behavior. Moment-rotation, hysteresis curves, and plastic stresses comparisons indicate efficient energy absorption. The maximum moment was 25% lower than conventional samples. The slit steel damper model with a ductility factor of 3.5 allows significant plastic deformation before potential failure. Results emphasize the slit damper's potential for optimal performance in steel frames, suggesting its use for efficient energy absorption.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"11 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140673877","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}
Mahmood Alhafadhi, Masar Alsigar, Oudah Zahraa A., Z. Bézi, Alden abd alal Sahm, P. R. Reddy
Using finite element methods, residual stresses were estimated in pipe welds. Experiments were also conducted to verify the numerical results. An alternative to a three-dimensional model was used to simplify the numerical calculation for residual stresses investigation. Model predictions were validated by measuring residual stresses using X-ray diffraction. As compared to measured residual stress distributions, the computational approaches developed in this study can accurately predict welding residual stress distributions. The focused welding parameters have a significant impact on residual stresses even when all the other parameters are the same.
使用有限元方法估算了管道焊缝中的残余应力。还进行了实验来验证数值结果。为了简化残余应力研究的数值计算，使用了三维模型的替代方法。通过使用 X 射线衍射测量残余应力，对模型预测进行了验证。与测量的残余应力分布相比，本研究开发的计算方法可以准确预测焊接残余应力分布。即使其他参数相同，重点焊接参数也会对残余应力产生重大影响。
{"title":"Influence of heat input and preheating on residual stresses in pipe weld","authors":"Mahmood Alhafadhi, Masar Alsigar, Oudah Zahraa A., Z. Bézi, Alden abd alal Sahm, P. R. Reddy","doi":"10.1556/606.2023.00589","DOIUrl":"https://doi.org/10.1556/606.2023.00589","url":null,"abstract":"Using finite element methods, residual stresses were estimated in pipe welds. Experiments were also conducted to verify the numerical results. An alternative to a three-dimensional model was used to simplify the numerical calculation for residual stresses investigation. Model predictions were validated by measuring residual stresses using X-ray diffraction. As compared to measured residual stress distributions, the computational approaches developed in this study can accurately predict welding residual stress distributions. The focused welding parameters have a significant impact on residual stresses even when all the other parameters are the same.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"46 41","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140701885","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}
O. Voznyak, Edyta Dudkiewicz, N. Spodyniuk, O. Dovbush, I. Sukholova, Olena Savchenko, M. Kasynets
The immediate vicinity of buildings of different floors causes damages of the smoke and ventilation channels work of the low-rise buildings. This is dangerous for the resident's health and lives. To determine the impact of high-rise buildings on the operation of air channels of a nearby two-story building, experimental research has been carried out in a wind tunnel. Charts and analytical formulas have been designed for determining the buildings aerodynamic coefficients depending on wind directions and the channels height. An increase of the channel height results in an increase in static rarefaction in smoke and ventilation channels. Increasing rarefaction increases the efficiency of the natural ventilation system and ensures the residents health and life.
{"title":"Aerodynamic parameters of buildings at different floors in the immediate vicinity","authors":"O. Voznyak, Edyta Dudkiewicz, N. Spodyniuk, O. Dovbush, I. Sukholova, Olena Savchenko, M. Kasynets","doi":"10.1556/606.2023.00950","DOIUrl":"https://doi.org/10.1556/606.2023.00950","url":null,"abstract":"The immediate vicinity of buildings of different floors causes damages of the smoke and ventilation channels work of the low-rise buildings. This is dangerous for the resident's health and lives. To determine the impact of high-rise buildings on the operation of air channels of a nearby two-story building, experimental research has been carried out in a wind tunnel. Charts and analytical formulas have been designed for determining the buildings aerodynamic coefficients depending on wind directions and the channels height. An increase of the channel height results in an increase in static rarefaction in smoke and ventilation channels. Increasing rarefaction increases the efficiency of the natural ventilation system and ensures the residents health and life.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"264 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140249401","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}
B. Udayasree, Avuthu Narender Reddy, Yadav Suvidha, Prathik Kulkarni, C. A. Kumar, Bodevenkata Kavyatheja
This study highlights the effectiveness of the response surface method in predicting the properties of hardened concrete containing spent foundry sand and manufactured-sand. In current research, different mix proportions are prepared with spent foundry sand and manufactured-sand as partial replacements for fine aggregate. The workability, strength, and durability studies are conducted on all concrete mixes. The test results confirm that the inclusion of 20% of spent foundry sand is optimum for enhancing the strength and durability. Also, the inclusion of 20% of spent foundry sand in manufactured-sand concrete also possesses optimum results in strength and durability. Further, the response surface method has been employed to develop a model for compressive strength prediction. The R-squared and residual sum of squares of error for the compressive strength model were 0.9863 and 2.345, which confirms the goodness of the fit.
本研究强调了响应面法在预测含有废铸造砂和人造砂的硬化混凝土性能方面的有效性。在当前的研究中，使用废铸造砂和人造砂作为细骨料的部分替代品，配制了不同的混合比例。对所有混凝土混合料进行了工作性、强度和耐久性研究。试验结果证实，掺入 20% 的废铸造砂最有利于提高强度和耐久性。此外，在人造砂混凝土中加入 20% 的废铸造砂也能达到最佳强度和耐久性效果。此外，还采用了响应面法来建立抗压强度预测模型。抗压强度模型的 R 方和残余误差平方和分别为 0.9863 和 2.345，证实了拟合的良好性。
{"title":"Strength prediction of modified self-compacting concrete using response surface method","authors":"B. Udayasree, Avuthu Narender Reddy, Yadav Suvidha, Prathik Kulkarni, C. A. Kumar, Bodevenkata Kavyatheja","doi":"10.1556/606.2023.00948","DOIUrl":"https://doi.org/10.1556/606.2023.00948","url":null,"abstract":"This study highlights the effectiveness of the response surface method in predicting the properties of hardened concrete containing spent foundry sand and manufactured-sand. In current research, different mix proportions are prepared with spent foundry sand and manufactured-sand as partial replacements for fine aggregate. The workability, strength, and durability studies are conducted on all concrete mixes. The test results confirm that the inclusion of 20% of spent foundry sand is optimum for enhancing the strength and durability. Also, the inclusion of 20% of spent foundry sand in manufactured-sand concrete also possesses optimum results in strength and durability. Further, the response surface method has been employed to develop a model for compressive strength prediction. The R-squared and residual sum of squares of error for the compressive strength model were 0.9863 and 2.345, which confirms the goodness of the fit.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"49 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140087470","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}
Local scour poses a grave threat to bridge foundations, potentially causing catastrophic collapses. This study uses FLOW-3D with the Reynolds-Averaged Navier-Stokes model to analyze pier scour and dune formation under bridges. It focuses on submerged debris shapes near the water's surface. Results closely match experiments when specific conditions are met. The study introduces an innovative approach to debris impact assessment. Instead of traditional methods, it proposes a novel equation accounting for debris's effective area and elevation. This enhances reliability by over 20%, improving scour depth assessment in debris-laden scenarios. This advances the understanding of debris's role in local scour, benefiting bridge design and management practices.
{"title":"Enhancing pier local scour prediction in the presence of floating debris","authors":"Muhanad Al-Jubouri, Richard P. Ray","doi":"10.1556/606.2023.00952","DOIUrl":"https://doi.org/10.1556/606.2023.00952","url":null,"abstract":"Local scour poses a grave threat to bridge foundations, potentially causing catastrophic collapses. This study uses FLOW-3D with the Reynolds-Averaged Navier-Stokes model to analyze pier scour and dune formation under bridges. It focuses on submerged debris shapes near the water's surface. Results closely match experiments when specific conditions are met. The study introduces an innovative approach to debris impact assessment. Instead of traditional methods, it proposes a novel equation accounting for debris's effective area and elevation. This enhances reliability by over 20%, improving scour depth assessment in debris-laden scenarios. This advances the understanding of debris's role in local scour, benefiting bridge design and management practices.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"204 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140448732","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}
Present paper shows the different types of tensor product model based linear matrix inequality controller design and feasibility analysis of two degrees of freedom aeroelastic wing section model. The tensor product models are based on reducing or removing the nonlinear behavior of the system and weighting functions. The linear matrix inequality based method results globally asymptotically stable system. The goal of the paper is to examine that selecting and varying the transformation space influences the feasibility of the linear matrix inequality based controller. The paper gives a comparison between the different tensor product models in terms of controller performance. The linear matrix inequality gives feasible solution for the controller design if the transformation space is selected adequately.
{"title":"LMI feasibility analysis of 2DOF NATA model","authors":"A. Wéber, M. Kuczmann","doi":"10.1556/606.2024.00888","DOIUrl":"https://doi.org/10.1556/606.2024.00888","url":null,"abstract":"Present paper shows the different types of tensor product model based linear matrix inequality controller design and feasibility analysis of two degrees of freedom aeroelastic wing section model. The tensor product models are based on reducing or removing the nonlinear behavior of the system and weighting functions. The linear matrix inequality based method results globally asymptotically stable system. The goal of the paper is to examine that selecting and varying the transformation space influences the feasibility of the linear matrix inequality based controller. The paper gives a comparison between the different tensor product models in terms of controller performance. The linear matrix inequality gives feasible solution for the controller design if the transformation space is selected adequately.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"17 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140450752","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}
This study evaluated the thermal performance of side divergence and uniform micro-channel heat sinks by comparing and contrasting them. Heat transfer and fluid flow characteristics in these micro-channel configurations were studied using computational fluid dynamics simulations employing ANSYS Fluent 2017 code for this purpose. Laminar flow through micro-channels with a Reynolds number of 207 was the subject of the investigation. The goal is to determine how side divergence affects heat dissipation efficiency concerning traditional uniform micro-channels. The results showed that the best divergence ratio is 1.5 that achieved the highest performance. The study also revealed that side divergence micro-channel heat sinks can achieve thermal performance up to 14% higher than uniform micro-channel heat sinks.
{"title":"Comparative analysis of microchannel heat sinks for thermal performance enhancement","authors":"Dhay Abd Al Hasan Jawad, S. Ahmed","doi":"10.1556/606.2023.00989","DOIUrl":"https://doi.org/10.1556/606.2023.00989","url":null,"abstract":"This study evaluated the thermal performance of side divergence and uniform micro-channel heat sinks by comparing and contrasting them. Heat transfer and fluid flow characteristics in these micro-channel configurations were studied using computational fluid dynamics simulations employing ANSYS Fluent 2017 code for this purpose. Laminar flow through micro-channels with a Reynolds number of 207 was the subject of the investigation. The goal is to determine how side divergence affects heat dissipation efficiency concerning traditional uniform micro-channels. The results showed that the best divergence ratio is 1.5 that achieved the highest performance. The study also revealed that side divergence micro-channel heat sinks can achieve thermal performance up to 14% higher than uniform micro-channel heat sinks.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"43 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139838455","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}
Maher F. Al Lebban, Ameer A. Alraie, Q. A. Jabal, Laith Abdul Rasool Alasadi, Rawa Shakir Muwashee, W. H. Mahdi
Progress in building construction requires more durable concrete with higher strength. Polymer and water reducer liquids can improve concrete strength and durability. This research aims to improve the mechanical properties of polymer-modified concrete by using anti-slip sand and silica fume to achieve more durable concrete against sulfate attack and higher mechanical properties. The study shows an increase in compressive strength from 25.7 MPa for reference mix to 45.5 MPa using 15% silica fume and 30% Anti-slip sand; tensile strength increased from 2.72 to 4.4 MPa. Flexural strength also increased, and durability to sulfate attack also increased. The study includes the increment of durability against freezing-thawing cycles for different mixes.
{"title":"The effect of anti-slip aggregate and silica fume on polymer-modified concrete","authors":"Maher F. Al Lebban, Ameer A. Alraie, Q. A. Jabal, Laith Abdul Rasool Alasadi, Rawa Shakir Muwashee, W. H. Mahdi","doi":"10.1556/606.2023.00958","DOIUrl":"https://doi.org/10.1556/606.2023.00958","url":null,"abstract":"Progress in building construction requires more durable concrete with higher strength. Polymer and water reducer liquids can improve concrete strength and durability. This research aims to improve the mechanical properties of polymer-modified concrete by using anti-slip sand and silica fume to achieve more durable concrete against sulfate attack and higher mechanical properties. The study shows an increase in compressive strength from 25.7 MPa for reference mix to 45.5 MPa using 15% silica fume and 30% Anti-slip sand; tensile strength increased from 2.72 to 4.4 MPa. Flexural strength also increased, and durability to sulfate attack also increased. The study includes the increment of durability against freezing-thawing cycles for different mixes.","PeriodicalId":35003,"journal":{"name":"Pollack Periodica","volume":"66 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139779126","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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