Electricity produced in power plants is essential in our everyday life. In general, the energy transfer takes place after processing the energy source in boilers or steam generators. Steam is generated through this process, that operates the turbines and they generate electricity through the generators. As such equipment operates in a high pressure, corrosive and high temperature environment, these circumstances may damage the tubes in the heat exchangers. Our research examines the potential of corrosion of heat exchanger tubes after welding. The typical corrosion process is pitting. The corrosion resistance of stainless steel depends on a protective, passive film formed on the surface of the steel exposed to the service environment. The use of fusion welding for fabrication leads to local variations in the chemical composition inside the material, which may significantly alter the stability of the passive layer and hence the corrosion behavior. The impact of welding parameters (shielding gas, amperage) was examined on corrosion resistance of X6CrNiTi18-10 austenitic stainless steel. The corrosion test was performed according to ASTM G48 standard. The weight loss was measured in Fe(III)-chloride solution by the first corrosion test. The results showed that the corrosion resistance of stainless steel was better at 50 A and 10 l/min welding parameters. During the second test, a potentiodynamic corrosion test was made, and the potentiodynamic curve was measured in 9% saline solution. In this solution, the stainless steel had a better corrosion property because it was measured in a less aggressive medium.
{"title":"The Effect of Welding Parameters on the Corrosion Resistance of Austenitic Stainless Steel","authors":"D. Kemény, D. Kovács","doi":"10.3311/ppme.19568","DOIUrl":"https://doi.org/10.3311/ppme.19568","url":null,"abstract":"Electricity produced in power plants is essential in our everyday life. In general, the energy transfer takes place after processing the energy source in boilers or steam generators. Steam is generated through this process, that operates the turbines and they generate electricity through the generators. As such equipment operates in a high pressure, corrosive and high temperature environment, these circumstances may damage the tubes in the heat exchangers. Our research examines the potential of corrosion of heat exchanger tubes after welding. The typical corrosion process is pitting. The corrosion resistance of stainless steel depends on a protective, passive film formed on the surface of the steel exposed to the service environment. The use of fusion welding for fabrication leads to local variations in the chemical composition inside the material, which may significantly alter the stability of the passive layer and hence the corrosion behavior. The impact of welding parameters (shielding gas, amperage) was examined on corrosion resistance of X6CrNiTi18-10 austenitic stainless steel. The corrosion test was performed according to ASTM G48 standard. The weight loss was measured in Fe(III)-chloride solution by the first corrosion test. The results showed that the corrosion resistance of stainless steel was better at 50 A and 10 l/min welding parameters. During the second test, a potentiodynamic corrosion test was made, and the potentiodynamic curve was measured in 9% saline solution. In this solution, the stainless steel had a better corrosion property because it was measured in a less aggressive medium.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90695102","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}
A great deal of investigation on gas tungsten arc cladding (GTAC) is focused on the study of enhancements in the microstructure, mechanical and tribological features of the cladding. The selection of right process parameters is a critical issue for the researchers. Decision makers in the industries must analyze a wide variety of parameters based on a set of contradictory criteria. Several multi-criteria decision-making (MCDM) techniques are now available to add values in selection of these parameters. The application of the TOPSIS and MOORA techniques to identify the best configuration of processing parameters in the gas tungsten arc cladding (GTAC) process is investigated in this work. The best processing parameters set for the multiple performance attributes should be welding current: 70 amp, speed: 240, argon flow: 13 and standoff distance 3.5 (TOPSIS-PCA) and welding current: 50, speed: 300, argon flow: 13 and standoff distance 3.5 (MOORA-PCA).A comparison of MOORA-PCA and TOPSIS-PCA demonstrates the superiority of TOPSIS over MOORA technique. The prediction accuracy of the TOPSIS-PCA hybrid approach model is found better than MOORA-PCA technique.
{"title":"Comparison of Multi-Criteria Decision Making Methods for Multi Optimization of GTAC Process Parameters","authors":"R. Ranjan, A. Saha, Anil Kumar Das Kumar Das","doi":"10.3311/ppme.19835","DOIUrl":"https://doi.org/10.3311/ppme.19835","url":null,"abstract":"A great deal of investigation on gas tungsten arc cladding (GTAC) is focused on the study of enhancements in the microstructure, mechanical and tribological features of the cladding. The selection of right process parameters is a critical issue for the researchers. Decision makers in the industries must analyze a wide variety of parameters based on a set of contradictory criteria. Several multi-criteria decision-making (MCDM) techniques are now available to add values in selection of these parameters. The application of the TOPSIS and MOORA techniques to identify the best configuration of processing parameters in the gas tungsten arc cladding (GTAC) process is investigated in this work. The best processing parameters set for the multiple performance attributes should be welding current: 70 amp, speed: 240, argon flow: 13 and standoff distance 3.5 (TOPSIS-PCA) and welding current: 50, speed: 300, argon flow: 13 and standoff distance 3.5 (MOORA-PCA).A comparison of MOORA-PCA and TOPSIS-PCA demonstrates the superiority of TOPSIS over MOORA technique. The prediction accuracy of the TOPSIS-PCA hybrid approach model is found better than MOORA-PCA technique.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87850059","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}
In this paper results of chromatic discrimination measurements obtained in two lighting scenarios are compared. Chromatic discrimination thresholds were measured in relation with systematically manipulated chromaticities seen under different visual angles. In both cases the Ellipse module of the Cambridge Colour Test (CCT) was obtained binocularly by normal colour-observers. Discrimination ellipses fitted to the measured thresholds were compared in terms of the adapting chromaticity and the visual angle of the adapting stimulus. Our findings show that changes in the reference chromaticity of the CCT have stronger effect on the elongation of the chromatic discrimination ellipses compared to the effect of the adapting chromaticity obtained in a light booth.Further comparison of discrimination thresholds estimated towards the confusion directions and the corresponding radii of the Ellipse test results suggests that the reliability of the Ellipse test results depends on the relation between the measurement directions and the confusion directions.
{"title":"The Effect of the Field of Adaptation on Chromatic Discrimination Ellipses","authors":"Á. Urbin, B. Nagy, K. Wenzel","doi":"10.3311/ppme.19552","DOIUrl":"https://doi.org/10.3311/ppme.19552","url":null,"abstract":"In this paper results of chromatic discrimination measurements obtained in two lighting scenarios are compared. Chromatic discrimination thresholds were measured in relation with systematically manipulated chromaticities seen under different visual angles. In both cases the Ellipse module of the Cambridge Colour Test (CCT) was obtained binocularly by normal colour-observers. Discrimination ellipses fitted to the measured thresholds were compared in terms of the adapting chromaticity and the visual angle of the adapting stimulus. Our findings show that changes in the reference chromaticity of the CCT have stronger effect on the elongation of the chromatic discrimination ellipses compared to the effect of the adapting chromaticity obtained in a light booth.Further comparison of discrimination thresholds estimated towards the confusion directions and the corresponding radii of the Ellipse test results suggests that the reliability of the Ellipse test results depends on the relation between the measurement directions and the confusion directions.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79525675","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}
M. Stojkov, Krešimir Crnogorac, Tomislav Alinjak, Bernarda Crnogorac
This paper presents research of energy performance analysis performed by Building Energy Management System (BEMS). BEMS is a system/platform integrated with building and it is an enormous improvement in a process to develop nearly zero energy buildings (nZEB). Near zero energy consumption stands for energy efficient idea of energy independent buildings for their function during their life time. Here, BEMS with function of monitoring and regulation of cooling energy demand is developed. BEMS regulates function of ventilation fan in area below tin roof and improves working conditions by inside building temperature reduction during summer period. Described technical solution is designed inside RESCUE IPA CBC project.
{"title":"Monitoring and Regulation of Indoor Conditions","authors":"M. Stojkov, Krešimir Crnogorac, Tomislav Alinjak, Bernarda Crnogorac","doi":"10.3311/ppme.19443","DOIUrl":"https://doi.org/10.3311/ppme.19443","url":null,"abstract":"This paper presents research of energy performance analysis performed by Building Energy Management System (BEMS). BEMS is a system/platform integrated with building and it is an enormous improvement in a process to develop nearly zero energy buildings (nZEB). Near zero energy consumption stands for energy efficient idea of energy independent buildings for their function during their life time. Here, BEMS with function of monitoring and regulation of cooling energy demand is developed. BEMS regulates function of ventilation fan in area below tin roof and improves working conditions by inside building temperature reduction during summer period. Described technical solution is designed inside RESCUE IPA CBC project.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81183730","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}
The behaviour of fibre-reinforced composites greatly depends on their layup structures. Through a full-field layup optimization study based on multiple parameters, this paper investigates how different properties change with the layup. The aim was to maximize the extension-twist coupling performance while ensuring adequate bending stiffness and low thermal warpage to make the laminate suitable for shape-adaptive helicopter rotor blade application. The Classical Laminate Theory-based calculations revealed that satisfying the bending compliance and thermal warpage criteria significantly limited the achievable extension-twist performance. The warpage limit affected the desired coupling behaviour more because both properties are driven by terms in the extensional-bending compliance matrix, unlike bending compliance. Symmetric laminates do not have an intrinsic extension-twist capability, but some asymmetric laminates demonstrated significant coupling performance while being practically warpage-free (based on the ISO2768 standard). The results prove that the advantages of asymmetric laminates can outweigh their sometimes negligible disadvantages. The paper also investigates if there is a universal tendency in how layup homogenization affects the terms of the bending compliance matrix of composites. Through analytical calculations, we showed that depending on the layup of the sub-laminate, homogenization can increase or reduce the value of any term in the bending compliance matrix; therefore, there is no universal tendency. Based on these results, layup homogenization cannot only be exploited for its most general purpose – warpage mitigation – but also for improving other characteristics of the laminate (e.g. reducing the bending compliance for increased bending stiffness or increasing the bend-twist compliance for improved coupling performance).
{"title":"Multi-Parameter Layup Optimization and the Effect of Layup Homogenization on the Bending Compliance Matrix of Coupled Composites","authors":"T. Czigány, Brúnó Vermes","doi":"10.3311/ppme.19702","DOIUrl":"https://doi.org/10.3311/ppme.19702","url":null,"abstract":"The behaviour of fibre-reinforced composites greatly depends on their layup structures. Through a full-field layup optimization study based on multiple parameters, this paper investigates how different properties change with the layup. The aim was to maximize the extension-twist coupling performance while ensuring adequate bending stiffness and low thermal warpage to make the laminate suitable for shape-adaptive helicopter rotor blade application. The Classical Laminate Theory-based calculations revealed that satisfying the bending compliance and thermal warpage criteria significantly limited the achievable extension-twist performance. The warpage limit affected the desired coupling behaviour more because both properties are driven by terms in the extensional-bending compliance matrix, unlike bending compliance. Symmetric laminates do not have an intrinsic extension-twist capability, but some asymmetric laminates demonstrated significant coupling performance while being practically warpage-free (based on the ISO2768 standard). The results prove that the advantages of asymmetric laminates can outweigh their sometimes negligible disadvantages. The paper also investigates if there is a universal tendency in how layup homogenization affects the terms of the bending compliance matrix of composites. Through analytical calculations, we showed that depending on the layup of the sub-laminate, homogenization can increase or reduce the value of any term in the bending compliance matrix; therefore, there is no universal tendency. Based on these results, layup homogenization cannot only be exploited for its most general purpose – warpage mitigation – but also for improving other characteristics of the laminate (e.g. reducing the bending compliance for increased bending stiffness or increasing the bend-twist compliance for improved coupling performance).","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87781297","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}
Benhanifia Kada, Rahmani Lakhdar, Mebarki Brahim, H. Ameur
The fluid flows and power consumption in a vessel stirred by anchor impellers are investigated in this paper. The case of rheologically complex fluids modeled by the Bingham-Papanastasiou model is considered. New modifications in the design of the classical anchor impeller are introduced. A horizontal blade is added to the standard geometry of the anchor, and the effect of its inclination angle (α) is explored. Four geometrical configurations are realized, namely: α = 0°, 20°, 40°, and 60°. The effects of the number of added horizontal blades, Reynolds number, and Bingham number are also examined. The obtained findings reveal that the most efficient impeller design is that with (case 4) arm blades inclined by 60°.This case allowed the most expansive cavern size with enhanced shearing in the whole vessel volume. The effect of adding second horizontal arm blades (with 60°) gave better hydrodynamic performance only with a slight increase in power consumption. A significant impact of Bingham number (Bn) was observed, where Bn = 5 allowed obtaining the lowest power input and most expansive well-stirred region.
{"title":"Agitation of Complex Fluids in Cylindrical Vessels by Newly Designed Anchor Impellers","authors":"Benhanifia Kada, Rahmani Lakhdar, Mebarki Brahim, H. Ameur","doi":"10.3311/ppme.18438","DOIUrl":"https://doi.org/10.3311/ppme.18438","url":null,"abstract":"The fluid flows and power consumption in a vessel stirred by anchor impellers are investigated in this paper. The case of rheologically complex fluids modeled by the Bingham-Papanastasiou model is considered. New modifications in the design of the classical anchor impeller are introduced. A horizontal blade is added to the standard geometry of the anchor, and the effect of its inclination angle (α) is explored. Four geometrical configurations are realized, namely: α = 0°, 20°, 40°, and 60°. The effects of the number of added horizontal blades, Reynolds number, and Bingham number are also examined. The obtained findings reveal that the most efficient impeller design is that with (case 4) arm blades inclined by 60°.This case allowed the most expansive cavern size with enhanced shearing in the whole vessel volume. The effect of adding second horizontal arm blades (with 60°) gave better hydrodynamic performance only with a slight increase in power consumption. A significant impact of Bingham number (Bn) was observed, where Bn = 5 allowed obtaining the lowest power input and most expansive well-stirred region.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87099051","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}
Welding is accompanied by the presence of weld residual stresses, which in case of dissimilar metal welds even with post weld heat treatment cannot be removed completely therefore they should be considered when assessing possible welding defects. The measurement of residual stress in metal weld is a very complex procedure and also in the investigated case could not be carried out as it is the part of a working plant. However, by modelling these processes, the residual stresses and deformation of the components caused by this manufacturing method can be determined. It is important to calculate these values as accurately as possible to determine the maximum load capacity of the structure. The structure under examination was the dissimilar metal weld of a VVER-440 steam generator. 2D simulations were performed, where temperature and phase-dependent material properties were implemented. Different loading scenarios were considered in the numerical analysis. The results can be useful to determine the real loading conditions of a given component and can be used to predict stress corrosion crack initiation locations, as well as to evaluate the lifetime and failure mode prediction of welded joints.
{"title":"Study of the Stress State of a Dissimilar Metal Weld Due to Manufacturing and Operational Conditions","authors":"Bernadett Spisák, Z. Bézi, S. Szávai","doi":"10.3311/ppme.19063","DOIUrl":"https://doi.org/10.3311/ppme.19063","url":null,"abstract":"Welding is accompanied by the presence of weld residual stresses, which in case of dissimilar metal welds even with post weld heat treatment cannot be removed completely therefore they should be considered when assessing possible welding defects. The measurement of residual stress in metal weld is a very complex procedure and also in the investigated case could not be carried out as it is the part of a working plant. However, by modelling these processes, the residual stresses and deformation of the components caused by this manufacturing method can be determined. It is important to calculate these values as accurately as possible to determine the maximum load capacity of the structure. The structure under examination was the dissimilar metal weld of a VVER-440 steam generator. 2D simulations were performed, where temperature and phase-dependent material properties were implemented. Different loading scenarios were considered in the numerical analysis. The results can be useful to determine the real loading conditions of a given component and can be used to predict stress corrosion crack initiation locations, as well as to evaluate the lifetime and failure mode prediction of welded joints.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76548003","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}
If the draught and the radiant thermal asymmetry caused by the warm ceiling appear simultaneously, will women and men be affected in the same way? This research aims to answer this question, by clarifying the understanding of the joint mechanism of action of the two local discomfort factors with the help of instrumental and human subject measurements. The most important result of the present research is identifying that if PPD < 6%, radiant thermal asymmetry varies in the range of 5–15 °C and the draught rate DR = 15% or DR = 25%, then at a given range of the interval men are significantly more dissatisfied with warm ceilings than women; women’s AMV votes are significantly lower than men's; In the case of DR = 15%, the work accuracy of women is significantly higher, while in the case of men, the work accuracy is higher at DR = 25%.
{"title":"The Effect of Genders on the Perception of the Combined Effect of Local Discomfort Parameters","authors":"Balázs András-Tövissi, L. Kajtár","doi":"10.3311/ppme.18249","DOIUrl":"https://doi.org/10.3311/ppme.18249","url":null,"abstract":"If the draught and the radiant thermal asymmetry caused by the warm ceiling appear simultaneously, will women and men be affected in the same way? This research aims to answer this question, by clarifying the understanding of the joint mechanism of action of the two local discomfort factors with the help of instrumental and human subject measurements. The most important result of the present research is identifying that if PPD < 6%, radiant thermal asymmetry varies in the range of 5–15 °C and the draught rate DR = 15% or DR = 25%, then at a given range of the interval men are significantly more dissatisfied with warm ceilings than women; women’s AMV votes are significantly lower than men's; In the case of DR = 15%, the work accuracy of women is significantly higher, while in the case of men, the work accuracy is higher at DR = 25%.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89743804","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 paper aims to present that the effect of sampling can result in multi-frequency vibration even in the case of a single-degree-of-freedom linear mechanical model. Even though the sampled-data systems have an infinite number of characteristic exponents due to sampling, the vibrations of these systems can still be characterized by an effective system model with a single dominant frequency. However, as this paper shows, additional harmonics become relevant, resulting in multi-frequency vibrations depending on the magnitude of applied control parameters. The vibrations presented by the time histories of vibration and their spectra resulted in numerical simulation of the sampled-data system.
{"title":"Vibrations in Single-Degrees-of-Freedom Sampled-Data Linear Mechanical Systems","authors":"Csaba Budai","doi":"10.3311/ppme.19150","DOIUrl":"https://doi.org/10.3311/ppme.19150","url":null,"abstract":"This paper aims to present that the effect of sampling can result in multi-frequency vibration even in the case of a single-degree-of-freedom linear mechanical model. Even though the sampled-data systems have an infinite number of characteristic exponents due to sampling, the vibrations of these systems can still be characterized by an effective system model with a single dominant frequency. However, as this paper shows, additional harmonics become relevant, resulting in multi-frequency vibrations depending on the magnitude of applied control parameters. The vibrations presented by the time histories of vibration and their spectra resulted in numerical simulation of the sampled-data system.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81169163","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}
The tensile strength of newly developed ultra-high strength steel grades is now above 1800 MPa, and even new steel grades are currently in development. One typical welding process to join thin steels sheets is resistance spot welding (RSW). Some standardized and not standardized formulas predict the minimal shear tension strength (STS) of RSWed joints, but those formulas are less and less accurate with the higher base materials strength. Therefore, in our current research, we investigated a significant amount of STS data of the professional literature and our own experiments and recommended a new formula to predict the STS of RSWed high strength steel joints. The proposed correlation gives a better prediction than the other formulas, not only in the ultra-high strength steel range but also in the lower steel strength domain.
{"title":"Prediction of the Shear Tension Strength of Resistance Spot Welded Thin Steel Sheets from High- to Ultrahigh Strength Range","authors":"K. Májlinger, L. Katula, B. Varbai","doi":"10.3311/ppme.18934","DOIUrl":"https://doi.org/10.3311/ppme.18934","url":null,"abstract":"The tensile strength of newly developed ultra-high strength steel grades is now above 1800 MPa, and even new steel grades are currently in development. One typical welding process to join thin steels sheets is resistance spot welding (RSW). Some standardized and not standardized formulas predict the minimal shear tension strength (STS) of RSWed joints, but those formulas are less and less accurate with the higher base materials strength. Therefore, in our current research, we investigated a significant amount of STS data of the professional literature and our own experiments and recommended a new formula to predict the STS of RSWed high strength steel joints. The proposed correlation gives a better prediction than the other formulas, not only in the ultra-high strength steel range but also in the lower steel strength domain.","PeriodicalId":43630,"journal":{"name":"PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80596032","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}