Pub Date : 2024-05-17DOI: 10.11648/j.ijmea.20241202.12
Nguyen Hinh, Ta Phong, Nguyen Hai
In this study, investigating the effect of different sizes, cut out shapes and different shapes of the structural to the ultimate strength of steel panels. The nonlinear finite element method is applied in this study. A series of simulations have been performed for the unstiffened panels have the cutouts with different shapes and sizes. Effect of size and cutout shapes to the ultimate strength of steel plates and different shapes of the structural. The relationship between stress and strain is investigated and analyzed. A relationship showed that the effects of different shapes of structural to ultimate strength is presented. The aim of this study is to evaluate the stress and ultimate strength of perforated structures with holes under the compression edge load. Which is the main action type arising from cargo weight and water pressure affecting the ships structure and offshore structures. The cutout is circular and elongated circular in the located in the center of the plate. A series of Abaqus nonlinear finite element analyses performed with cutout size is investigated. By regression analysis of the FEA results is obtained, it helps marine designers to give the optimum structure for simultaneous durability to ensure the maximum saving of raw materials.
{"title":"A Novel Evaluate the Ultimate Strength of Plate Having Cutout Under In-Plane Compression","authors":"Nguyen Hinh, Ta Phong, Nguyen Hai","doi":"10.11648/j.ijmea.20241202.12","DOIUrl":"https://doi.org/10.11648/j.ijmea.20241202.12","url":null,"abstract":"In this study, investigating the effect of different sizes, cut out shapes and different shapes of the structural to the ultimate strength of steel panels. The nonlinear finite element method is applied in this study. A series of simulations have been performed for the unstiffened panels have the cutouts with different shapes and sizes. Effect of size and cutout shapes to the ultimate strength of steel plates and different shapes of the structural. The relationship between stress and strain is investigated and analyzed. A relationship showed that the effects of different shapes of structural to ultimate strength is presented. The aim of this study is to evaluate the stress and ultimate strength of perforated structures with holes under the compression edge load. Which is the main action type arising from cargo weight and water pressure affecting the ships structure and offshore structures. The cutout is circular and elongated circular in the located in the center of the plate. A series of Abaqus nonlinear finite element analyses performed with cutout size is investigated. By regression analysis of the FEA results is obtained, it helps marine designers to give the optimum structure for simultaneous durability to ensure the maximum saving of raw materials.\u0000","PeriodicalId":471114,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"119 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141126401","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 : 2024-02-28DOI: 10.11648/j.ijmea.20241201.14
Tursunbaev Bakhodir, Fayzullaev Khasan, Tursunbaev Temur
This article presents the results of a study of internal combustion engines equipped with a crank mechanism according to the efficiency criterion using a new method for determining the operating efficiency of machines and engines. The study revealed the presence of parasitic forces in internal combustion engines equipped with a crank mechanism. The occurrence of parasitic forces present in internal combustion engines and the law of their dependence on the movement of the piston have been studied. As well as the negative impact of parasitic forces on engine efficiency. This article presents the main results of the study. As a result of the research, it was revealed that when converting the thermal energy generated in the combustion chamber of internal combustion engines equipped with a crank mechanism into mechanical work, more than 30% of the energy of the pressure force is spent on parasitic forces. The influence of the mechanical friction force (friction of the plain bearings) with the crankshaft on the effective torque was also studied. Thus, the inefficiency of internal combustion engines equipped with a crank mechanism has been theoretically and practically proven. Finally, recommendations are given for eliminating parasitic forces when designing new internal combustion engines. It is proposed to equip new internal combustion engines with mechanisms without parasitic forces. Equipping internal combustion engines with a mechanism that does not contain parasitic forces (that is, equipping them with more efficient mechanisms) significantly increases the possibility of efficient use of the thermal energy of the fuel introduced into the combustion chamber in internal combustion engines. Consequently, this increases the engine efficiency by 130%. or more. For internal combustion engines, a new mechanism is recommended that eliminates the loss of force and allows the use of rolling bearings. This feature of the new mechanism makes it possible to increase the efficiency of internal combustion engines by another 4-6%. From previous studies it is known that the efficiency of a rolling bearing relative to a plain bearing is more than 2-3 times.
{"title":"Checking the Mechanisms of Internal Combustion Engines for the Presence of Parasitic Forces Using a New Methodology","authors":"Tursunbaev Bakhodir, Fayzullaev Khasan, Tursunbaev Temur","doi":"10.11648/j.ijmea.20241201.14","DOIUrl":"https://doi.org/10.11648/j.ijmea.20241201.14","url":null,"abstract":"This article presents the results of a study of internal combustion engines equipped with a crank mechanism according to the efficiency criterion using a new method for determining the operating efficiency of machines and engines. The study revealed the presence of parasitic forces in internal combustion engines equipped with a crank mechanism. The occurrence of parasitic forces present in internal combustion engines and the law of their dependence on the movement of the piston have been studied. As well as the negative impact of parasitic forces on engine efficiency. This article presents the main results of the study. As a result of the research, it was revealed that when converting the thermal energy generated in the combustion chamber of internal combustion engines equipped with a crank mechanism into mechanical work, more than 30% of the energy of the pressure force is spent on parasitic forces. The influence of the mechanical friction force (friction of the plain bearings) with the crankshaft on the effective torque was also studied. Thus, the inefficiency of internal combustion engines equipped with a crank mechanism has been theoretically and practically proven. Finally, recommendations are given for eliminating parasitic forces when designing new internal combustion engines. It is proposed to equip new internal combustion engines with mechanisms without parasitic forces. Equipping internal combustion engines with a mechanism that does not contain parasitic forces (that is, equipping them with more efficient mechanisms) significantly increases the possibility of efficient use of the thermal energy of the fuel introduced into the combustion chamber in internal combustion engines. Consequently, this increases the engine efficiency by 130%. or more. For internal combustion engines, a new mechanism is recommended that eliminates the loss of force and allows the use of rolling bearings. This feature of the new mechanism makes it possible to increase the efficiency of internal combustion engines by another 4-6%. From previous studies it is known that the efficiency of a rolling bearing relative to a plain bearing is more than 2-3 times.","PeriodicalId":471114,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"115 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140422578","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 : 2024-02-21DOI: 10.11648/j.ijmea.20241201.13
Sumanta Basu, Sushil Cherian, Jisna Johnson
Flexible operation of coal-fired power plants is becoming increasingly necessary for successful integration of large-scale renewable power generation into the power grid. The maximum ramp rate and the number of load cycles are generally limited by the thermal stress experienced by the boiler pressure parts, turbine metallurgy and creep and fatigue of critical thick-walled components Main steam temperature is a critical operating parameter that must be controlled within acceptable limits for safe operation. Main steam temperature deviation beyond acceptable limit has impact on boiler pressure parts and turbine material of construction due to creep and fatigue effect. Base load operating units do not require steep ramp rate and hence recommended ramping rates are kept low within the safe operating zone in comparison to the flexible operation of the units with wide range load change width. Thermal stresses are caused by the temperature changes inside the thick-walled components and turbine steam admission parameters. Hence, the quality of main steam temperature control plays a vital role in flexible operation of the coal fired units. Conventional cascaded PID temperature control loop architecture performs well at steady state condition within a limited variation of load change at low ramp rate but it acts slowly and performs poorly at transient operating conditions of flexible operation of the boiler turbine with wide range load variation and load cycle with high ramp rate and remains far from rated conditions. In this paper, a Multi-Input Multi-Output (MIMO) Non-linear Model Predictive Control (MPC) design for regulation of the main steam temperature of a Once-Through supercritical Boiler is proposed. The controller is based on a non-linear dynamic model which incorporates dynamics of the variables of interest. It has the capability to operate effectively across a wide load range while maintaining main steam temperature within acceptable limits. A notable advancement in this design of MPC is the incorporation of coal flow demand and feedwater flow demand as additional control inputs alongside primary and secondary spray flows. In simulation test cases, the MPC controller demonstrates satisfactory performance and computational efficiency.
{"title":"Design of Multi-Input Multi-Output Non-linear Model Predictive Control for Main Steam Temperature of Super Critical Boiler","authors":"Sumanta Basu, Sushil Cherian, Jisna Johnson","doi":"10.11648/j.ijmea.20241201.13","DOIUrl":"https://doi.org/10.11648/j.ijmea.20241201.13","url":null,"abstract":"Flexible operation of coal-fired power plants is becoming increasingly necessary for successful integration of large-scale renewable power generation into the power grid. The maximum ramp rate and the number of load cycles are generally limited by the thermal stress experienced by the boiler pressure parts, turbine metallurgy and creep and fatigue of critical thick-walled components Main steam temperature is a critical operating parameter that must be controlled within acceptable limits for safe operation. Main steam temperature deviation beyond acceptable limit has impact on boiler pressure parts and turbine material of construction due to creep and fatigue effect. Base load operating units do not require steep ramp rate and hence recommended ramping rates are kept low within the safe operating zone in comparison to the flexible operation of the units with wide range load change width. Thermal stresses are caused by the temperature changes inside the thick-walled components and turbine steam admission parameters. Hence, the quality of main steam temperature control plays a vital role in flexible operation of the coal fired units. Conventional cascaded PID temperature control loop architecture performs well at steady state condition within a limited variation of load change at low ramp rate but it acts slowly and performs poorly at transient operating conditions of flexible operation of the boiler turbine with wide range load variation and load cycle with high ramp rate and remains far from rated conditions. In this paper, a Multi-Input Multi-Output (MIMO) Non-linear Model Predictive Control (MPC) design for regulation of the main steam temperature of a Once-Through supercritical Boiler is proposed. The controller is based on a non-linear dynamic model which incorporates dynamics of the variables of interest. It has the capability to operate effectively across a wide load range while maintaining main steam temperature within acceptable limits. A notable advancement in this design of MPC is the incorporation of coal flow demand and feedwater flow demand as additional control inputs alongside primary and secondary spray flows. In simulation test cases, the MPC controller demonstrates satisfactory performance and computational efficiency.","PeriodicalId":471114,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"10 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140445282","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 : 2024-01-08DOI: 10.11648/j.ijmea.20241201.11
Muhammad Mubashar Saeed
{"title":"Investigation of the Surface Produced by Shape Adaptive Polishing","authors":"Muhammad Mubashar Saeed","doi":"10.11648/j.ijmea.20241201.11","DOIUrl":"https://doi.org/10.11648/j.ijmea.20241201.11","url":null,"abstract":"","PeriodicalId":471114,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"217 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139628681","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}
Additive manufacturing (AM) comes under the category of advanced manufacturing techniques that enables the manufacture of complex shaped components with reduction in multi-part assemblies, production lead times and weight. Maraging steel is a strategic material for manufacturing of components such as rocket motor casings, bulkheads etc. in defence and aerospace sectors. Laser Powder Bed Fusion (LPBF) AM technique has been explored in fabrication of Maraging steel components for end-use applications. In many applications, additively manufactured maraging steel parts are required to be welded to conventional material and it is important to understand weldability of these materials and their characteristics to ensure good bonding between the parts. It is also necessary to assess how welding process may affect the microstructure and consequently the mechanical properties of the AM maraging steel. In the present study, welding of AM maraging steel AM300 with conventional MDN250 was explored. With the available optimized parameters, maraging steel plates (160x100x6mm3) were additively manufactured at low porosity without any defects of soot and spatter. The effect of heat treatment conditions on the volume fraction of reverted austenite in AM300 was also studied to arrive at an appropriate condition before carrying out the welding of AM300 plates. XRD and EBSD analysis revealed the formation of very fine reverted austenite in the as-deposited (AD) and Direct-aged (DA) conditions at the cell boundaries. Specimens when subjected to solution-treated and aged (STA) condition had almost eliminated the formation of reverted austenite at room temperature. Thus, the AM processed plates were subjected to solution treatment before carrying out the TIG welding of AM300 to MDN250 plates using W2 filler. Weldments of AM300-W2-MDN250 showed the formation of Fusion zone (FZ) and dark band Heat affected Zones (HAZ) on both the sides of FZ. Weld specimens subjected to ageing times at 490°C for 3.5hrs and 6hrs have shown similar average hardness values in AM300, FZ and MDN250 as 700HV, 675HV and 650HV respectively. Tensile strength and %El of as-welded, aged (3.5hrs) and aged (6hrs) specimens were evaluated to be 925MPa, 2.7%; 1730MPa, 2.4%; 1850MPa, 1.4% respectively. The tensile strength of AM300-W2-MDN250 weldment aged to 3.5hrs is found to be higher than that of conventional MDN250 weldment, but with about 60% reduction in ductility. However, higher weld strength being the main criteria, the joining of AM300 to MDN250 can be considered as a viable option for relevant applications.
{"title":"Welding Studies and Characterisation of Additively Manufactured LPBF Maraging Steel","authors":"Ramesh Kumar Saride, Srinivas Vajjala, Brijesh Patel, Suraj Kumar, Rajesh Kumar, Laxminarayana Pappula, Jagan Reddy Ginuga","doi":"10.11648/j.ijmea.20231105.11","DOIUrl":"https://doi.org/10.11648/j.ijmea.20231105.11","url":null,"abstract":"Additive manufacturing (AM) comes under the category of advanced manufacturing techniques that enables the manufacture of complex shaped components with reduction in multi-part assemblies, production lead times and weight. Maraging steel is a strategic material for manufacturing of components such as rocket motor casings, bulkheads etc. in defence and aerospace sectors. Laser Powder Bed Fusion (LPBF) AM technique has been explored in fabrication of Maraging steel components for end-use applications. In many applications, additively manufactured maraging steel parts are required to be welded to conventional material and it is important to understand weldability of these materials and their characteristics to ensure good bonding between the parts. It is also necessary to assess how welding process may affect the microstructure and consequently the mechanical properties of the AM maraging steel. In the present study, welding of AM maraging steel AM300 with conventional MDN250 was explored. With the available optimized parameters, maraging steel plates (160x100x6mm<sup>3</sup>) were additively manufactured at low porosity without any defects of soot and spatter. The effect of heat treatment conditions on the volume fraction of reverted austenite in AM300 was also studied to arrive at an appropriate condition before carrying out the welding of AM300 plates. XRD and EBSD analysis revealed the formation of very fine reverted austenite in the as-deposited (AD) and Direct-aged (DA) conditions at the cell boundaries. Specimens when subjected to solution-treated and aged (STA) condition had almost eliminated the formation of reverted austenite at room temperature. Thus, the AM processed plates were subjected to solution treatment before carrying out the TIG welding of AM300 to MDN250 plates using W2 filler. Weldments of AM300-W2-MDN250 showed the formation of Fusion zone (FZ) and dark band Heat affected Zones (HAZ) on both the sides of FZ. Weld specimens subjected to ageing times at 490°C for 3.5hrs and 6hrs have shown similar average hardness values in AM300, FZ and MDN250 as 700HV, 675HV and 650HV respectively. Tensile strength and %El of as-welded, aged (3.5hrs) and aged (6hrs) specimens were evaluated to be 925MPa, 2.7%; 1730MPa, 2.4%; 1850MPa, 1.4% respectively. The tensile strength of AM300-W2-MDN250 weldment aged to 3.5hrs is found to be higher than that of conventional MDN250 weldment, but with about 60% reduction in ductility. However, higher weld strength being the main criteria, the joining of AM300 to MDN250 can be considered as a viable option for relevant applications.","PeriodicalId":471114,"journal":{"name":"International Journal of Mechanical Engineering and Applications","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136363008","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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