Pub Date : 2024-08-27DOI: 10.1177/14644207241277945
K Nehru, P Tamilselvam
In the present work, egg shell and Tungsten disulphide particles are reinforced in AZ31B alloy using friction stir process. Initially, the ES and WS2 particles are mixed at different weight ratios (25/75, 50/50 and 75/25) then are reinforced in AZ31B plates using a taper threaded FSP tool at rotation speed of 1000 rpm, axial load of 6 kN and traverse speed of 10 mm/min in hole method. The post macroscopic analysis showed that defect free hybrid surface composite is obtained with 75wt %ES and 25wt % WS2 particles reinforced in AZ31B alloy. The grain size is reduced from 15 µm to 5 µm due to the addition of 75wt% ES and 25wt% WS2 particles through FSP. The mechanical, corrosion and tribological responses of AZ31B/75ES/25WS2 hybrid surface composite are observed and are compared with FSPed AZ31B alloy without reinforcements and AZ31B base alloy. The microhardness is improved by 66% and 83% in FSPed AZ31B alloy and AZ31B/75ES/25WS2 hybrid surface composite respectively compared to the AZ31B base alloy. Similarly, the ultimate tensile strength is improved by 16% and 31% in FSPed AZ31B alloy and AZ31B/75ES/25WS2 hybrid surface composite respectively compared to the AZ31B base alloy but the % of elongation is decreased by 70% and 78% in FSPed AZ31B alloy and AZ31B/75ES/25WS2 hybrid surface composite respectively compared to the AZ31B base alloy. The corrosion rates of FSPed AZ31B alloy and AZ31B/75ES/25WS2 hybrid surface composite are decreased by 22% and 48% respectively compared to AZ31B base alloy. The dry sliding friction and wear responses are observed for AZ31B base alloy and AZ31B/75ES/25WS2 hybrid surface composite by varying the applied load (10 N, 20 N and 30 N) and sliding velocity (1.5 m/s, 2.6 m/s and 3.6 m/s) with constant sliding distance of 2000 m. In AZ31B base alloy, the wear mechanism is initially dominated by delamination and ploughing phenomena but at high sliding condition, the delaminated and worn out debris based tribolayer reduced the wear rate. In AZ31B/75ES/25WS2 hybrid surface composite, the wear mechanism is dominated by adhesive and delamination phenomena and the formed tribolayer decreased the wear rate at high sliding condition.
{"title":"Mechanical, corrosion and tribological behavior of friction stir processed AZ31B/egg shell /WS2 hybrid surface composite","authors":"K Nehru, P Tamilselvam","doi":"10.1177/14644207241277945","DOIUrl":"https://doi.org/10.1177/14644207241277945","url":null,"abstract":"In the present work, egg shell and Tungsten disulphide particles are reinforced in AZ31B alloy using friction stir process. Initially, the ES and WS<jats:sub>2</jats:sub> particles are mixed at different weight ratios (25/75, 50/50 and 75/25) then are reinforced in AZ31B plates using a taper threaded FSP tool at rotation speed of 1000 rpm, axial load of 6 kN and traverse speed of 10 mm/min in hole method. The post macroscopic analysis showed that defect free hybrid surface composite is obtained with 75wt %ES and 25wt % WS<jats:sub>2</jats:sub> particles reinforced in AZ31B alloy. The grain size is reduced from 15 µm to 5 µm due to the addition of 75wt% ES and 25wt% WS<jats:sub>2</jats:sub> particles through FSP. The mechanical, corrosion and tribological responses of AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite are observed and are compared with FSPed AZ31B alloy without reinforcements and AZ31B base alloy. The microhardness is improved by 66% and 83% in FSPed AZ31B alloy and AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite respectively compared to the AZ31B base alloy. Similarly, the ultimate tensile strength is improved by 16% and 31% in FSPed AZ31B alloy and AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite respectively compared to the AZ31B base alloy but the % of elongation is decreased by 70% and 78% in FSPed AZ31B alloy and AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite respectively compared to the AZ31B base alloy. The corrosion rates of FSPed AZ31B alloy and AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite are decreased by 22% and 48% respectively compared to AZ31B base alloy. The dry sliding friction and wear responses are observed for AZ31B base alloy and AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite by varying the applied load (10 N, 20 N and 30 N) and sliding velocity (1.5 m/s, 2.6 m/s and 3.6 m/s) with constant sliding distance of 2000 m. In AZ31B base alloy, the wear mechanism is initially dominated by delamination and ploughing phenomena but at high sliding condition, the delaminated and worn out debris based tribolayer reduced the wear rate. In AZ31B/75ES/25WS<jats:sub>2</jats:sub> hybrid surface composite, the wear mechanism is dominated by adhesive and delamination phenomena and the formed tribolayer decreased the wear rate at high sliding condition.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1177/14644207241276721
Marukurthi V N V Satyanarayana, Sagar Yanda, Kethavath Kranthi Kumar, Bade Venkata Suresh, Durga Janaki Venkatesh, Rajani Kanthreddy Kolagotla, Kumar Raja Gudaru
More than half of mechanical breakdowns stem from fatigue failure, often occurring suddenly and without warning. Friction stir processing (FSP) enhances the material's toughness and resilience to fatigue by refining its grain structure. This study investigates how multi-pass overlapping technique impacts the fatigue crack growth rate of FSPed Al-Cu alloy. Microstructural analysis revealed that the stir region exhibited uniformly dispersed and fragmented precipitates and finely recrystallized ultrafine grains. The hardness and strength were reduced, and ductility was enhanced after FSP due to high thermal cycling. Fatigue testing demonstrated a significant increase in fatigue life and reduced fatigue crack growth rate attributable to the combined effects of precipitation and grain refinement during cooling-assisted FSP. SEM examination of fatigue fracture surfaces revealed dimples indicative of ductile failure in the rapid crack propagation zone, while the steady-state propagation region displayed striation markings and secondary fractures.
{"title":"Effect of multi-pass overlapping friction stir processing on fatigue behavior of Al-Cu alloy","authors":"Marukurthi V N V Satyanarayana, Sagar Yanda, Kethavath Kranthi Kumar, Bade Venkata Suresh, Durga Janaki Venkatesh, Rajani Kanthreddy Kolagotla, Kumar Raja Gudaru","doi":"10.1177/14644207241276721","DOIUrl":"https://doi.org/10.1177/14644207241276721","url":null,"abstract":"More than half of mechanical breakdowns stem from fatigue failure, often occurring suddenly and without warning. Friction stir processing (FSP) enhances the material's toughness and resilience to fatigue by refining its grain structure. This study investigates how multi-pass overlapping technique impacts the fatigue crack growth rate of FSPed Al-Cu alloy. Microstructural analysis revealed that the stir region exhibited uniformly dispersed and fragmented precipitates and finely recrystallized ultrafine grains. The hardness and strength were reduced, and ductility was enhanced after FSP due to high thermal cycling. Fatigue testing demonstrated a significant increase in fatigue life and reduced fatigue crack growth rate attributable to the combined effects of precipitation and grain refinement during cooling-assisted FSP. SEM examination of fatigue fracture surfaces revealed dimples indicative of ductile failure in the rapid crack propagation zone, while the steady-state propagation region displayed striation markings and secondary fractures.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1177/14644207241269605
Huiwen Qi, Guangyang Lu, Dongmei Zhu, Guoyong Liu
A novel cellular structure is proposed based on bionic structure with negative Poisson's ratio characteristic, and the cell is periodically expanded in the in-plane direction to create a new honeycomb structure. The influence of gradient changes of the structural parameters on the load-bearing capacity and damping characteristics of the structure is investigated through a combination method of finite element numerical simulations and experiments. The results indicate that the concentric gradient arrangement of cell wall thickness and angle parameters, and the symmetrical gradient arrangement of cell height, wall thickness and angle parameters have the most significant influence on the static bearing capacity of the structure. In contrast, the gradient arrangement under the corner circle diameter has minimal effect on the static bearing capacity of the structure. Under the same conditions, the peak values of the transmissibility of C2 (large angle at constraint end and loading end, and smaller angle in the middle) and C3 structures (angle gradually increases from the loading end to the constraint end) are significantly reduced between the frequency 2 Hz and 1024 Hz. The peak values of the transmissibility of the structures C2 and C3 are respectively decreased by 20% and 25% compared to that of the non-gradient structure. This shows that the vibration damping effect of these two structures is better. The structure with the gradient change and the structure without the gradient change of the new honeycomb structure can both achieve certain vibration reduction and isolation from the middle to high frequency range.
{"title":"Mechanical properties of a novel negative Poisson's ratio gradient structure","authors":"Huiwen Qi, Guangyang Lu, Dongmei Zhu, Guoyong Liu","doi":"10.1177/14644207241269605","DOIUrl":"https://doi.org/10.1177/14644207241269605","url":null,"abstract":"A novel cellular structure is proposed based on bionic structure with negative Poisson's ratio characteristic, and the cell is periodically expanded in the in-plane direction to create a new honeycomb structure. The influence of gradient changes of the structural parameters on the load-bearing capacity and damping characteristics of the structure is investigated through a combination method of finite element numerical simulations and experiments. The results indicate that the concentric gradient arrangement of cell wall thickness and angle parameters, and the symmetrical gradient arrangement of cell height, wall thickness and angle parameters have the most significant influence on the static bearing capacity of the structure. In contrast, the gradient arrangement under the corner circle diameter has minimal effect on the static bearing capacity of the structure. Under the same conditions, the peak values of the transmissibility of C2 (large angle at constraint end and loading end, and smaller angle in the middle) and C3 structures (angle gradually increases from the loading end to the constraint end) are significantly reduced between the frequency 2 Hz and 1024 Hz. The peak values of the transmissibility of the structures C2 and C3 are respectively decreased by 20% and 25% compared to that of the non-gradient structure. This shows that the vibration damping effect of these two structures is better. The structure with the gradient change and the structure without the gradient change of the new honeycomb structure can both achieve certain vibration reduction and isolation from the middle to high frequency range.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1177/14644207241277511
P Senthil Kumar, Satishkumar S
The emergence of light-weight compounds has led to numerous research innovations in the field of composite materials. In order to find out how well materials work when they are exposed to different environmental conditions, this study looks at the mechanical and machining properties of natural fiber composite materials that have been chemically treated under different aging conditions. Epoxy resin and triethylenetetramine hardener were utilized to make composites, along with chemically treated pineapple fiber. Composite plates were fabricated using a manual layup method and post-cured under different aging conditions of 40 °C and 60 °C for 30 days, as well as immersion in sea water and rain water for the same duration. Despite undergoing aging conditions, the B-series specimens exhibited superior mechanical properties compared to untreated ones. The B-series specimens (B0, B1, B2, B3, and B4) showed rail shear and lap shear values ranging from approximately 19 MPa to 27 MPa and 15 MPa to 23 MPa, respectively. Additionally, the B-series specimens demonstrated higher fatigue life counts ranging from approximately 16,000 to 20,000 cycles, along with maximum stress values ranging from approximately 56 MPa to 70 MPa. Drilling macroscopic scans revealed that chemically treated specimens exhibited minimal fiber pull-out, dimensional stability, and improved bonding compared to untreated specimens. Overall, the study demonstrates that chemically treated fiber composites exhibit superior mechanical properties and machining characteristics, making them promising materials for various industrial applications, including automobiles, industrial, civil, and marine engineering, and the aviation sector.
{"title":"Effects of alkali-silane surface-grafted pineapple fibre on lamina delamination & drilling damage behaviour of aged epoxy composites under various water and temperature","authors":"P Senthil Kumar, Satishkumar S","doi":"10.1177/14644207241277511","DOIUrl":"https://doi.org/10.1177/14644207241277511","url":null,"abstract":"The emergence of light-weight compounds has led to numerous research innovations in the field of composite materials. In order to find out how well materials work when they are exposed to different environmental conditions, this study looks at the mechanical and machining properties of natural fiber composite materials that have been chemically treated under different aging conditions. Epoxy resin and triethylenetetramine hardener were utilized to make composites, along with chemically treated pineapple fiber. Composite plates were fabricated using a manual layup method and post-cured under different aging conditions of 40 °C and 60 °C for 30 days, as well as immersion in sea water and rain water for the same duration. Despite undergoing aging conditions, the B-series specimens exhibited superior mechanical properties compared to untreated ones. The B-series specimens (B0, B1, B2, B3, and B4) showed rail shear and lap shear values ranging from approximately 19 MPa to 27 MPa and 15 MPa to 23 MPa, respectively. Additionally, the B-series specimens demonstrated higher fatigue life counts ranging from approximately 16,000 to 20,000 cycles, along with maximum stress values ranging from approximately 56 MPa to 70 MPa. Drilling macroscopic scans revealed that chemically treated specimens exhibited minimal fiber pull-out, dimensional stability, and improved bonding compared to untreated specimens. Overall, the study demonstrates that chemically treated fiber composites exhibit superior mechanical properties and machining characteristics, making them promising materials for various industrial applications, including automobiles, industrial, civil, and marine engineering, and the aviation sector.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Considering the significance of sheet metal forming in various industries, metal sheets, and lightweight alloys find extensive applications. It is essential to predict the formability limit of sheets. Whereas the previous studies used the Nakazima test, this study aims to determine the forming limit diagram (FLD) numerically and experimentally using multipoint forming, considering the strain path's effect on formability. Also, it is compared with the conventional FLD obtained via the Nakazima test. The results show that multipoint forming improves sheet metal forming. The experimental FLD for an AL 2024-O sheet with a 12 mm pin size was found to have higher formability than that obtained from the Nakazima test. The effect of the polyurethane layer on the forming limit diagram was investigated. The experimental results showed that the polyurethane layer prevents local strain and increases the limits on the forming limit diagram. The numerical forming limit diagram was predicted by the second derivative method. Finally, the experimental results were compared with the numerical simulation results, showing that the results had an agreement above 90%. This method can be used as a reference for assessing the effectiveness of the multipoint forming technique.
{"title":"Multipoint forming process of aluminum sheet considering its forming limit diagram: Experimental and numerical investigations","authors":"Milad Aali Majidabad, Reza Khodayari, Habibolah Akbari, Behnam Davoodi, Ramin Hashemi","doi":"10.1177/14644207241276681","DOIUrl":"https://doi.org/10.1177/14644207241276681","url":null,"abstract":"Considering the significance of sheet metal forming in various industries, metal sheets, and lightweight alloys find extensive applications. It is essential to predict the formability limit of sheets. Whereas the previous studies used the Nakazima test, this study aims to determine the forming limit diagram (FLD) numerically and experimentally using multipoint forming, considering the strain path's effect on formability. Also, it is compared with the conventional FLD obtained via the Nakazima test. The results show that multipoint forming improves sheet metal forming. The experimental FLD for an AL 2024-O sheet with a 12 mm pin size was found to have higher formability than that obtained from the Nakazima test. The effect of the polyurethane layer on the forming limit diagram was investigated. The experimental results showed that the polyurethane layer prevents local strain and increases the limits on the forming limit diagram. The numerical forming limit diagram was predicted by the second derivative method. Finally, the experimental results were compared with the numerical simulation results, showing that the results had an agreement above 90%. This method can be used as a reference for assessing the effectiveness of the multipoint forming technique.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1177/14644207241277406
Raphaela März, Peter Hetz, Dominic Bartels, Michael Schmidt, Marion Merklein
In order to reduce CO2 emissions in production industry, the combination of several manufacturing processes is coming to the fore. One example is the combination of metal additive manufacturing with the forming technology, whereby the advantages of both process technologies can be used. The process combination can be applied to produce hybrid barrel sleeves, for example. Using a laser-based directed energy deposition (DED-LB/M), a circular coating is first applied to a blank, which is then deep-drawn in a second step. The additive layer serves as a wear-resistant coating. One way to increase process understanding for this process combination is numerical simulation. An important part of setting up the simulation model is characterizing the material in terms of its mechanical behavior. In order to avoid long building times, small sample geometries are suitable for characterizing the additive material. In the context of the paper, the upsetting test is therefore carried out with miniaturized specimens, whereby not only the base material Bainidur AM but also the addition of tungsten carbide microparticles and carbon nanoparticles is investigated. The in-situ modification of the material significantly increases the yield strength, but at the same time reduces the ductility. The microhardness of the material is also increased by the addition of carbon or tungsten carbide.
{"title":"Characterization of an additively manufactured coating using an upsetting test with miniaturized cylindrical specimen","authors":"Raphaela März, Peter Hetz, Dominic Bartels, Michael Schmidt, Marion Merklein","doi":"10.1177/14644207241277406","DOIUrl":"https://doi.org/10.1177/14644207241277406","url":null,"abstract":"In order to reduce CO<jats:sub>2</jats:sub> emissions in production industry, the combination of several manufacturing processes is coming to the fore. One example is the combination of metal additive manufacturing with the forming technology, whereby the advantages of both process technologies can be used. The process combination can be applied to produce hybrid barrel sleeves, for example. Using a laser-based directed energy deposition (DED-LB/M), a circular coating is first applied to a blank, which is then deep-drawn in a second step. The additive layer serves as a wear-resistant coating. One way to increase process understanding for this process combination is numerical simulation. An important part of setting up the simulation model is characterizing the material in terms of its mechanical behavior. In order to avoid long building times, small sample geometries are suitable for characterizing the additive material. In the context of the paper, the upsetting test is therefore carried out with miniaturized specimens, whereby not only the base material Bainidur AM but also the addition of tungsten carbide microparticles and carbon nanoparticles is investigated. The in-situ modification of the material significantly increases the yield strength, but at the same time reduces the ductility. The microhardness of the material is also increased by the addition of carbon or tungsten carbide.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1177/14644207241272840
Jpm Pragana, Rfv Sampaio, I. Bragança, Cma Silva, CV Nielsen, P. Martins
This paper focuses on the development of a finite element computer software to perform macro-scale thermo-mechanical simulations of wire-arc additive manufacturing (WAAM). The emphasis is placed on various aspects of computer implementation, such as modeling the heat source, incorporating an element birth approach to replicate material deposition, and ensuring compatibility of solution time increments with the wire feed rate, travel speed of the heat source and melt pool volume. Thermal strains are also included due to their impact on residual stresses and distortions of the built parts after finishing material deposition. Experiments consisting of single bead, multi-layer deposition of AISI 316L stainless steel along linear paths are utilized to validate the predicted temperature distribution over time and evaluate the computed geometry and distortions of the deposited vertical walls after unclamping. Microstructure observations of samples extracted from the walls combined with finite element estimates of the temperature gradient help understand the influence of temperature history on the morphology and orientation of columnar grain growth.
{"title":"Macro-scale finite element simulation of wire-arc additive manufacturing","authors":"Jpm Pragana, Rfv Sampaio, I. Bragança, Cma Silva, CV Nielsen, P. Martins","doi":"10.1177/14644207241272840","DOIUrl":"https://doi.org/10.1177/14644207241272840","url":null,"abstract":"This paper focuses on the development of a finite element computer software to perform macro-scale thermo-mechanical simulations of wire-arc additive manufacturing (WAAM). The emphasis is placed on various aspects of computer implementation, such as modeling the heat source, incorporating an element birth approach to replicate material deposition, and ensuring compatibility of solution time increments with the wire feed rate, travel speed of the heat source and melt pool volume. Thermal strains are also included due to their impact on residual stresses and distortions of the built parts after finishing material deposition. Experiments consisting of single bead, multi-layer deposition of AISI 316L stainless steel along linear paths are utilized to validate the predicted temperature distribution over time and evaluate the computed geometry and distortions of the deposited vertical walls after unclamping. Microstructure observations of samples extracted from the walls combined with finite element estimates of the temperature gradient help understand the influence of temperature history on the morphology and orientation of columnar grain growth.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.1177/14644207241269635
Jianchun Wang, Mehdi Zarei
This paper investigates the vibrational characteristics of lattice-core sandwich annular spherical shells. An effective analytical model, based on the Smeared Stiffener technique, is employed to integrate the stiffness contributions of the core with those of the shells. Helical stiffeners are modeled as beams capable of bearing axial forces and bending moments. The governing equations are derived from Donnell's classical thin shell theory. The Galerkin method is applied to extract the natural frequencies. To validate the analytical results and conduct a comprehensive parametric study, a 3D finite element model is developed using ABAQUS CAE software. Comparisons demonstrate a satisfactory agreement between the analytical and numerical results. Additionally, the effects of the spherical shell's geometric parameters, lamination angle, stiffener orientation angle, and various lattice core configurations are examined.
{"title":"Analysis of vibration characteristics of lattice-core sandwich annular spherical shells","authors":"Jianchun Wang, Mehdi Zarei","doi":"10.1177/14644207241269635","DOIUrl":"https://doi.org/10.1177/14644207241269635","url":null,"abstract":"This paper investigates the vibrational characteristics of lattice-core sandwich annular spherical shells. An effective analytical model, based on the Smeared Stiffener technique, is employed to integrate the stiffness contributions of the core with those of the shells. Helical stiffeners are modeled as beams capable of bearing axial forces and bending moments. The governing equations are derived from Donnell's classical thin shell theory. The Galerkin method is applied to extract the natural frequencies. To validate the analytical results and conduct a comprehensive parametric study, a 3D finite element model is developed using ABAQUS CAE software. Comparisons demonstrate a satisfactory agreement between the analytical and numerical results. Additionally, the effects of the spherical shell's geometric parameters, lamination angle, stiffener orientation angle, and various lattice core configurations are examined.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An approach to modeling creep fracture under a complex stress state using the Finite Element Method is proposed. The model of the turbine blade root was studied. The methodology of the transition in the analysis from the general 3D to the 2D stress state is proposed. For the models of the roots, the characteristics of the damage accumulation were obtained and the analysis of subsequent fracture in roots made of different materials was performed.The novel results of the description the creep fracture behavior after the period of damage accumulation were obtained. Based on the analysis of the numerical results, it was established that for different materials qualitatively different fracture processes occur in different places of the blade root. They were as follows: the fracture with separation of the main part of the root between the lower teeth; destruction of a separate tooth with a transition inside the root, as well as of a separate tooth jointly with the root’s lower part. A novel approach to obtaining the form of an equation for description the current length of a creep crack by use of numerical results is proposed.
{"title":"Creep damage and fracture of turbine blade roots","authors":"Dmytro Breslavsky, Volodymyr Mietielov, Alyona Senko, Oksana Tatarinova, Ihor Palkov, Holm Altenbach","doi":"10.1177/14644207241269616","DOIUrl":"https://doi.org/10.1177/14644207241269616","url":null,"abstract":"An approach to modeling creep fracture under a complex stress state using the Finite Element Method is proposed. The model of the turbine blade root was studied. The methodology of the transition in the analysis from the general 3D to the 2D stress state is proposed. For the models of the roots, the characteristics of the damage accumulation were obtained and the analysis of subsequent fracture in roots made of different materials was performed.The novel results of the description the creep fracture behavior after the period of damage accumulation were obtained. Based on the analysis of the numerical results, it was established that for different materials qualitatively different fracture processes occur in different places of the blade root. They were as follows: the fracture with separation of the main part of the root between the lower teeth; destruction of a separate tooth with a transition inside the root, as well as of a separate tooth jointly with the root’s lower part. A novel approach to obtaining the form of an equation for description the current length of a creep crack by use of numerical results is proposed.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-06DOI: 10.1177/14644207241269567
Ravi Vijaykumar Sevak, Ramesh Gupta Burela, Gaurav Arora, Ankit Gupta
The present study deals with the fabrication of hybrid composites using biodegradable and ecologically friendly natural fibers and a recyclable thermoplastic matrix. Pure and hybrid natural fiber composites of high-density polyethylene (HDPE) with Kenaf and Ramie fiber, 20 wt%, were fabricated using microwave-assisted compression molding. The composite's mechanical characterization was performed using tensile, flexural, impact, and hardness tests. X-ray diffraction was done to investigate the crystallinity percentage, and scanning electron microscopy of fractured surfaces was performed to determine failure mechanisms. The hybrid composite of HDPE/Ramie and Kenaf exhibited the highest ultimate tensile strength (UTS) at 29.3 ± 1.2 MPa, surpassing HDPE/Kenaf (21.6 ± 1.1 MPa) and HDPE/Ramie (24.3 ± 1.4 MPa) composites. In terms of flexural strength, HDPE/Ramie demonstrated the highest at 19.9 ± 1.5 MPa, while HDPE/Kenaf had the lowest at 18 ± 1.1 MPa. The hybrid composite's flexural strength was intermediate at 19 ± 1.3 MPa. Impact strength followed a similar trend, with the hybrid composite leading at 40.2 KJ/m2, followed by HDPE/Ramie (26.9 KJ/m2) and HDPE/Kenaf (12.3 KJ/m2). Hardness tests revealed the highest hardness in the hybrid composite and the lowest in HDPE/Kenaf. A computational study has been performed to develop a model for predicting the hybrid composites. A strong agreement between both studies has been observed. The developed composite is deemed suitable for various light-duty applications, such as roofing, car interior panels, and mobile covers, offering potential benefits in reducing carbon footprint.
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