A. Kalizhanova, U. Imanbekova, A. Kozbakova, A. Imanbekova, A. Utegenova
This paper presents the developed model of dynamics of the physicochemical processes of electromelting of copper concentrates, which was obtained taking into account the available a priori information, which makes allowance for the main features of an object and describes the change of the basic variables of the process state (quantitative aspects of material flows and power, the composition of charge, matte, and slag). Such a model can be used in the field of automation of technological processes in metallurgical and mechanical engineering, and manufacturing. Due to the complexities of the technological process, it was advisable to use classical methods.
{"title":"Optimal Control of the Dynamics of Physical and Chemical Processes of Blending and Melting of Copper Concentrates","authors":"A. Kalizhanova, U. Imanbekova, A. Kozbakova, A. Imanbekova, A. Utegenova","doi":"10.46300/9104.2024.18.4","DOIUrl":"https://doi.org/10.46300/9104.2024.18.4","url":null,"abstract":"This paper presents the developed model of dynamics of the physicochemical processes of electromelting of copper concentrates, which was obtained taking into account the available a priori information, which makes allowance for the main features of an object and describes the change of the basic variables of the process state (quantitative aspects of material flows and power, the composition of charge, matte, and slag). Such a model can be used in the field of automation of technological processes in metallurgical and mechanical engineering, and manufacturing. Due to the complexities of the technological process, it was advisable to use classical methods.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141828982","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}
Dinh Van Thanh, Vu Duc Binh, Vu Duong, Lưu Anh Tùng, Tran Quoc Hung
This paper presents the findings from the multi-criteria decision-making (MCDM) approach study on selecting the best dressing mode (DM) for surface grinding (SG) Hardox 500. The study employed the Simple Additive Weighting (SAW) approach to solve the MCDM problem, and the Entropy method was utilized to estimate the weights of the criteria. Moreover, material removal rate (MRR) and surface roughness (RS) were selected as the two criteria for the investigation. Additionally, the five dressing parameters - fine dressing depth (Tf), rough dressing depth (Tr), rough dressing times (Nr), and non-feeding dressing (Nnon) - were investigated. 16 L16 (44x21) experimental runs were also designed and executed. For the first time, the MCDM for the SG process of Hardox 500 has been successfully solved using the SAW approach. From the results of the work, alternative No. 5 is the best option and the ideal input parameters (IP) of the dressing process were proposed.
{"title":"Application of SAW Technique for Finding the Best Dressing Mode for Surface Grinding Hardox 500","authors":"Dinh Van Thanh, Vu Duc Binh, Vu Duong, Lưu Anh Tùng, Tran Quoc Hung","doi":"10.46300/9104.2024.18.3","DOIUrl":"https://doi.org/10.46300/9104.2024.18.3","url":null,"abstract":"This paper presents the findings from the multi-criteria decision-making (MCDM) approach study on selecting the best dressing mode (DM) for surface grinding (SG) Hardox 500. The study employed the Simple Additive Weighting (SAW) approach to solve the MCDM problem, and the Entropy method was utilized to estimate the weights of the criteria. Moreover, material removal rate (MRR) and surface roughness (RS) were selected as the two criteria for the investigation. Additionally, the five dressing parameters - fine dressing depth (Tf), rough dressing depth (Tr), rough dressing times (Nr), and non-feeding dressing (Nnon) - were investigated. 16 L16 (44x21) experimental runs were also designed and executed. For the first time, the MCDM for the SG process of Hardox 500 has been successfully solved using the SAW approach. From the results of the work, alternative No. 5 is the best option and the ideal input parameters (IP) of the dressing process were proposed.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371388","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 study is devoted to the issue of the destruction of a body with an inclined crack during rotation. A mathematical model for calculating stress intensity factors in a rectangular plate with an inclined crack under the influence of centrifugal tensile forces during rotation around an axis lying in the plane of the plate is constructed in the article. Based on the equations of the theory of elasticity and the principles of brittle fracture mechanics, relationships were obtained that relate the stress intensity factors of type I and II, the rotation speed and geometry of the plate, as well as the parameters of the crack: length, angle of inclination to the axis of rotation, distance from the axis of rotation to the crack. The complexity of the study is because the plate in question with an inclined crack is under the action of mass forces. Therefore, the values of the effective stresses are not the same along the crack edge. Accordingly, stress intensity factors will depend on the location of the crack relative to the axis of rotation. The influence of the crack location and plate rotation speed on the change in stress intensity factor values is analyzed based on the results obtained. As the distance from the axis of rotation to the crack increases, the values of the stress intensity factors decrease. As the plate rotation frequency increases, the stress intensity coefficients increase according to a parabolic law. The results of the study can be used to assess the limit state of the rotating blades of a gas turbine engine in the presence of an inclined crack. The mathematical model can find practical application for assessing the critical speed regime of blade rotation in the presence of cracks of various lengths and angles of inclination to the rotation axis.
该研究专门探讨了带有倾斜裂纹的物体在旋转过程中的破坏问题。文章构建了一个数学模型，用于计算带倾斜裂纹的矩形板在绕位于板平面内的轴旋转时离心拉力影响下的应力强度因子。根据弹性理论方程和脆性断裂力学原理，得出了 I 型和 II 型应力强度因子、旋转速度和板的几何形状以及裂纹参数（长度、与旋转轴的倾斜角、旋转轴到裂纹的距离）之间的关系。研究的复杂性在于带有倾斜裂纹的板受到质量力的作用。因此，沿裂纹边缘的有效应力值并不相同。因此，应力强度系数将取决于裂纹相对于旋转轴的位置。根据所得结果，分析了裂纹位置和板旋转速度对应力强度因子值变化的影响。随着旋转轴到裂纹距离的增加，应力强度因子值也随之减小。随着钢板旋转频率的增加，应力强度系数按照抛物线规律增加。研究结果可用于评估燃气涡轮发动机旋转叶片在出现倾斜裂纹时的极限状态。该数学模型可实际应用于评估存在不同长度和与旋转轴倾斜角度的裂纹时叶片旋转的临界速度状态。
{"title":"Model for Calculating Stress Intensity Factors for an Inclined Crack at the Leading Edge of a Gas Turbine Engine Blade Under the Influence of Centrifugal Forces","authors":"I. K. Andrianov, E. Chepurnova","doi":"10.46300/9104.2024.18.2","DOIUrl":"https://doi.org/10.46300/9104.2024.18.2","url":null,"abstract":"The study is devoted to the issue of the destruction of a body with an inclined crack during rotation. A mathematical model for calculating stress intensity factors in a rectangular plate with an inclined crack under the influence of centrifugal tensile forces during rotation around an axis lying in the plane of the plate is constructed in the article. Based on the equations of the theory of elasticity and the principles of brittle fracture mechanics, relationships were obtained that relate the stress intensity factors of type I and II, the rotation speed and geometry of the plate, as well as the parameters of the crack: length, angle of inclination to the axis of rotation, distance from the axis of rotation to the crack. The complexity of the study is because the plate in question with an inclined crack is under the action of mass forces. Therefore, the values of the effective stresses are not the same along the crack edge. Accordingly, stress intensity factors will depend on the location of the crack relative to the axis of rotation. The influence of the crack location and plate rotation speed on the change in stress intensity factor values is analyzed based on the results obtained. As the distance from the axis of rotation to the crack increases, the values of the stress intensity factors decrease. As the plate rotation frequency increases, the stress intensity coefficients increase according to a parabolic law. The results of the study can be used to assess the limit state of the rotating blades of a gas turbine engine in the presence of an inclined crack. The mathematical model can find practical application for assessing the critical speed regime of blade rotation in the presence of cracks of various lengths and angles of inclination to the rotation axis.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"09 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140984134","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. Kalizhanova, M. Kunelbayev, Waldemar Wojcik, A. Kozbakova, Baydaulet Urmashev, Assiyat Akhustova
The article describes the optical elements of signal demodulation and polling systems from photonic pressure sensors on inclined fiber Bragg gratings, which are often used to measure the refractive index (RI). A new design of a photonic fiber-optic Bragg pressure sensor with an inclined lattice has been developed, which is connected to standard multimode fibers with an inclined Bragg lattice connected to a metal diaphragm, which is a deformed inclined cantilever. The light source is polarized using the first polarizer and directed to the photonic crystal fiber in such a way as to excite multimode fibers. In this work, a method was developed for determining the optical elements of the spectral contour length system, which consists of setting the cut-off wavelength and then determining the accompanying refractive index. An experimental study determined the curve of the chain length change in the set. To process random signals, the spatial correlation method is used in combination with an approach to digital images based on the number of lanes and the direction of movement. The experimental results differ from the theoretical ones by about 4%. The developed correlation method reflects frequency as well as randomness, it is used in the photographic process together with the image correction given in this document.
{"title":"Demodulation and Vibration Signal Systems for Photonic Fiber Optic Pressure Sensor","authors":"A. Kalizhanova, M. Kunelbayev, Waldemar Wojcik, A. Kozbakova, Baydaulet Urmashev, Assiyat Akhustova","doi":"10.46300/9104.2024.18.1","DOIUrl":"https://doi.org/10.46300/9104.2024.18.1","url":null,"abstract":"The article describes the optical elements of signal demodulation and polling systems from photonic pressure sensors on inclined fiber Bragg gratings, which are often used to measure the refractive index (RI). A new design of a photonic fiber-optic Bragg pressure sensor with an inclined lattice has been developed, which is connected to standard multimode fibers with an inclined Bragg lattice connected to a metal diaphragm, which is a deformed inclined cantilever. The light source is polarized using the first polarizer and directed to the photonic crystal fiber in such a way as to excite multimode fibers. In this work, a method was developed for determining the optical elements of the spectral contour length system, which consists of setting the cut-off wavelength and then determining the accompanying refractive index. An experimental study determined the curve of the chain length change in the set. To process random signals, the spatial correlation method is used in combination with an approach to digital images based on the number of lanes and the direction of movement. The experimental results differ from the theoretical ones by about 4%. The developed correlation method reflects frequency as well as randomness, it is used in the photographic process together with the image correction given in this document.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"4 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139856904","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. Kalizhanova, M. Kunelbayev, Waldemar Wojcik, A. Kozbakova, Baydaulet Urmashev, Assiyat Akhustova
The article describes the optical elements of signal demodulation and polling systems from photonic pressure sensors on inclined fiber Bragg gratings, which are often used to measure the refractive index (RI). A new design of a photonic fiber-optic Bragg pressure sensor with an inclined lattice has been developed, which is connected to standard multimode fibers with an inclined Bragg lattice connected to a metal diaphragm, which is a deformed inclined cantilever. The light source is polarized using the first polarizer and directed to the photonic crystal fiber in such a way as to excite multimode fibers. In this work, a method was developed for determining the optical elements of the spectral contour length system, which consists of setting the cut-off wavelength and then determining the accompanying refractive index. An experimental study determined the curve of the chain length change in the set. To process random signals, the spatial correlation method is used in combination with an approach to digital images based on the number of lanes and the direction of movement. The experimental results differ from the theoretical ones by about 4%. The developed correlation method reflects frequency as well as randomness, it is used in the photographic process together with the image correction given in this document.
{"title":"Demodulation and Vibration Signal Systems for Photonic Fiber Optic Pressure Sensor","authors":"A. Kalizhanova, M. Kunelbayev, Waldemar Wojcik, A. Kozbakova, Baydaulet Urmashev, Assiyat Akhustova","doi":"10.46300/9104.2024.18.1","DOIUrl":"https://doi.org/10.46300/9104.2024.18.1","url":null,"abstract":"The article describes the optical elements of signal demodulation and polling systems from photonic pressure sensors on inclined fiber Bragg gratings, which are often used to measure the refractive index (RI). A new design of a photonic fiber-optic Bragg pressure sensor with an inclined lattice has been developed, which is connected to standard multimode fibers with an inclined Bragg lattice connected to a metal diaphragm, which is a deformed inclined cantilever. The light source is polarized using the first polarizer and directed to the photonic crystal fiber in such a way as to excite multimode fibers. In this work, a method was developed for determining the optical elements of the spectral contour length system, which consists of setting the cut-off wavelength and then determining the accompanying refractive index. An experimental study determined the curve of the chain length change in the set. To process random signals, the spatial correlation method is used in combination with an approach to digital images based on the number of lanes and the direction of movement. The experimental results differ from the theoretical ones by about 4%. The developed correlation method reflects frequency as well as randomness, it is used in the photographic process together with the image correction given in this document.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"21 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139797138","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 : 2023-11-20DOI: 10.46300/9104.2023.17.14
F. Djamaluddin
The structural dynamic features of a sandwich foam core structure with core and surface thicknesses are examined to increase the structure's resistance to vibration. The thickness of the core and surface of the sandwich foam core structure are defined as design variables in the optimization function of natural frequency parameters. The finite element analysis program FEA software was used for the analyses. The multi-objective optimization problem using RMS. The derived natural frequencies are compared with the outcomes of the experiments to validate the numerical model. The calculated natural frequencies are compared with the outcomes of the experiments to validate the numerical model. The structural optimization is then completed, using a sandwich foam core structure. The results show that the Aluminium Layer and foam core Thicknesses (m) are 0.0086 and 0,0357 m respectively
{"title":"Optimization of Free Vibration for Sandwich Foam Core","authors":"F. Djamaluddin","doi":"10.46300/9104.2023.17.14","DOIUrl":"https://doi.org/10.46300/9104.2023.17.14","url":null,"abstract":"The structural dynamic features of a sandwich foam core structure with core and surface thicknesses are examined to increase the structure's resistance to vibration. The thickness of the core and surface of the sandwich foam core structure are defined as design variables in the optimization function of natural frequency parameters. The finite element analysis program FEA software was used for the analyses. The multi-objective optimization problem using RMS. The derived natural frequencies are compared with the outcomes of the experiments to validate the numerical model. The calculated natural frequencies are compared with the outcomes of the experiments to validate the numerical model. The structural optimization is then completed, using a sandwich foam core structure. The results show that the Aluminium Layer and foam core Thicknesses (m) are 0.0086 and 0,0357 m respectively","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255029","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 : 2023-10-24DOI: 10.46300/9104.2023.17.13
Aliya Kalizhanova, Ainur Kozbakova, Murat Kunelbayev, Zhalau Aitkulov
Natural disasters, in particular earthquakes, can damage bridges, tunnels, dams, high-rise buildings, railways, oil platforms, buildings, and pipelines with catastrophic humanitarian, social, economic, and environmental consequences. Thus, automatic assessment of damage to industrial and civil construction structures after an earthquake in real-time or on request is necessary for early emergency response, effective preparation of rescue plans, and mitigation of these catastrophic consequences. The article presents the use of a system of distributed fiber-optic sensors based on Bragg fiber arrays, which will allow periodic measurements and monitoring of the condition of structures, assessing trends in its technical condition and thereby facilitating the identification of possible threats. The given research presents assembling and testing optoelectronic systems to record and process signals from fiber-optic sensors. The main optoelectronic systems to record and process the signals from fiber-optic sensors are light source controllers and optical power detectors. There was an assembled controller diagram, which apart from the light source includes the current source for its adequate operation, as well as the systems necessary for stabilizing its working point. The scheme was modeled for specifying nominal and maximum operation criteria. Construction has been designed in a way, that the light source controller includes structures of the current regulation and stabilization SLED (super luminescent diode) and temperature stabilization. Apart from that, there was assembled the microsystem of the optical power detector additionally to the light detector, which includes the microsystems of intensification and filtration of the signal measured, processing analog data into digital form, and microcontroller, used for preliminary data analysis. Data of optoelectronic systems diagram to record and process the signals from fiber-optic sensors has high response speed, low noise level, and sufficient progress. type your abstract here.
{"title":"Development of an Optoelectronic System for Recording and Processing Signals From Fiber-optic Sensors","authors":"Aliya Kalizhanova, Ainur Kozbakova, Murat Kunelbayev, Zhalau Aitkulov","doi":"10.46300/9104.2023.17.13","DOIUrl":"https://doi.org/10.46300/9104.2023.17.13","url":null,"abstract":"Natural disasters, in particular earthquakes, can damage bridges, tunnels, dams, high-rise buildings, railways, oil platforms, buildings, and pipelines with catastrophic humanitarian, social, economic, and environmental consequences. Thus, automatic assessment of damage to industrial and civil construction structures after an earthquake in real-time or on request is necessary for early emergency response, effective preparation of rescue plans, and mitigation of these catastrophic consequences. The article presents the use of a system of distributed fiber-optic sensors based on Bragg fiber arrays, which will allow periodic measurements and monitoring of the condition of structures, assessing trends in its technical condition and thereby facilitating the identification of possible threats. The given research presents assembling and testing optoelectronic systems to record and process signals from fiber-optic sensors. The main optoelectronic systems to record and process the signals from fiber-optic sensors are light source controllers and optical power detectors. There was an assembled controller diagram, which apart from the light source includes the current source for its adequate operation, as well as the systems necessary for stabilizing its working point. The scheme was modeled for specifying nominal and maximum operation criteria. Construction has been designed in a way, that the light source controller includes structures of the current regulation and stabilization SLED (super luminescent diode) and temperature stabilization. Apart from that, there was assembled the microsystem of the optical power detector additionally to the light detector, which includes the microsystems of intensification and filtration of the signal measured, processing analog data into digital form, and microcontroller, used for preliminary data analysis. Data of optoelectronic systems diagram to record and process the signals from fiber-optic sensors has high response speed, low noise level, and sufficient progress. type your abstract here.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"10 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135273072","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 usage of non-destructive techniques for structure's state assessment is highly desirable because they offer the possibility to monitor continuously and in a non-invasive manner the sign of failures of any structure. Among the several techniques proposed over the years, Acoustic Emission (AE) seems very promising. Such a technique, which applies to various materials, consents to the evaluation of micro-fractures generated during failure by detecting their acoustic emission through sensors located on the surface of the material itself. Concrete beam failure is suitable for such kind of procedure. It has been widely investigated through AE, but despite the many literature contributes, there still is a scarcity of practical applications on real structures, and no consensus on protocols. In this work, an AE technique has been paired with a four-point bending test to try and find a robust and reliable experimental setup for AE application on concrete beams. Results show a proper classification of the occurring cracks, which change according to different zones of the concrete beam and different load values. Axial crack signals exhibit different features concerning shear crack ones. In such a way, the categorization of damages can be performed and crosschecked with the theoretical expectations. All these results suggest that the proposed setup can be used as a possible protocol for practical AE measurements.
{"title":"Cracks Classification using Acoustic Emission Technique on a Reinforced Concrete Beam","authors":"Antonella Bianca Francavilla, Paola Barra, Domenico Rossi, Massimo Latour, Claudio Guarnaccia, Gianvittorio Rizzano","doi":"10.46300/9104.2023.17.12","DOIUrl":"https://doi.org/10.46300/9104.2023.17.12","url":null,"abstract":"The usage of non-destructive techniques for structure's state assessment is highly desirable because they offer the possibility to monitor continuously and in a non-invasive manner the sign of failures of any structure. Among the several techniques proposed over the years, Acoustic Emission (AE) seems very promising. Such a technique, which applies to various materials, consents to the evaluation of micro-fractures generated during failure by detecting their acoustic emission through sensors located on the surface of the material itself. Concrete beam failure is suitable for such kind of procedure. It has been widely investigated through AE, but despite the many literature contributes, there still is a scarcity of practical applications on real structures, and no consensus on protocols. In this work, an AE technique has been paired with a four-point bending test to try and find a robust and reliable experimental setup for AE application on concrete beams. Results show a proper classification of the occurring cracks, which change according to different zones of the concrete beam and different load values. Axial crack signals exhibit different features concerning shear crack ones. In such a way, the categorization of damages can be performed and crosschecked with the theoretical expectations. All these results suggest that the proposed setup can be used as a possible protocol for practical AE measurements.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135826564","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 : 2023-08-01DOI: 10.46300/9104.2023.17.11
H. Susanti, Husneni Mukhtar, S. Suprijanto, Willy Anugrah Cahyadi
In Indonesia, the prevalence of osteoporosis is high. Given the economic burden it may impose on the population, this condition must be taken seriously. Dual-energy X-ray absorptiometry is the gold standard for diagnosing osteoporosis (DEXA). However, due to its high cost, non-portability, and radiation risk, DEXA cannot be applied to large populations. An alternative method for evaluating bone quality is ultrasound. It is more affordable, portable, and has no radiation risk. In this preliminary study, an A-mode ultrasound spectroscopy prototype for assessing the density of a 3D-printed bone model is designed. A single-element transducer (Transmit-Tx/Receive-Rx), a reconfigurable and modular FPGA-based ultrasound beamformer system, and a Raspberry Pi 3 are the system's control units. The raw radio frequency (RF) signal is acquired from three variations of density of the 3D-printed bone model, i.e., 100%, 60%, and 40%, to represent normal bone, osteopenia, and osteoporosis. The designed prototype can adequately characterize the mechanical wave scattering pattern of the 3D-printed bone model indicated by the increased tendency in the maximum amplitude when the density of the bone model is increasing. The tendency is the opposite for delay time and Power Spectral Density (PSD). These three signal parameters are potential candidate parameters to represent bone density. For future work, the selected candidate parameters can later be used as reference values while adding a significant data so that a machine learning method can be employed to extract representative features of bone density level, i.e., normal bone, osteopenia, and osteoporosis.
{"title":"Initial Study of A-mode Ultrasound Spectroscopy Through Mechanical Wave Scattering Phenomenon for Measuring 3D-printed Bone Model Density","authors":"H. Susanti, Husneni Mukhtar, S. Suprijanto, Willy Anugrah Cahyadi","doi":"10.46300/9104.2023.17.11","DOIUrl":"https://doi.org/10.46300/9104.2023.17.11","url":null,"abstract":"In Indonesia, the prevalence of osteoporosis is high. Given the economic burden it may impose on the population, this condition must be taken seriously. Dual-energy X-ray absorptiometry is the gold standard for diagnosing osteoporosis (DEXA). However, due to its high cost, non-portability, and radiation risk, DEXA cannot be applied to large populations. An alternative method for evaluating bone quality is ultrasound. It is more affordable, portable, and has no radiation risk. In this preliminary study, an A-mode ultrasound spectroscopy prototype for assessing the density of a 3D-printed bone model is designed. A single-element transducer (Transmit-Tx/Receive-Rx), a reconfigurable and modular FPGA-based ultrasound beamformer system, and a Raspberry Pi 3 are the system's control units. The raw radio frequency (RF) signal is acquired from three variations of density of the 3D-printed bone model, i.e., 100%, 60%, and 40%, to represent normal bone, osteopenia, and osteoporosis. The designed prototype can adequately characterize the mechanical wave scattering pattern of the 3D-printed bone model indicated by the increased tendency in the maximum amplitude when the density of the bone model is increasing. The tendency is the opposite for delay time and Power Spectral Density (PSD). These three signal parameters are potential candidate parameters to represent bone density. For future work, the selected candidate parameters can later be used as reference values while adding a significant data so that a machine learning method can be employed to extract representative features of bone density level, i.e., normal bone, osteopenia, and osteoporosis.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42959370","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 : 2023-07-24DOI: 10.46300/9104.2023.17.10
Z. Kala
The article introduces an innovative approach to modelling initial geometric imperfections in steel plane frames. Initial imperfections are introduced using the analysis of normalised deformations of elastic buckling modes. The scale of these modes is assessed by applying Shannon entropy and potential energy analysis. The presented case study demonstrates a decreasing scale of the elastic buckling modes. The entropy computed from the deformation reveals a new perspective on buckling modes and provides a more profound understanding of steel frame behaviour. The case study results indicate that anti-symmetric buckling modes exhibit higher entropy than symmetric buckling modes. This entropy-based analysis enables the differentiation between symmetric and anti-symmetric buckling modes, which is particularly valuable when the critical buckling loads of sway and non-sway buckling modes are closely aligned or overlap.
{"title":"Modelling Initial Geometric Imperfections of Steel Plane Frames Using Entropy and Eigenmodes","authors":"Z. Kala","doi":"10.46300/9104.2023.17.10","DOIUrl":"https://doi.org/10.46300/9104.2023.17.10","url":null,"abstract":"The article introduces an innovative approach to modelling initial geometric imperfections in steel plane frames. Initial imperfections are introduced using the analysis of normalised deformations of elastic buckling modes. The scale of these modes is assessed by applying Shannon entropy and potential energy analysis. The presented case study demonstrates a decreasing scale of the elastic buckling modes. The entropy computed from the deformation reveals a new perspective on buckling modes and provides a more profound understanding of steel frame behaviour. The case study results indicate that anti-symmetric buckling modes exhibit higher entropy than symmetric buckling modes. This entropy-based analysis enables the differentiation between symmetric and anti-symmetric buckling modes, which is particularly valuable when the critical buckling loads of sway and non-sway buckling modes are closely aligned or overlap.","PeriodicalId":39203,"journal":{"name":"International Journal of Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42529001","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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