The analysis of rail/wheel sliding friction heat is a very important research field. The numerical simulation is often adopted to calculate the friction heat, and experimental method is relatively few. In this paper, an experimental machine is designed to simulate the rail/wheel sliding contact. At the same time, a rail/wheel contact wear model and a friction heat transfer model are established. The characteristics of temperature on rail/wheel sliding contact are analyzed by experimental test and numerical calculation. The research results show that the temperature rise of wheel and rail is quick in the initial sliding contact stage, then gradually slows down. The temperature of wheel is higher than that of rail at the same depth from the contact surface. In the initial sliding stage, the wheel temperature rises faster than the rail temperature, which is related to the size of contact surface and the concentration degree of friction heat. Moreover, the results of this paper show that the temperature values of the rail/wheel obtained through experimental test and numerical calculation are in good agreement. The experimental and numerical calculation methods used in this article can be adopted to analyze the contact problems of other sliding friction pairs.
{"title":"An experimental measurement and numerical calculation method on friction temperature rise of sliding contact pairs - taking rail/wheel contact as an example","authors":"Yunpeng Wei, Yaping Wu, Zhidong Chen","doi":"10.21595/jme.2023.22974","DOIUrl":"https://doi.org/10.21595/jme.2023.22974","url":null,"abstract":"The analysis of rail/wheel sliding friction heat is a very important research field. The numerical simulation is often adopted to calculate the friction heat, and experimental method is relatively few. In this paper, an experimental machine is designed to simulate the rail/wheel sliding contact. At the same time, a rail/wheel contact wear model and a friction heat transfer model are established. The characteristics of temperature on rail/wheel sliding contact are analyzed by experimental test and numerical calculation. The research results show that the temperature rise of wheel and rail is quick in the initial sliding contact stage, then gradually slows down. The temperature of wheel is higher than that of rail at the same depth from the contact surface. In the initial sliding stage, the wheel temperature rises faster than the rail temperature, which is related to the size of contact surface and the concentration degree of friction heat. Moreover, the results of this paper show that the temperature values of the rail/wheel obtained through experimental test and numerical calculation are in good agreement. The experimental and numerical calculation methods used in this article can be adopted to analyze the contact problems of other sliding friction pairs.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49291373","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}
An adaptive denoising method based on 2D empirical mode decomposition (EMD) is proposed to improve the infrared image quality of inspection UNMANNED aerial vehicles (UAVs) and provide guarantee for improving the inspection level of distribution network. Through rapid adaptive two-dimensional empirical mode decomposition algorithm decomposition of a UAV collected for distribution network inspection original noise of infrared image, get more than the IMF component and the residual amount, a forecast noise dominated the IMF component parameters such as threshold value and the variance of noise, using the estimated parameters in combination with the optimal linear interpolation algorithm of noise threshold function of leading the IMF component implementation of threshold denoising. After the denoised IMF component is obtained, the denoised infrared image is obtained after reconstruction with the signal-dominated IMF component, and the adaptive denoising of the infrared image of the distribution network inspection UAV is realized. The experimental results show that the method in this paper can maintain the details of the image, improve the definition, significantly improve the visual effect, the overall denoising performance is stable and feasible, and ensure the quality inspection UAV to collect infrared images.
{"title":"An adaptive infrared image denoising method based on two-dimensional empirical mode decomposition for distribution network inspection UAV","authors":"Qigang Zhou, Lei Yang, Feng Liu, Songyu Li","doi":"10.21595/jme.2023.23010","DOIUrl":"https://doi.org/10.21595/jme.2023.23010","url":null,"abstract":"An adaptive denoising method based on 2D empirical mode decomposition (EMD) is proposed to improve the infrared image quality of inspection UNMANNED aerial vehicles (UAVs) and provide guarantee for improving the inspection level of distribution network. Through rapid adaptive two-dimensional empirical mode decomposition algorithm decomposition of a UAV collected for distribution network inspection original noise of infrared image, get more than the IMF component and the residual amount, a forecast noise dominated the IMF component parameters such as threshold value and the variance of noise, using the estimated parameters in combination with the optimal linear interpolation algorithm of noise threshold function of leading the IMF component implementation of threshold denoising. After the denoised IMF component is obtained, the denoised infrared image is obtained after reconstruction with the signal-dominated IMF component, and the adaptive denoising of the infrared image of the distribution network inspection UAV is realized. The experimental results show that the method in this paper can maintain the details of the image, improve the definition, significantly improve the visual effect, the overall denoising performance is stable and feasible, and ensure the quality inspection UAV to collect infrared images.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46020441","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 rail transit and civil aviation are the important components of the comprehensive transportation system. The development of the air-rail combined transport is an important effective way for China to become a country with strong transportation network. The transportation intersection form of railway under-passing airport transportation hub gradually becomes popular, thus the environmental vibration due to the under-passing railway cannot be ignored. In this paper, a large-scale integrated transportation hub construction project was taken as an example to analyze the transmission rule of environmental vibration due to the high-speed railway at the speed of 350 km/h under-passing airport in terms of the time domain and frequency domain by means of the on-site in-situ wheel-drop test. The research results show that the vertical vibration response of the ground surface along the normal direction of the railway is greater than those of the other two directions within 40 m from the centerline of the track. A vibration amplification zone appears within 5-40 m. The longitudinal vibration response of the ground surface is greater than those of the other two directions within 40-70 m. The local vibration amplification zones appear within 5-20 m and 30-60 m. The lateral vibration level of the ground surface along the normal direction of the railway increase gradually, but attenuates at the distance of 40 m and 10 m with the maximum attenuation rate of 0.67. The vertical vibration level amplifies at the distance of 60 m. The longitudinal vibration level attenuates at the distance of 20 m with the maximum attenuation rate of 0.3, but amplifies at the distance of 40 m with the maximum amplification rate of 1.8.
{"title":"In-situ experiment research on environmental vibration transmission characteristics of air-rail combined airport","authors":"Zaixin Wu, Feng Dai, Jizhong Yang","doi":"10.21595/jme.2023.23062","DOIUrl":"https://doi.org/10.21595/jme.2023.23062","url":null,"abstract":"The rail transit and civil aviation are the important components of the comprehensive transportation system. The development of the air-rail combined transport is an important effective way for China to become a country with strong transportation network. The transportation intersection form of railway under-passing airport transportation hub gradually becomes popular, thus the environmental vibration due to the under-passing railway cannot be ignored. In this paper, a large-scale integrated transportation hub construction project was taken as an example to analyze the transmission rule of environmental vibration due to the high-speed railway at the speed of 350 km/h under-passing airport in terms of the time domain and frequency domain by means of the on-site in-situ wheel-drop test. The research results show that the vertical vibration response of the ground surface along the normal direction of the railway is greater than those of the other two directions within 40 m from the centerline of the track. A vibration amplification zone appears within 5-40 m. The longitudinal vibration response of the ground surface is greater than those of the other two directions within 40-70 m. The local vibration amplification zones appear within 5-20 m and 30-60 m. The lateral vibration level of the ground surface along the normal direction of the railway increase gradually, but attenuates at the distance of 40 m and 10 m with the maximum attenuation rate of 0.67. The vertical vibration level amplifies at the distance of 60 m. The longitudinal vibration level attenuates at the distance of 20 m with the maximum attenuation rate of 0.3, but amplifies at the distance of 40 m with the maximum amplification rate of 1.8.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47887362","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. Ermolaev, B. Gordeev, S. Okhulkov, G. Panovko, A. Plekhov
The task of measuring of rotating shafts angular deformation by means of ultrasonic vibration meter is considered in the article. Measurement of vibration parameters of rotating objects is an urgent task in the technical diagnostics of electromechanical units, turbines, drilling rigs and metal-cutting machines subject to vibration disturbances. The measured vibration parameters of rotating shafts include their angular deformation and torques arising from torsional vibrations of shafting of machines in the stationary and mobile objects. Timely monitoring of the torsional vibrations of the shafting and other factors of vibration disturbances by the frequency of shaft beats makes it possible to identify defects at an early stage and eliminate breakdowns that threaten the life and safety of personnel. It was found out that the reflected acoustic signal phase measurement relative to the reference one incident onto the investigated shaft surface can be carried out with error at 0.6 % at velocities not more than 0.5 m/s. This article is intended for mechanical engineers involved in the development and operation of rotating machines of stationary and mobile objects.
{"title":"Measuring of rotating shafts angular deformation by means of ultrasonic vibration meter","authors":"A. Ermolaev, B. Gordeev, S. Okhulkov, G. Panovko, A. Plekhov","doi":"10.21595/jme.2022.22919","DOIUrl":"https://doi.org/10.21595/jme.2022.22919","url":null,"abstract":"The task of measuring of rotating shafts angular deformation by means of ultrasonic vibration meter is considered in the article. Measurement of vibration parameters of rotating objects is an urgent task in the technical diagnostics of electromechanical units, turbines, drilling rigs and metal-cutting machines subject to vibration disturbances. The measured vibration parameters of rotating shafts include their angular deformation and torques arising from torsional vibrations of shafting of machines in the stationary and mobile objects. Timely monitoring of the torsional vibrations of the shafting and other factors of vibration disturbances by the frequency of shaft beats makes it possible to identify defects at an early stage and eliminate breakdowns that threaten the life and safety of personnel. It was found out that the reflected acoustic signal phase measurement relative to the reference one incident onto the investigated shaft surface can be carried out with error at 0.6 % at velocities not more than 0.5 m/s. This article is intended for mechanical engineers involved in the development and operation of rotating machines of stationary and mobile objects.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42825686","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}
Ruslans Muhitovs, M. Mezitis, G. Strautmanis, Vladimirs Iriskovs
The article discusses the possibility of applying the results of regression analysis [1], fuzzy logic modelling and adaptive systems as such for use in heating control circuits of railway turnouts in order to reduce energy consumption, reduce current surges during on/off switching, and extend the life of heating elements. Based on various researches [2-4] some new solutions are proposed to fulfil shortages of current solutions. As a proposed solution to the described problem, an experimental point electric heating adaptive control system is proposed and described. Experiment of controlling point electric heating system using pulse-width modulation driven by values of regression analysis and fuzzy logic elements. Adaptive methods allowed to dismiss contact temperature sensors, which is associated with a decrease in the reliability of the system, but this fact is prevented by the use of such control methods that can indirectly determine the required rail heating temperature. Conclusions show that the approach of introducing adaptive methods like pulse-width modulation allows to control point electric heating in more efficient way – using program code, control system will adjust heating by adjusting time intervals when the heating is turned on and off.
{"title":"Indirect measurements in the intelligent heating control system for the turnout using adaptive systems","authors":"Ruslans Muhitovs, M. Mezitis, G. Strautmanis, Vladimirs Iriskovs","doi":"10.21595/jme.2022.23028","DOIUrl":"https://doi.org/10.21595/jme.2022.23028","url":null,"abstract":"The article discusses the possibility of applying the results of regression analysis [1], fuzzy logic modelling and adaptive systems as such for use in heating control circuits of railway turnouts in order to reduce energy consumption, reduce current surges during on/off switching, and extend the life of heating elements. Based on various researches [2-4] some new solutions are proposed to fulfil shortages of current solutions. As a proposed solution to the described problem, an experimental point electric heating adaptive control system is proposed and described. Experiment of controlling point electric heating system using pulse-width modulation driven by values of regression analysis and fuzzy logic elements. Adaptive methods allowed to dismiss contact temperature sensors, which is associated with a decrease in the reliability of the system, but this fact is prevented by the use of such control methods that can indirectly determine the required rail heating temperature. Conclusions show that the approach of introducing adaptive methods like pulse-width modulation allows to control point electric heating in more efficient way – using program code, control system will adjust heating by adjusting time intervals when the heating is turned on and off.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48085356","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}
Wenhui Zhang, Zhi Wen, Yangfan Ye, Jinmiao Shen, X. Ye
Aiming at the complex electromechanical coupling effect at the joints of RP (rotating parallel) flexible robot, the electromechanical coupling dynamics and vibration response characteristics driven by AC servo motor, as well as the dynamic starting characteristics of the motor are studied. The physical model including electromagnetic and mechanical system coupling is established, and the dynamic model of the whole system is derived based on the overall electromechanical coupling effect and Lagrange Maxwell equation. With the help of Matlab/Simulink, a virtual simulation platform is built to analyze the output speed characteristics of the motor drive end and the motion of the moving base. Finally, through the joint simulation of Matlab/Simulink dynamic simulation model and Adams/controls virtual prototype model, the vibration characteristics of flexible manipulator under electromechanical coupling are obtained. The simulation results show that the electromechanical coupling effect of the motor drive end has a significant impact on the dynamic characteristics of the flexible manipulator. The conclusions obtained are of great value for improving the chiral energy of flexible machinery.
{"title":"Dynamic and vibration characteristics of flexible robot manipulator under complex electromechanical coupling","authors":"Wenhui Zhang, Zhi Wen, Yangfan Ye, Jinmiao Shen, X. Ye","doi":"10.21595/jme.2022.22836","DOIUrl":"https://doi.org/10.21595/jme.2022.22836","url":null,"abstract":"Aiming at the complex electromechanical coupling effect at the joints of RP (rotating parallel) flexible robot, the electromechanical coupling dynamics and vibration response characteristics driven by AC servo motor, as well as the dynamic starting characteristics of the motor are studied. The physical model including electromagnetic and mechanical system coupling is established, and the dynamic model of the whole system is derived based on the overall electromechanical coupling effect and Lagrange Maxwell equation. With the help of Matlab/Simulink, a virtual simulation platform is built to analyze the output speed characteristics of the motor drive end and the motion of the moving base. Finally, through the joint simulation of Matlab/Simulink dynamic simulation model and Adams/controls virtual prototype model, the vibration characteristics of flexible manipulator under electromechanical coupling are obtained. The simulation results show that the electromechanical coupling effect of the motor drive end has a significant impact on the dynamic characteristics of the flexible manipulator. The conclusions obtained are of great value for improving the chiral energy of flexible machinery.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46690735","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}
Kai Dong, Qingbin Shen, Chengyi Wang, Yanwu Dong, Z. Lu
When the conductor is covered with ice on a non-circular section, and there is low-frequency, large-amplitude motion under wind excitation, it is usually called the transmission line galloping phenomenon. Due to the large amplitude, the galloping of the transmission line will lead to line fatigue, increase in tension, damage to hardware, or toppling of towers. In addition, it will also lead to flashover, tripping, and other transmission accidents caused by the short phase distance, which is not conducive to the safe operation of power grids. In order to improve the safety of power grid operation, this paper designed an online monitoring and early warning system for transmission line galloping on the basis of multi-source data and verified the system through implementation. It was found that the safety factor was 1.568, which determines its early warning level and affirms the feasibility of this study. This research has a positive role in improving the safe operation of the power grid.
{"title":"Research on online monitoring and early warning system of transmission line galloping based on multi-source data","authors":"Kai Dong, Qingbin Shen, Chengyi Wang, Yanwu Dong, Z. Lu","doi":"10.21595/jme.2022.22818","DOIUrl":"https://doi.org/10.21595/jme.2022.22818","url":null,"abstract":"When the conductor is covered with ice on a non-circular section, and there is low-frequency, large-amplitude motion under wind excitation, it is usually called the transmission line galloping phenomenon. Due to the large amplitude, the galloping of the transmission line will lead to line fatigue, increase in tension, damage to hardware, or toppling of towers. In addition, it will also lead to flashover, tripping, and other transmission accidents caused by the short phase distance, which is not conducive to the safe operation of power grids. In order to improve the safety of power grid operation, this paper designed an online monitoring and early warning system for transmission line galloping on the basis of multi-source data and verified the system through implementation. It was found that the safety factor was 1.568, which determines its early warning level and affirms the feasibility of this study. This research has a positive role in improving the safe operation of the power grid.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48814723","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}
Hao Zhang, Huaxin Zhu, Defeng Zhang, Jie Wang, C. Zhang, D. Novák
This study aims to investigate the barrier effect of front wall-soil-barrier interactions in barrier sheet pile wharf structures. Berth 32 of the Jingtang Port was taken as the prototype structure, and the prototype observation experiment, centrifugal model test, and numerical calculation analysis were performed to study the influence of the length of the barrier pile, the spacing D between wall piles, and the net spacing L of the barrier pile on the barrier effect. The results show that, to maximize the barrier effect, the ratio N of the pile length of the full barrier pile to the depth of the front wall should be between 1.0 and 1.1. To maximize the barrier effect, the top elevation of the semi-barrier pile should not be excessively low. When the bottom elevation is fixed, the ratio of the length of the semi-barrier pile to the depth of the front wall is approximately N= 0.7. The change in the wall pile spacing D has a considerable impact on the barrier effect. Moreover, D has a logarithmic relationship to the horizontal displacement of the front wall. When D exceeds 3 m, the change in the barrier effect can be ignored. The part of the earth pressure shared by the sea and land sides of the barrier pile to the soil between the barrier pile and the barrier pile has a logarithmic relationship to the net spacing L of the barrier pile. The smaller the L, the better the barrier effect. When L exceeds 2 m, the earth pressure shared by the two parts tends to be average, and the barrier effect can be ignored.
{"title":"Influence of barrier effect on barrier sheet pile wharf","authors":"Hao Zhang, Huaxin Zhu, Defeng Zhang, Jie Wang, C. Zhang, D. Novák","doi":"10.21595/jme.2022.22921","DOIUrl":"https://doi.org/10.21595/jme.2022.22921","url":null,"abstract":"This study aims to investigate the barrier effect of front wall-soil-barrier interactions in barrier sheet pile wharf structures. Berth 32 of the Jingtang Port was taken as the prototype structure, and the prototype observation experiment, centrifugal model test, and numerical calculation analysis were performed to study the influence of the length of the barrier pile, the spacing D between wall piles, and the net spacing L of the barrier pile on the barrier effect. The results show that, to maximize the barrier effect, the ratio N of the pile length of the full barrier pile to the depth of the front wall should be between 1.0 and 1.1. To maximize the barrier effect, the top elevation of the semi-barrier pile should not be excessively low. When the bottom elevation is fixed, the ratio of the length of the semi-barrier pile to the depth of the front wall is approximately N= 0.7. The change in the wall pile spacing D has a considerable impact on the barrier effect. Moreover, D has a logarithmic relationship to the horizontal displacement of the front wall. When D exceeds 3 m, the change in the barrier effect can be ignored. The part of the earth pressure shared by the sea and land sides of the barrier pile to the soil between the barrier pile and the barrier pile has a logarithmic relationship to the net spacing L of the barrier pile. The smaller the L, the better the barrier effect. When L exceeds 2 m, the earth pressure shared by the two parts tends to be average, and the barrier effect can be ignored.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47634693","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}
Aiming at improving the method of underwater target recognition, this paper proposes a method to estimate the micro-Doppler spectrum parameters of propeller by using inverse Radon transform, so as to obtain the characteristic parameters of propeller. This paper firstly analyzes the basic concepts of micro-Doppler and inverse Radon transform, then defines the algorithm steps of inverse Radon transform for propeller parameter estimation and carries out simulation. The simulation results show that this method can effectively estimate the propeller rotational speed, blade number, blade length and initial spatial position.
{"title":"Parameter estimation of underwater propeller based on inverse Radon transform","authors":"Tang Bo, Zhan Linsen, Tan Siwei","doi":"10.21595/jme.2022.22781","DOIUrl":"https://doi.org/10.21595/jme.2022.22781","url":null,"abstract":"Aiming at improving the method of underwater target recognition, this paper proposes a method to estimate the micro-Doppler spectrum parameters of propeller by using inverse Radon transform, so as to obtain the characteristic parameters of propeller. This paper firstly analyzes the basic concepts of micro-Doppler and inverse Radon transform, then defines the algorithm steps of inverse Radon transform for propeller parameter estimation and carries out simulation. The simulation results show that this method can effectively estimate the propeller rotational speed, blade number, blade length and initial spatial position.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46828129","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}
N. Abbas, M. Yousaf, M. Akbar, Pan Huali, M. Usman Yousaf, Ou Guoqiang
The construction of a structure is prohibitively expensive due to high material and labour expenses. Still, the production of cement, which is the most widely used binding substance in construction, results in the emission of a large amount of CO2 into the atmosphere. It has only recently been discovered that Pakistan is short of approximately 9 million residential constructions. Thus, there is a great need for cost-effective and energy-efficient masonry construction because of economic and environmental concerns. Rat-trap masonry bond creates a cavity in the wall, which serves as both thermal insulation and a cost-saving measure. Because of the inherent property of rat-trap masonry bond, a cavity is formed in the wall, which not only serves as thermal insulation for the interior but is also cost-effective It has been observed that approximately 26.11 % of the total construction cost, comprising of labor and material, can be curtailed by adopting the rat-trap bonding technique. Rat-trap bond construction is recognized as a greener and more sustainable alternative to conventional brick bonds. A comparative study of the structural behavior of the rat-trap and conventionally used English bond has been conducted. 72 prisms of rat-trap bond and English bond from three sources of bricks were tested under compression load at the ages of 28 and 56 days. The same number of prisms were tested under diagonal tension load at both ages. 18 triplet prisms from all sources of bricks were tested for shear bond strength without lateral load, whereas 5 triplet prisms from every brick source were tested with a set of lateral pre-compression loading of 29 psi, 87 psi, and 145 psi. The results show that the rat-trap bond has much higher compressive and shear strengths than the English bond.
{"title":"To experimental study of performance evaluation of masonry brick bond in shear and compression in comparison","authors":"N. Abbas, M. Yousaf, M. Akbar, Pan Huali, M. Usman Yousaf, Ou Guoqiang","doi":"10.21595/jme.2022.22559","DOIUrl":"https://doi.org/10.21595/jme.2022.22559","url":null,"abstract":"The construction of a structure is prohibitively expensive due to high material and labour expenses. Still, the production of cement, which is the most widely used binding substance in construction, results in the emission of a large amount of CO2 into the atmosphere. It has only recently been discovered that Pakistan is short of approximately 9 million residential constructions. Thus, there is a great need for cost-effective and energy-efficient masonry construction because of economic and environmental concerns. Rat-trap masonry bond creates a cavity in the wall, which serves as both thermal insulation and a cost-saving measure. Because of the inherent property of rat-trap masonry bond, a cavity is formed in the wall, which not only serves as thermal insulation for the interior but is also cost-effective It has been observed that approximately 26.11 % of the total construction cost, comprising of labor and material, can be curtailed by adopting the rat-trap bonding technique. Rat-trap bond construction is recognized as a greener and more sustainable alternative to conventional brick bonds. A comparative study of the structural behavior of the rat-trap and conventionally used English bond has been conducted. 72 prisms of rat-trap bond and English bond from three sources of bricks were tested under compression load at the ages of 28 and 56 days. The same number of prisms were tested under diagonal tension load at both ages. 18 triplet prisms from all sources of bricks were tested for shear bond strength without lateral load, whereas 5 triplet prisms from every brick source were tested with a set of lateral pre-compression loading of 29 psi, 87 psi, and 145 psi. The results show that the rat-trap bond has much higher compressive and shear strengths than the English bond.","PeriodicalId":42196,"journal":{"name":"Journal of Measurements in Engineering","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43544235","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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