: With the development of fiber-reinforced cement composites, the diversity and complexity of application scenarios require enhanced strength and ductility and tough materials in practical engineering. To explore the effects of different water-binder ratios and fiber contents on the fluidity, bending resistance, tensile properties, fracture toughness, and fracture behavior of polyvinyl alcohol (PVA) fiber cement composites, several groups of high ductility test blocks (PVA-engineering cementitious composites (ECC)) with different mixing ratios were designed in this study. Based on the expansion degree, the mechanical experimental data, and the electron microscopy scanning image results, K -value analysis was performed on the strain hardening strength criterion. The effect of the water–binder ratio and the fiber dosing on the PVA-ECC material was determined. Results show that the greater the water-binder ratio is, the better the fluidity of the ECC matrix is. In the same cement system and at the same water-binder ratio, the fluidity of the ECC paste gradually deteriorates with the increase of the fiber content. The water-binder ratio significantly affects the flexural tensile strength of the composite. The flexural and tensile strengths of the PVA-ECC gradually increase as the water-binder ratio decreases, but the ductility gradually decreases. The water-binder ratio of the substrate directly influences the damage behavior of the fibers within the substrate. With the gradual increase of the water-binder ratio, the fiber at the crack interface gradually changes from pull-out morphology to fracture morphology. The strain capacity and the multi-crack cracking performance decrease. To achieve improved working performance in the actual project, the matrix water-binder ratio should be controlled at approximately 0.45, and the PVA fiber dose of 1.7% is optimal. This study can provide a good reference for
{"title":"Effect of Different Water-Binder Ratios and Fiber Contents on the Fluidity and Mechanical Properties of PVA-ECC Materials","authors":"Qin Xin, Ruyu Gao, Peng-Cheng Shao, LV Wenbo, Hao Wei","doi":"10.17559/tv-20230426000576","DOIUrl":"https://doi.org/10.17559/tv-20230426000576","url":null,"abstract":": With the development of fiber-reinforced cement composites, the diversity and complexity of application scenarios require enhanced strength and ductility and tough materials in practical engineering. To explore the effects of different water-binder ratios and fiber contents on the fluidity, bending resistance, tensile properties, fracture toughness, and fracture behavior of polyvinyl alcohol (PVA) fiber cement composites, several groups of high ductility test blocks (PVA-engineering cementitious composites (ECC)) with different mixing ratios were designed in this study. Based on the expansion degree, the mechanical experimental data, and the electron microscopy scanning image results, K -value analysis was performed on the strain hardening strength criterion. The effect of the water–binder ratio and the fiber dosing on the PVA-ECC material was determined. Results show that the greater the water-binder ratio is, the better the fluidity of the ECC matrix is. In the same cement system and at the same water-binder ratio, the fluidity of the ECC paste gradually deteriorates with the increase of the fiber content. The water-binder ratio significantly affects the flexural tensile strength of the composite. The flexural and tensile strengths of the PVA-ECC gradually increase as the water-binder ratio decreases, but the ductility gradually decreases. The water-binder ratio of the substrate directly influences the damage behavior of the fibers within the substrate. With the gradual increase of the water-binder ratio, the fiber at the crack interface gradually changes from pull-out morphology to fracture morphology. The strain capacity and the multi-crack cracking performance decrease. To achieve improved working performance in the actual project, the matrix water-binder ratio should be controlled at approximately 0.45, and the PVA fiber dose of 1.7% is optimal. This study can provide a good reference for","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"10 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79137751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: This paper proposed a wedge concrete fixed pier device based on self-locking to solve the problems existing in the fixed pier of water supply pipeline in utility tunnels. The system converted the horizontal thrust, originally applied to the weld seam in the pipeline, into oblique downward pressure by bending the pipeline upward. When the pipeline was bent upward at an angle equal to twice the horizontal angle of the wedge concrete fixed pier, then the fixed pier achieved the variable pressure-bearing effect in the horizontal direction through the self-locking between the concrete pier and the bottom plate of the utility tunnels. In addition, this avoided the damage to the fixed pier device, caused by the instantaneous pipeline internal pressure exceeding the maximum bearing thrust of the weld seam. The wedge fixed pier could be poured twice when the pipeline entered the utility tunnels, saving the rework cost of pouring the concrete again due to the changes of the design positioning of the water supply pipeline. As long as the area of the built-in steel fittings in the wedge concrete exceeded a certain range, the wedge concrete pier would not be crushed.
{"title":"Structural Design of Pressure Pipeline Wedge-Shaped Concrete Piers","authors":"Yanfang Li, Yonghua Wang, Jingyao Cai, Chao Ren, Bo Zhang, Bing Zhang","doi":"10.17559/tv-20230308000423","DOIUrl":"https://doi.org/10.17559/tv-20230308000423","url":null,"abstract":": This paper proposed a wedge concrete fixed pier device based on self-locking to solve the problems existing in the fixed pier of water supply pipeline in utility tunnels. The system converted the horizontal thrust, originally applied to the weld seam in the pipeline, into oblique downward pressure by bending the pipeline upward. When the pipeline was bent upward at an angle equal to twice the horizontal angle of the wedge concrete fixed pier, then the fixed pier achieved the variable pressure-bearing effect in the horizontal direction through the self-locking between the concrete pier and the bottom plate of the utility tunnels. In addition, this avoided the damage to the fixed pier device, caused by the instantaneous pipeline internal pressure exceeding the maximum bearing thrust of the weld seam. The wedge fixed pier could be poured twice when the pipeline entered the utility tunnels, saving the rework cost of pouring the concrete again due to the changes of the design positioning of the water supply pipeline. As long as the area of the built-in steel fittings in the wedge concrete exceeded a certain range, the wedge concrete pier would not be crushed.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"137 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76496074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-15DOI: 10.17559/tv-20230111000218
Chengji Mi, Yang Hai, Fazhan Wu, Liang Luo, Zejun Chen, Youhua Fan, Di Kang
. In order to improve the dynamic characteristics of the slider pallet in the camellia fruit picking machine under the traditional empirical design and to lighten the weight, a fuzzy multi-objective topology optimization design method was proposed. In this paper, a static and dynamic topology optimization mathematical model was constructed by the compromise programming method, and the weight coefficients of each sub-objective were dynamically assigned by the fuzzy satisfaction variable weight coefficient method, and then the fuzzy multi-objective topology optimization design of the slider pallet for bending condition, bending-torsional complex condition, inertia condition and the first three orders of dynamic frequency was performed. The optimization results showed that the weight of the optimized slider pallet was reduced by 19.4%, and the first-order modal frequency was increased by 5.0%, second order modal frequency increased by 6.6%, third order modal frequency increased by 8.2%; the maximum deformation and maximum stress were increased, but still met the design requirements.
{"title":"Fuzzy Multi-Objectives Topology Optimization of Slider Pallet in the Picking Machine of Camellia Fruit","authors":"Chengji Mi, Yang Hai, Fazhan Wu, Liang Luo, Zejun Chen, Youhua Fan, Di Kang","doi":"10.17559/tv-20230111000218","DOIUrl":"https://doi.org/10.17559/tv-20230111000218","url":null,"abstract":". In order to improve the dynamic characteristics of the slider pallet in the camellia fruit picking machine under the traditional empirical design and to lighten the weight, a fuzzy multi-objective topology optimization design method was proposed. In this paper, a static and dynamic topology optimization mathematical model was constructed by the compromise programming method, and the weight coefficients of each sub-objective were dynamically assigned by the fuzzy satisfaction variable weight coefficient method, and then the fuzzy multi-objective topology optimization design of the slider pallet for bending condition, bending-torsional complex condition, inertia condition and the first three orders of dynamic frequency was performed. The optimization results showed that the weight of the optimized slider pallet was reduced by 19.4%, and the first-order modal frequency was increased by 5.0%, second order modal frequency increased by 6.6%, third order modal frequency increased by 8.2%; the maximum deformation and maximum stress were increased, but still met the design requirements.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"44 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85758282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-15DOI: 10.17559/tv-20230210000344
Roja Ganesan, Maheswara Venkatesh, Jayasankar Thangaiyan, Lecturer Ms. Roja GANESAN, Dr. Maheswara Venkatesh Panchavarnam
: A dual-band antenna is used for several wireless networks like ISM, WLAN, WiMAX, and WiFi. The antenna's uppermost element is a monopole shape with a rectangular protrusion. Antennas are created in CST. Using a 19-millimetre-wide by 31-millimetre-long FR4 substrate, the antenna is created in a design environment. Due to the SRR printing in the ground and the antenna's defective ground structure, the antenna is able to achieve dual resonance. A split ring resonator printed at the base also helps achieve a second resonance. With the help of a parameter analysis, we can pick the optimal proportions for the design. The antenna resonates at both 2.3 and 5.8 GHz. We construct and test the antenna. The results obtained through simulation are equivalent to those obtained from measurements in terms of s11, gain, and directivity, as well as E-plane and H-plane patterns. Because of its compact size, consistent radiation pattern, dual-band use, and excellent impedance matching and bandwidth, the suggested antenna is an excellent choice for use in ISM networks and other wireless applications.
{"title":"Split Ring Resonator Inspired Dual-Band Monopole Antenna for ISM, WLAN, WIFI, and WiMAX Application","authors":"Roja Ganesan, Maheswara Venkatesh, Jayasankar Thangaiyan, Lecturer Ms. Roja GANESAN, Dr. Maheswara Venkatesh Panchavarnam","doi":"10.17559/tv-20230210000344","DOIUrl":"https://doi.org/10.17559/tv-20230210000344","url":null,"abstract":": A dual-band antenna is used for several wireless networks like ISM, WLAN, WiMAX, and WiFi. The antenna's uppermost element is a monopole shape with a rectangular protrusion. Antennas are created in CST. Using a 19-millimetre-wide by 31-millimetre-long FR4 substrate, the antenna is created in a design environment. Due to the SRR printing in the ground and the antenna's defective ground structure, the antenna is able to achieve dual resonance. A split ring resonator printed at the base also helps achieve a second resonance. With the help of a parameter analysis, we can pick the optimal proportions for the design. The antenna resonates at both 2.3 and 5.8 GHz. We construct and test the antenna. The results obtained through simulation are equivalent to those obtained from measurements in terms of s11, gain, and directivity, as well as E-plane and H-plane patterns. Because of its compact size, consistent radiation pattern, dual-band use, and excellent impedance matching and bandwidth, the suggested antenna is an excellent choice for use in ISM networks and other wireless applications.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"22 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81326529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-15DOI: 10.17559/tv-20230323000469
{"title":"3D Reconstruction of Optical Building Images Based on Improved 3D-R2N2 Algorithm","authors":"","doi":"10.17559/tv-20230323000469","DOIUrl":"https://doi.org/10.17559/tv-20230323000469","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"3 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80065627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-15DOI: 10.17559/tv-20230306000407
Qiheng Wang, Associate Professor Yang LI, Doctor Zixuan WANG
: Hyperbolic paraboloid is a kind of ruled space surface with beautiful shape. It is often used in architectural design and can achieve a free and flexible appearance effect. Due to the complexity of curved surfaces, many architects do not know how to navigate them. The main purpose of this article is to explore how to use hyperbolic paraboloids in architectural design. Firstly, the formation principle of hyperbolic paraboloid is analyzed from a mathematical perspective. Then, through investigating examples, it expounds its application in architectural design. Hyperbolic paraboloids are mainly used in building roofs, especially in large span buildings. There are three uses of hyperbolic paraboloids in roofs, corresponding to three different architectural shapes.The first is to cut a hyperbolic paraboloid vertically with four planes, and the contour projection is a rectangle or parallelogram. The second is to cut the hyperbolic paraboloid vertically and horizontally with four planes, and the contour projection is a curved quadrilateral. The third is to cut hyperbolic paraboloid with elliptic surface, and the contour projection is an ellipse. Finally, the conclusion is drawn on how to flexibly use hyperbolic paraboloids in architectural design, and what are the advantages and disadvantages of hyperbolic paraboloids, which has important reference value for architects to carry out related designs.
{"title":"Application of Hyperbolic Paraboloid in Architectural Design","authors":"Qiheng Wang, Associate Professor Yang LI, Doctor Zixuan WANG","doi":"10.17559/tv-20230306000407","DOIUrl":"https://doi.org/10.17559/tv-20230306000407","url":null,"abstract":": Hyperbolic paraboloid is a kind of ruled space surface with beautiful shape. It is often used in architectural design and can achieve a free and flexible appearance effect. Due to the complexity of curved surfaces, many architects do not know how to navigate them. The main purpose of this article is to explore how to use hyperbolic paraboloids in architectural design. Firstly, the formation principle of hyperbolic paraboloid is analyzed from a mathematical perspective. Then, through investigating examples, it expounds its application in architectural design. Hyperbolic paraboloids are mainly used in building roofs, especially in large span buildings. There are three uses of hyperbolic paraboloids in roofs, corresponding to three different architectural shapes.The first is to cut a hyperbolic paraboloid vertically with four planes, and the contour projection is a rectangle or parallelogram. The second is to cut the hyperbolic paraboloid vertically and horizontally with four planes, and the contour projection is a curved quadrilateral. The third is to cut hyperbolic paraboloid with elliptic surface, and the contour projection is an ellipse. Finally, the conclusion is drawn on how to flexibly use hyperbolic paraboloids in architectural design, and what are the advantages and disadvantages of hyperbolic paraboloids, which has important reference value for architects to carry out related designs.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"119 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82451577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-15DOI: 10.17559/tv-20230409000516
{"title":"Study on the Evolution Mechanism of Lane Change Decision in Urban Expressway Diversion Area","authors":"","doi":"10.17559/tv-20230409000516","DOIUrl":"https://doi.org/10.17559/tv-20230409000516","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"96 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78770005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-15DOI: 10.17559/tv-20221108150435
: In the present study, different solution methods are discussed in order to control the quadrotor with the most optimal PID parameters for the determined purposes. One of these methods is to make use of meta-heuristic algorithms in control systems. There are some limitations of using a PID controller as a classical construct. However, it is thought that more successful results will be obtained by optimizing its parameters through meta-heuristic algorithms. Initially, the mathematical model of the vehicle was created in MATLAB/Simulink. Then, genetic algorithms (GA), artificial bee colony (ABC), particle swarm optimization (PSO) and firefly algorithms (FA) were determined respectively as optimization methods. And these optimization methods used to determine the PID control parameters are applied to the developed mathematical model in the MATLAB/Simulink environment. In addition, the performances of the optimization methods are evaluated according to the comparison criteria. As a result of the comparison carried out according to ITAE (Integral Time Absolute Error) fitness criteria, ABC (1.2% - 4.4%) in terms of altitude, FA (4% - 13%) in terms of roll angle, GA (13% - %21) in terms of pitch angle, and PSO (4% - %15) in terms of yaw angle has been more successful than other methods.
{"title":"Comparison of Metaheuristic Optimization Algorithms for Quadrotor PID Controllers","authors":"","doi":"10.17559/tv-20221108150435","DOIUrl":"https://doi.org/10.17559/tv-20221108150435","url":null,"abstract":": In the present study, different solution methods are discussed in order to control the quadrotor with the most optimal PID parameters for the determined purposes. One of these methods is to make use of meta-heuristic algorithms in control systems. There are some limitations of using a PID controller as a classical construct. However, it is thought that more successful results will be obtained by optimizing its parameters through meta-heuristic algorithms. Initially, the mathematical model of the vehicle was created in MATLAB/Simulink. Then, genetic algorithms (GA), artificial bee colony (ABC), particle swarm optimization (PSO) and firefly algorithms (FA) were determined respectively as optimization methods. And these optimization methods used to determine the PID control parameters are applied to the developed mathematical model in the MATLAB/Simulink environment. In addition, the performances of the optimization methods are evaluated according to the comparison criteria. As a result of the comparison carried out according to ITAE (Integral Time Absolute Error) fitness criteria, ABC (1.2% - 4.4%) in terms of altitude, FA (4% - 13%) in terms of roll angle, GA (13% - %21) in terms of pitch angle, and PSO (4% - %15) in terms of yaw angle has been more successful than other methods.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"18 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78670421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-15DOI: 10.17559/tv-20221218093637
{"title":"Research on Safety Investment Decision Evaluation and Optimization of Network Booking Taxi Platform Enterprise based on Subjective-Objective Assessment Method","authors":"","doi":"10.17559/tv-20221218093637","DOIUrl":"https://doi.org/10.17559/tv-20221218093637","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":"68 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84181825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：