Acta Polytechnica最新文献_第6页

Performance assessment of steel truss railway bridge with curved track 曲线轨道特拉斯铁路钢桥的性能评价

IF 0.8

Acta Polytechnica Pub Date : 2022-10-31 DOI: 10.14311/ap.2022.62.0558

M. Venglár, K. Lamperová, M. Sokol

{"title":"Performance assessment of steel truss railway bridge with curved track","authors":"M. Venglár, K. Lamperová, M. Sokol","doi":"10.14311/ap.2022.62.0558","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0558","url":null,"abstract":"Non-destructive Structural Health Monitoring techniques can be incorporated into bridge integrity management by assessing structural conditions. This paper describes a performance assessment of a steel truss railway bridge in Bratislava using vibration-based techniques as a further part of maintenance in addition to standard visual inspections. To obtain the necessary data, a multipurpose measuring system was used. Various types of data were measured, e.g. accelerations, strains, and displacements. The advantage of the multipurpose measuring system was that the traffic over the bridge was not restricted, even though the bridge carries only a single curved track. Two test campaigns were conducted to assess the performance of the bridge. One campaign was devoted to measuring ambient vibrations in order to perform the operational modal analysis, and the second was carried out to measure strains and displacements during a train passage. The results show a successful system identification of the structure using ambient vibrations; and a finite element model was verified and validated by a comparison of strains and displacements, as well as by modal parameters. According to the results obtained, the structural health of the investigated bridge was satisfactory.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47960547","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}

引用次数: 2

Reduction of pavement thickness using a subgrade layer treated by different techniques 采用不同技术处理的路基层降低路面厚度

IF 0.8

Acta Polytechnica Pub Date : 2022-10-31 DOI: 10.14311/ap.2022.62.0567

R. Zehawi, Y. A. Kareem, Emad Y. Khudhair

{"title":"Reduction of pavement thickness using a subgrade layer treated by different techniques","authors":"R. Zehawi, Y. A. Kareem, Emad Y. Khudhair","doi":"10.14311/ap.2022.62.0567","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0567","url":null,"abstract":"A range of stabilisers for poor quality subgrade soils have been developed to promote road constructions. Many of them are becoming more popular depending on their effectiveness. The purpose behind this research is to identify the relative efficacy of many physical and chemical stabilisation techniques for enhancing the properties of three types of local Iraqi subgrade soils. The comparison of the samples is based on the CBR tests. The AASHTO (1993) flexible pavement design was used to compute the pavement thickness requirements. The soil samples A, B and C have a natural CBR values of 3.8, 3.9 and 4, respectively, on which the physical stabilisers of Powdered rock (PR), grained recycled concrete (GRC), and recycled crumb rubber grains (CR) were employed, while Quicklime (QL) and activated fly ash (AFA) were both utilised as chemical stabilisers. The stabilisation with 15 % of AFA proved to be the most applicable method for soil types A and B for reducing the pavement thickness requirements by 51 % and 32 %, respectively, with a reasonable financial feasibility for both. The same feasibility is proven when stabilising soil type C with 15 % of GRC, which reduces the pavementthickness by 25.7 %.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45042877","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}

引用次数: 0

Concrete lintels reinforced with steel fibres oriented by a magnetic field 用磁场定向的钢纤维加固的混凝土门楣

IF 0.8

Acta Polytechnica Pub Date : 2022-10-31 DOI: 10.14311/ap.2022.62.0531

Kristýna Carrera, Karel Künzel, Petr Konrád, R. Sovják, V. Papež, M. Mára, J. Fornůsek, Přemysl Kheml

引用次数: 0

Extra control coefficient additive ECCA-PID for control optimization of electrical and mechanic system 附加控制系数加性ECCA-PID用于机电系统的控制优化

IF 0.8

Acta Polytechnica Pub Date : 2022-10-31 DOI: 10.14311/ap.2022.62.0522

Erol Can

引用次数: 0

Disinfection performance of an ultraviolet lamp: a CFD investigation 紫外线灯的消毒性能:CFD研究

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0418

C. Bui, N. Phan, Ngo Quoc Huy Tran, L. Doan, Quang Truong Vo, D. C. Tran, Thi Thanh Vi Nguyen, Duc Long Nguyen, Van Sanh Huynh, Tran Anh Ngoc Ho

{"title":"Disinfection performance of an ultraviolet lamp: a CFD investigation","authors":"C. Bui, N. Phan, Ngo Quoc Huy Tran, L. Doan, Quang Truong Vo, D. C. Tran, Thi Thanh Vi Nguyen, Duc Long Nguyen, Van Sanh Huynh, Tran Anh Ngoc Ho","doi":"10.14311/ap.2022.62.0418","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0418","url":null,"abstract":"Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41353145","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}

引用次数: 1

Performance of a hydromagnetic squeeze film on a rough circular step bearing: a comparision of different porous structures 粗糙圆形阶梯轴承上磁挤压膜的性能:不同多孔结构的比较

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0409

J. V. Adeshara, H. Patel, G. Deheri, R. Patel

{"title":"Performance of a hydromagnetic squeeze film on a rough circular step bearing: a comparision of different porous structures","authors":"J. V. Adeshara, H. Patel, G. Deheri, R. Patel","doi":"10.14311/ap.2022.62.0409","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0409","url":null,"abstract":"This investigation deals with a comparative analysis of the impact of spongy structure based on the model of Kozeny-Carman and Irmay on a hydromagnetic squeeze film in a rough circular step bearing. Christensen and Tonder’s stochastic averaging process has been utilized to determine the role of an arbitrary transverse surface irregularity. The distribution of the pressure in the bearing is obtained by solving the concerned generalised stochastically averaged equation of Reynolds’ with appropriate boundary conditions. The outcomes show that increasing values of magnetization results in an augmented load. The impact of the surface irregularity (transverse) has been found to be adverse. In addition, the negative effect of the surface irregularity and porosity can be minimised by the positive impact of magnetization, at least in the case of the globular sphere model of Kozeny-Carman. Furthermore, the lower strength of the magnetic field results in an approximately similar performance for both these models. This study offers the possibility that the Kozeny-Carman model could be deployed in comparison with Irmay’s model.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44816793","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}

引用次数: 0

A comparative study of ferrofluid lubrication on double-layer porous squeeze curved annular plates with slip velocity 具有滑移速度的双层多孔挤压弯曲环板铁磁流体润滑的对比研究

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0488

Niru C. Patel, J. Patel, G. Deheri

{"title":"A comparative study of ferrofluid lubrication on double-layer porous squeeze curved annular plates with slip velocity","authors":"Niru C. Patel, J. Patel, G. Deheri","doi":"10.14311/ap.2022.62.0488","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0488","url":null,"abstract":"This article makes an effort to present a comparative study on the performance of a Shliomis model-based ferrofluid (FF) lubrication of a porous squeeze film in curved annular plates taking slip velocity into account. The modified Darcy’s law has been adopted to find the impact of the doublelayered porosity, while the slip velocity effect has been calculated according to Beavers and Joseph’s slip conditions. The modified Reynolds equation for the double-layered bearing system is solved to compute a dimensionless pressure profile and load-bearing capacity (LBC). The graphical results of the study reveal that the LBC increases in the case of magnetization, volume concentration and upper plate’s curvature parameter while it decreases with other parameters for both the film thickness profile. A comparative study suggests that the exponential film thickness profile is more suitable to enhance LBC for the annular plates lubricated by ferrofluid, including the presence of a slip. The study shows that the slip model performed quite well and there is a potential for improving the performance efficiency. Besides, multiple methods have been presented to enhance the performance of the above mentioned bearing system by selecting various combinations of parameters governing the system.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45564072","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}

引用次数: 0

Determination of loads on the body of a boxcar with elastic elements in the center sill 中间有弹性元件的车厢车体荷载的测定

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0451

O. Fomin, Vatulia Glib, Lovska Alyona

引用次数: 1

A model of isotope transport in the unsaturated zone, case study 不饱和带同位素输运模型，实例研究

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0427

J. Chudoba, J. Královcová, J. Landa, J. Maryska, J. Říha

引用次数: 1

Active disturbance rejection control-based anti-coupling method for conical magnetic bearings 基于主动抗扰控制的圆锥磁悬浮轴承抗耦合方法