Pub Date : 2020-04-20DOI: 10.33430/v27n1thie-2018-0024
M. Shanmugam, P. Rajesh
This paper proposes a hybrid methodology to improve the dynamic strength of frameworks by optimally locating and sizing the unified power flow controller (UPFC). The proposed method combines both the antlion optimiser (ALO) and invasive weed optimisation (IWO) techniques. The advantages of the proposed methodology are enhanced searching ability, better identification of optimal solutions and greater reliability. Initially, to locate UPFCs, using the ALO technique, the most extreme power loss bus is recognised as the optimal location. The capacity required to resolve the situation is determined by the IWO technique based on the minimum power loss, voltage deviation and establishment cost of the UPFCs. The proposed system is actualised and aims at the matrix laboratory (MATLAB) environment, while the power flow security and voltage stability are evaluated on the basis of the Institute of Electrical and Electronics Engineers (IEEE) standard benchmark system. At this point, voltage stability, power loss, overloading and UPFC costs are analysed through changing the system load and generation. The proposed working method is then assessed and compared with traditional techniques.
{"title":"Ideal position and size selection of unified power flow controllers (UPFCs) to upgrade the dynamic stability of systems: An antlion optimiser and invasive weed optimisation Algorithm","authors":"M. Shanmugam, P. Rajesh","doi":"10.33430/v27n1thie-2018-0024","DOIUrl":"https://doi.org/10.33430/v27n1thie-2018-0024","url":null,"abstract":"This paper proposes a hybrid methodology to improve the dynamic strength of frameworks by optimally locating and sizing the unified power flow controller (UPFC). The proposed method combines both the antlion optimiser (ALO) and invasive weed optimisation (IWO) techniques. The advantages of the proposed methodology are enhanced searching ability, better identification of optimal solutions and greater reliability. Initially, to locate UPFCs, using the ALO technique, the most extreme power loss bus is recognised as the optimal location. The capacity required to resolve the\u0000situation is determined by the IWO technique based on the minimum power loss, voltage deviation and establishment cost of the UPFCs. The proposed system is actualised and aims at the matrix laboratory (MATLAB) environment, while the\u0000power flow security and voltage stability are evaluated on the basis of the Institute of Electrical and Electronics Engineers (IEEE) standard benchmark system. At this point, voltage stability, power loss, overloading and UPFC costs are analysed through changing the system load and generation. The proposed working method is then assessed and compared with traditional techniques.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":"25-37"},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44905664","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 : 2020-04-20DOI: 10.33430/v27n1thie2017-0054
S. Mondal, S. Mandal
This study attempts to assess the role of basin morphometric parameters in slope instability using a morphometric diversity (MD) model, as well as the role of drainage parameters and relief parameters in slope failure using drainage diversity (DD) and relief diversity (RD) models, respectively. For this, a total of 14 morphometric data layers were considered. The relationship of each data layer to landslide susceptibility was judged using a frequency ratio (FR) approach. Parameters like drainage density (Dd), drainage frequency (Df), relative relief (Rr), drainage texture (Dt), junction frequency (Jf), infiltration number (In), ruggedness index (Ri), dissection index (Di), elevation (E), slope (S), relief ratio (Rra) and hypsometric integral (Hi) were positively related with landslide potentiality while bifurcation ratio (Rb) and drainage intensity (Din) negatively correlated with S failure. The principal component analysis (PCA)-based weight assigned to each data layer in each model was multiplied with unidirectional reclassified data layers for each model using a weighted linear combination (WLC) approach to prepare landslide susceptibility maps. The receiver operating characteristics curve showed that the landslide prediction accuracy of the DD, RD and MD models were 71.4%, 73.9% and 76.3%, respectively. The FR plots of the aforesaid three models suggested that the chance of landslide increases from very low to very high in susceptible zones.
{"title":"Geomorphic diversity and landslide susceptibility in the Balason River Basin, Darjeeling Himalaya","authors":"S. Mondal, S. Mandal","doi":"10.33430/v27n1thie2017-0054","DOIUrl":"https://doi.org/10.33430/v27n1thie2017-0054","url":null,"abstract":"This study attempts to assess the role of basin morphometric parameters in slope instability using a morphometric diversity (MD) model, as well as the role of drainage parameters and relief parameters in slope failure using drainage diversity (DD) and relief diversity (RD) models, respectively. For this, a total of 14 morphometric data layers were\u0000considered. The relationship of each data layer to landslide susceptibility was judged using a frequency ratio (FR) approach. Parameters like drainage density (Dd), drainage frequency (Df), relative relief (Rr), drainage texture (Dt), junction frequency (Jf), infiltration number (In), ruggedness index (Ri), dissection index (Di), elevation (E), slope (S), relief ratio (Rra) and hypsometric integral (Hi) were positively related with landslide potentiality while bifurcation ratio (Rb) and drainage intensity (Din) negatively correlated with S failure. The principal component analysis (PCA)-based weight assigned to each data layer in each model was multiplied with unidirectional reclassified data layers for each model using a weighted linear combination (WLC) approach to prepare landslide susceptibility maps. The receiver operating characteristics curve showed that the landslide prediction accuracy of the DD, RD and MD models were 71.4%, 73.9% and 76.3%, respectively. The FR plots of the aforesaid three models suggested that the chance of landslide increases from very low to very high in susceptible zones.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":"13-24"},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49659765","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 : 2020-04-20DOI: 10.33430/v27n1thie-2017-0052
H. Wong
With the recent advancement in technology, the method, accuracy and speed of slope stability analysis have been vastly improved. Nevertheless, the reliability and appropriateness of such analysis can be very much in doubt if the soil behaviour, in particular the shear strength behaviour, is not fully understood. The objective of this paper is therefore to evaluate the shear strength behaviour of various soil types in Hong Kong. This comprises the collection, processing and analysis of the laboratory and field works carried out in the past few decades, in particular the triaxial compression testing in the laboratory and standard penetration test (SPT) in the field. For correlating SPT with soil shear strength, a fairly large number of carefully controlled site investigation works with SPT are carried out both above and below any Mazier sampling. Laboratory triaxial tests are then carried out in these Mazier samples. Finally, it is hoped that a basically quantitative relationship between soil shear strength and SPT can be obtained as this would enable a soil shear strength profile to be established once the corresponding SPT profile has been determined on site by carrying out SPT in adequate number of drill holes.
{"title":"Shear strength properties of Hong Kong soils for slope stability","authors":"H. Wong","doi":"10.33430/v27n1thie-2017-0052","DOIUrl":"https://doi.org/10.33430/v27n1thie-2017-0052","url":null,"abstract":"With the recent advancement in technology, the method, accuracy and speed of slope stability analysis have been vastly improved. Nevertheless, the reliability and appropriateness of such analysis can be very much in doubt if the soil behaviour, in particular the shear strength behaviour, is not fully understood.\u0000The objective of this paper is therefore to evaluate the shear strength behaviour of various soil types in Hong Kong. This comprises the collection, processing and analysis of the laboratory and field works carried out in the past few decades, in particular the triaxial compression testing in the laboratory and standard penetration test (SPT) in the field. For correlating SPT with soil shear strength, a fairly large number of carefully controlled site investigation works with SPT are carried out both above and below any Mazier sampling. Laboratory triaxial tests are then carried out in these Mazier samples.\u0000Finally, it is hoped that a basically quantitative relationship between soil shear strength and SPT can be obtained as this would enable a soil shear strength profile to be established once the corresponding SPT profile has been determined on site by carrying out SPT in adequate number of drill holes.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":"48-54"},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45278615","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 : 2020-04-20DOI: 10.33430/v27n1thie-2019-0012
B. Tang, Yu Gu, Jianming Ling, Lihong He, Fan Yang
In order to evaluate effects of waterborne epoxy resin prepared by the phase-inversion method (phase-inversion waterborne epoxy resin) on properties of waterborne epoxy emulsified asphalt for cold patch engineering of asphalt pavement, a series of methods for evaluating properties of emulsified asphalt and casting resin were used. Results show that, with an increase in waterborne epoxy resin content, penetration, ductility, surface curing time of waterborne epoxy emulsified asphalt decrease and its adhesion degree, shear strength and bond strength increase. Moreover, its penetration, ductility and adhesion degree remain unchanged when the content of waterborne epoxy resin exceeds 20%, and its shear strength and bond strength increase most remarkably when the content of waterborne epoxy resin increases from 10% to 20%. The test results are explained by the surface fluorescent micromorphology of cured waterborne epoxy emulsified asphalt that, with the increase in waterborne epoxy resin content, epoxy resin particles firstly appear as segregated spots, and then change from spotted status to clustered status, and the epoxy resin phase gradually becomes a continuous phase. In conclusion, phase-inversion waterborne epoxy resin has effects on properties of the cold patch waterborne epoxy emulsified asphalt, and recommended content of waterborne epoxy resin is 20%.
{"title":"Effects of phase-inversion waterborne epoxy resin on properties of cold patch waterborne epoxy emulsified asphalt","authors":"B. Tang, Yu Gu, Jianming Ling, Lihong He, Fan Yang","doi":"10.33430/v27n1thie-2019-0012","DOIUrl":"https://doi.org/10.33430/v27n1thie-2019-0012","url":null,"abstract":"In order to evaluate effects of waterborne epoxy resin prepared by the phase-inversion method (phase-inversion waterborne epoxy resin) on properties of waterborne epoxy emulsified asphalt for cold patch engineering of asphalt pavement, a series of methods for evaluating properties of emulsified asphalt and casting resin were used. Results show that, with an increase in waterborne epoxy resin content, penetration, ductility, surface curing time of waterborne epoxy emulsified asphalt decrease and its adhesion degree, shear strength and bond strength increase. Moreover, its penetration, ductility and adhesion degree remain unchanged when the content of waterborne epoxy resin exceeds 20%, and its shear strength and bond strength increase most remarkably when the content of waterborne epoxy resin increases from 10% to 20%. The test results are explained by the surface fluorescent micromorphology of cured waterborne epoxy emulsified asphalt that, with the increase in waterborne epoxy resin content, epoxy resin particles firstly appear as segregated spots, and then change from spotted status to clustered status, and the epoxy resin phase gradually becomes a continuous phase. In conclusion, phase-inversion waterborne epoxy resin has effects on properties of the cold patch waterborne epoxy emulsified asphalt, and recommended content of waterborne epoxy resin is 20%.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42251115","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 : 2020-04-10DOI: 10.33430/v27n1thie-2019-0030
G. Liu, E. Lee, R. Yuen
Time, cost and quality are major concerns in construction project management. To achieve a balance between time-cost and time-quality, a trade-off problem among time-cost-quality (TCQ) is proposed for optimisation by the application of a genetic algorithm (GA). A GA attempts to minimise a fitness function that describes the objective to be achieved. The fitness function is specifically designed according to the nature and characteristics of the construction project. By inputting the project parameters, the fitness function should be able to provide a balance between the time, cost and quality of the project. This study applied a GA to strategically search for the best project parameters for an offshore wind farm project to achieve a more accurate prediction for construction time, cost and quality of the project in the pre-construction stage. A series of practical mathematical models are developed through a review of previous studies based on specific merits, and a real offshore wind farm project is studied to identify and verify the applicability and viability of the mathematical models. After the process of optimisation, the results show that the output data is very close to the actual case in terms of construction time, cost and quality.
{"title":"Optimising the time-cost-quality (TCQ) trade-off in offshore wind farm project\u0000management with a genetic algorithm (GA)","authors":"G. Liu, E. Lee, R. Yuen","doi":"10.33430/v27n1thie-2019-0030","DOIUrl":"https://doi.org/10.33430/v27n1thie-2019-0030","url":null,"abstract":"Time, cost and quality are major concerns in construction project management. To achieve a balance between time-cost and time-quality, a trade-off problem among time-cost-quality (TCQ) is proposed for optimisation by the application of a genetic algorithm (GA). A GA attempts to minimise a fitness function that describes the objective to be achieved. The fitness function is specifically designed according to the nature and characteristics of the construction project. By inputting the project parameters, the fitness function should be able to provide a balance between the time, cost and quality of the project. This study applied a GA to strategically search for the best project parameters for an offshore wind farm project to achieve a more accurate prediction for construction time, cost and quality of the project in the pre-construction stage. A series of practical mathematical models are developed through a review of previous studies based on specific merits, and a real offshore wind farm project is studied to identify and verify the applicability and viability of the mathematical models. After the process of optimisation, the results show that the output data is very close to the actual case in terms of construction time, cost and quality.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2020-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48034470","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 : 2020-01-01DOI: 10.33430/v27n2thie-2019-0053
Bin Yong, J. Chen, Zuqiang Su, X. Pang, Xinghua Yang
{"title":"An optimised multiple kernel learning support vector machine (SVM) classification based on the fireworks algorithm and its application to the fault diagnosis of gearbox","authors":"Bin Yong, J. Chen, Zuqiang Su, X. Pang, Xinghua Yang","doi":"10.33430/v27n2thie-2019-0053","DOIUrl":"https://doi.org/10.33430/v27n2thie-2019-0053","url":null,"abstract":"","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69753446","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 : 2020-01-01DOI: 10.33430/V27N2THIE-2019-0033
D. Looi, Yuen Fai Augustus Lee, R. Su, Yanlong Zhang
Post-installed reinforcement (PIR) helps facilitate retrofitting works, mitigate misplaced reinforcement problems, as well as support newly cast concrete members such as modular integrated construction. However, it has not been holistically addressed in major international reinforced concrete (RC) design codes. Nonetheless, based on established design philosophy and associated failure modes, the cast-in reinforcement design method in RC can be extended to design qualified PIR systems. The qualification of PIR system can be referenced to Acceptance Criteria (AC) 308 (2016), European Assessment Document (EAD) 330087 (2018) and EAD 330499 (2017) in the US and Europe, respectively. In Hong Kong, PIR is conservatively limited to shear connections. Its assumption of pinned connection is less justifiable for some deep sections of beams, which may induce hogging moments, causing tension at the top reinforcement of the supports. In some cases of cantilever slabs, moment connections are necessary to maintain equilibrium. Hence, this paper reviews an up-to-date design methodology and installation guide to complement the Hong Kong Code of Practice for Structural Use of Concrete (HKBD) by referring to the recently published international design codes and documents. The proposal is useful to promote economical, sustainable and technically sound use of PIR system.
{"title":"Design and installation of post-installed reinforcements: A state-of-the-art review","authors":"D. Looi, Yuen Fai Augustus Lee, R. Su, Yanlong Zhang","doi":"10.33430/V27N2THIE-2019-0033","DOIUrl":"https://doi.org/10.33430/V27N2THIE-2019-0033","url":null,"abstract":"Post-installed reinforcement (PIR) helps facilitate retrofitting works, mitigate misplaced reinforcement problems, as well as support newly cast concrete members such as modular integrated construction. However, it has not been holistically addressed in major international reinforced concrete (RC) design codes. Nonetheless, based on established design philosophy and associated failure modes, the cast-in reinforcement design method in RC can be extended to design qualified PIR systems. The qualification of PIR system can be referenced to Acceptance Criteria (AC) 308 (2016), European Assessment Document (EAD) 330087 (2018) and EAD 330499 (2017) in the US and Europe, respectively. In Hong Kong, PIR is conservatively limited to shear connections. Its assumption of pinned connection is less justifiable for some deep sections of beams, which may induce hogging moments, causing tension at the top reinforcement of the supports. In some cases of cantilever slabs, moment connections are necessary to maintain equilibrium. Hence, this paper reviews an up-to-date design methodology and installation guide to complement the Hong Kong Code of Practice for Structural Use of Concrete (HKBD) by referring to the recently published international design codes and documents. The proposal is useful to promote economical, sustainable and technically sound use of PIR system.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69753345","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 : 2020-01-01DOI: 10.33430/v27n2thie-2017-0023
Guangli Sun, Jianming Ling, Zefeng Tao, J. Qian, Yang Cai
Cracks appear in the early cement stabilisation base due to shrinkage. Pavement service life is reduced by the reflecting cracks under load coupled with environment. Geosynthetics can be used as an effective anti-reflective crack material to improve the asphalt concrete performance. Related studies mainly focus on the optimal material type and placement location of geosynthetics. However, the mechanism research of anti-crack propagation is limited and needs further investigation. The methods used to date are hard to reveal the anti-reflective crack mechanism of geosythetics. Therefore, geosynthetic materials cannot be used appropriately. Propagation and resistance characteristics of traffic induced reflective cracks with geotextile placed in the asphalt layer was investigated using extended finite element model. The effects of geotextile placement and tensile modulus were also investigated. Compared with other zones, the geotextile stress over the crack was significantly larger. The geotextile absorbed 15% of the total stress in the asphalt surface layer. The crack propagation stages and final crack length was separate when tensile modulus of geotextile reached 50 MPa. The geotextile with 100 MPa tensile modulus was found to produce the optimal effect on preventing crack. Geotextile placed at a quarter depth of the asphalt layer from the bottom had the best crack resistance.
{"title":"Effect of geotextile on reduction of reflective cracking induced by traffic load in asphalt concrete","authors":"Guangli Sun, Jianming Ling, Zefeng Tao, J. Qian, Yang Cai","doi":"10.33430/v27n2thie-2017-0023","DOIUrl":"https://doi.org/10.33430/v27n2thie-2017-0023","url":null,"abstract":"Cracks appear in the early cement stabilisation base due to shrinkage. Pavement service life is reduced by the reflecting cracks under load coupled with environment. Geosynthetics can be used as an effective anti-reflective crack material to improve the asphalt concrete performance. Related studies mainly focus on the optimal material type and placement location of geosynthetics. However, the mechanism research of anti-crack propagation is limited and needs further investigation. The methods used to date are hard to reveal the anti-reflective crack mechanism of geosythetics. Therefore, geosynthetic materials cannot be used appropriately. Propagation and resistance characteristics of traffic induced reflective cracks with geotextile placed in the asphalt layer was investigated using extended finite element model. The effects of geotextile placement and tensile modulus were also investigated. Compared with other zones, the geotextile stress over the crack was significantly larger. The geotextile absorbed 15% of the total stress in the asphalt surface layer. The crack propagation stages and final crack length was separate when tensile modulus of geotextile reached 50 MPa. The geotextile with 100 MPa tensile modulus was found to produce the optimal effect on preventing crack. Geotextile placed at a quarter depth of the asphalt layer from the bottom had the best crack resistance.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69753494","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 : 2020-01-01DOI: 10.33430/v27n3thie-2017-0053
S. Chen, Yu-lun Ho
Nickel-based materials are widely used in making engine parts, compressor rotors and energy production. Nickel-based materials are resistant to corrosive conditions, and have a high strength in extreme temperatures. They also feature satisfactory mechanical properties in extreme heat. The use of these nickel-based super-alloys is on the rise every day as they have been widely used in military and civilian aeronautical industries in recent years. For this reason, it was the intention of this study to do optimised cutting experiments on Waspaloy in order to identify the significant factors which have impact on the tool life of cutting tools using the response surface methodology (RSM) in regression analysis. Several factors were found in the results that had significant impact on the machining tools’ life, including machining speed, depth, and feed rate. Finally, a regression analysis was adopted to establish a formula for calculating the service life of cutting tools. It was found that the minimum wear was achieved with the cutting speed at V = 33.21 m/min, cutting depth at dp = 0.0367 mm and feed per tooth at Ft = 0.367 mm/tooth.
{"title":"Application of response surface methodology (RSM) to the prediction of the service\u0000life of cutters used in milling super-alloy Waspaloy","authors":"S. Chen, Yu-lun Ho","doi":"10.33430/v27n3thie-2017-0053","DOIUrl":"https://doi.org/10.33430/v27n3thie-2017-0053","url":null,"abstract":"Nickel-based materials are widely used in making engine parts, compressor rotors and energy production. Nickel-based materials are resistant to corrosive conditions, and have a high strength in extreme temperatures. They also feature satisfactory mechanical properties in extreme heat. The use of these nickel-based super-alloys is on the rise every day as they have been widely used in military and civilian aeronautical industries in recent years. For this reason, it was the intention of this study to do optimised cutting experiments on Waspaloy in order to identify the significant factors which have impact on the tool life of cutting tools using the response surface methodology (RSM) in regression analysis. Several factors were found in the results that had significant impact on the machining tools’ life, including machining speed, depth, and feed rate. Finally, a regression analysis was adopted to establish a formula for calculating the service life of cutting tools. It was found that the minimum wear was achieved with the cutting speed at V = 33.21 m/min, cutting depth at dp = 0.0367 mm and feed per tooth at Ft = 0.367 mm/tooth.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":"103-112"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69753517","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 : 2020-01-01DOI: 10.33430/v27n2thie-2017-0038
K. Leung, L. Lau
Common computer programs generally model beam-column joint (BCJ) as a finite point without physical property that will neither yield nor fail. However, this assumption is not appropriate for modelling existing buildings without seismic provisions where the shear capacities of BCJs were uncertain. This paper presented the finite element analysis and cyclic load test results of four full-scale edge column BCJ specimens with and without column and BCJ shear link detailing according to seismic provisions. The aim was to compare the numerical analysis and experimental results to establish a reduction factor between BCJ with and without seismic detailing provisions and to verify the accuracy of numerical analysis results. With the proposed reduction factor, non-seismic provisioned BCJ that will fail under seismic actions can be determined from general computer analysis programs and correspondingly strengthened if necessary to ensure that yielding occurs in structural members connected to the joint instead of brittle joint shear failure. Furthermore, splitting crack along the lower column axis was observed in all non-seismic provisioned specimens due to eccentricity between the upper and lower column load centre and inadequate link confinement in the lower column.
{"title":"Seismic performance evaluation of reinforced concrete beam-column joints of existing buildings","authors":"K. Leung, L. Lau","doi":"10.33430/v27n2thie-2017-0038","DOIUrl":"https://doi.org/10.33430/v27n2thie-2017-0038","url":null,"abstract":"Common computer programs generally model beam-column joint (BCJ) as a finite point without physical property that will neither yield nor fail. However, this assumption is not appropriate for modelling existing buildings without seismic provisions where the shear capacities of BCJs were uncertain. This paper presented the finite element analysis and cyclic load test results of four full-scale edge column BCJ specimens with and without column and BCJ shear link detailing according to seismic provisions. The aim was to compare the numerical analysis and experimental results to establish a reduction factor between BCJ with and without seismic detailing provisions and to verify the accuracy of numerical analysis results. With the proposed reduction factor, non-seismic provisioned BCJ that will fail under seismic actions can be determined from general computer analysis programs and correspondingly strengthened if necessary to ensure that yielding occurs in structural members connected to the joint instead of brittle joint shear failure. Furthermore, splitting crack along the lower column axis was observed in all non-seismic provisioned specimens due to eccentricity between the upper and lower column load centre and inadequate link confinement in the lower column.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69753560","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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