Pub Date : 2022-06-27DOI: 10.1080/13287982.2022.2092949
M. Wasim, Osmar Oliveira
ABSTRACT Volumetric steel structures are commonly used in the construction of modular buildings to overcome environmental hazards, control wastage, minimise construction safety issues, improve productivity and cost-effectiveness, reduce labour, and execute quick project completion. An adequate structural design and effective manufacturing are both integral processes to produce efficient and durable volumetric steel structures. Design for Manufacture and Assembly (DfMA) principles known for efficient design in the automobile industry can significantly improve the design of volumetric steel structures in terms of overall cost, safety, sustainability, productivity and time. The current research presents a case study of a volumetric steel structure in which structural design and DfMA approaches were integrated, and 3D visualisation was achieved by Building Information Model (BIM) and Solidworks that has limited previous research. The findings of this research reveal sustainable, material and cost optimised design for the prefabricated 3D steel structures. Furthermore, the novelty of the current research is enhanced by proposing a model for the automated efficient design and production of volumetric steel structures.
{"title":"Efficient design of a prefabricated steel structure integrating design for manufacture and assembly concepts","authors":"M. Wasim, Osmar Oliveira","doi":"10.1080/13287982.2022.2092949","DOIUrl":"https://doi.org/10.1080/13287982.2022.2092949","url":null,"abstract":"ABSTRACT Volumetric steel structures are commonly used in the construction of modular buildings to overcome environmental hazards, control wastage, minimise construction safety issues, improve productivity and cost-effectiveness, reduce labour, and execute quick project completion. An adequate structural design and effective manufacturing are both integral processes to produce efficient and durable volumetric steel structures. Design for Manufacture and Assembly (DfMA) principles known for efficient design in the automobile industry can significantly improve the design of volumetric steel structures in terms of overall cost, safety, sustainability, productivity and time. The current research presents a case study of a volumetric steel structure in which structural design and DfMA approaches were integrated, and 3D visualisation was achieved by Building Information Model (BIM) and Solidworks that has limited previous research. The findings of this research reveal sustainable, material and cost optimised design for the prefabricated 3D steel structures. Furthermore, the novelty of the current research is enhanced by proposing a model for the automated efficient design and production of volumetric steel structures.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"2 1","pages":"356 - 369"},"PeriodicalIF":1.1,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76319851","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 : 2022-06-18DOI: 10.1080/13287982.2022.2088654
A. Jabbar, D. Mohammed, M. J. Hamood
ABSTRACT Transverse shear reinforcement is usually used to resist the induced shear stresses in conventional concrete beams. Ultra-high performance concrete (UHPC) with fibres has high strength, post-peak strength, and strain softening. Such features can impact the behavior of the beam under loading. This paper presents the results of experimental tests performed on simply supported UHPC T-beams with basalt or steel fibres, with or without stirrups, subjected to four-point bending loads. The volume fraction of basalt fibres, the shear span, and the presence of stirrups are adopted as parameters. The possibility of achieving equivalent performance by using basalt or steel fibres, as shear micro-reinforcement, instead of using traditional steel stirrups is discussed from viewpoint of the beam structural behavior due to shear stress. The results show that the shear resistance increases with increasing fibre content and decreases with increasing shear span. The addition of basalt or steel fibres alters the fracture from brittle to ductile. Also, it is possible to partially replace the stirrups by using 1.0 % or more steel fibres or 0.5-1.0 % basalt fibres in the UHPC matrix. However, it is preferable to use a considerable ratio of shear rebars to avoid the dominance of shear failure.
{"title":"Using Fibers instead of Stirrups for Shear in Ultra-High Performance Concrete T-beams","authors":"A. Jabbar, D. Mohammed, M. J. Hamood","doi":"10.1080/13287982.2022.2088654","DOIUrl":"https://doi.org/10.1080/13287982.2022.2088654","url":null,"abstract":"ABSTRACT Transverse shear reinforcement is usually used to resist the induced shear stresses in conventional concrete beams. Ultra-high performance concrete (UHPC) with fibres has high strength, post-peak strength, and strain softening. Such features can impact the behavior of the beam under loading. This paper presents the results of experimental tests performed on simply supported UHPC T-beams with basalt or steel fibres, with or without stirrups, subjected to four-point bending loads. The volume fraction of basalt fibres, the shear span, and the presence of stirrups are adopted as parameters. The possibility of achieving equivalent performance by using basalt or steel fibres, as shear micro-reinforcement, instead of using traditional steel stirrups is discussed from viewpoint of the beam structural behavior due to shear stress. The results show that the shear resistance increases with increasing fibre content and decreases with increasing shear span. The addition of basalt or steel fibres alters the fracture from brittle to ductile. Also, it is possible to partially replace the stirrups by using 1.0 % or more steel fibres or 0.5-1.0 % basalt fibres in the UHPC matrix. However, it is preferable to use a considerable ratio of shear rebars to avoid the dominance of shear failure.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"37 1","pages":"36 - 49"},"PeriodicalIF":1.1,"publicationDate":"2022-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77653453","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 : 2022-06-16DOI: 10.1080/13287982.2022.2088055
H. Mousavi, S. Sabbagh Yazdi, M. Almohammad-albakkar
ABSTRACT In this paper, a new method is presented for designing nonlinear viscous dampers to improve the seismic response of multi-storey frames with braces. In this regard, a 2/3-scale three-storey steel structure is used as a benchmark case. Considering the cylindrical friction damper equipment on the bracings, the optimum slip loads are calculated for cylindrical friction damper of all stories under selected earthquakes records. For three earthquakes in optimised slip loads, the force versus the difference between velocities of two ends of cylindrical friction dampers for all stories is combined and plotted according to the velocity range for all earthquakes. Finally, the velocity–force curve is fitted and used for finding the design parameter of nonlinear viscous dampers. Similarly, the aforementioned steps are applied for El-Centro with three scales (of 50, 100 and 200% El Centro). According to the analysis results, the viscous dampers which are designed by using this approach present better performance than that of cylindrical friction dampers and considerably reduce the structural response. The values of displacement, acceleration and base shear are reduced between 63–96%, 44–85% and 14–78%, respectively. Moreover, the results of viscous dampers designed using three and one earthquakes are very similar.
本文提出了一种设计非线性粘性阻尼器的新方法，以改善带支撑的多层框架的地震响应。在这方面，采用了一个2/3比例的三层钢结构作为基准案例。考虑支撑柱上的圆柱摩擦减振器装置，在选定的地震记录下，计算了各层圆柱摩擦减振器的最佳滑移荷载。对于优化滑动载荷下的三次地震，根据所有地震的速度范围，将所有楼层的力与圆柱形摩擦阻尼器两端的速度差进行组合并绘制。最后，对速度-力曲线进行拟合，求出非线性粘性阻尼器的设计参数。同样，上述步骤适用于El-Centro的三个尺度(50,100和200% El Centro)。分析结果表明，采用该方法设计的粘性阻尼器性能优于圆柱摩擦阻尼器，并能显著降低结构响应。位移、加速度和基底剪切值分别减小63-96%、44-85%和14-78%。此外，用三次地震和一次地震设计粘性阻尼器的结果非常相似。
{"title":"A novel method for efficient design of frame structures equipped with nonlinear viscous dampers by using computational results of cylindrical friction damper","authors":"H. Mousavi, S. Sabbagh Yazdi, M. Almohammad-albakkar","doi":"10.1080/13287982.2022.2088055","DOIUrl":"https://doi.org/10.1080/13287982.2022.2088055","url":null,"abstract":"ABSTRACT In this paper, a new method is presented for designing nonlinear viscous dampers to improve the seismic response of multi-storey frames with braces. In this regard, a 2/3-scale three-storey steel structure is used as a benchmark case. Considering the cylindrical friction damper equipment on the bracings, the optimum slip loads are calculated for cylindrical friction damper of all stories under selected earthquakes records. For three earthquakes in optimised slip loads, the force versus the difference between velocities of two ends of cylindrical friction dampers for all stories is combined and plotted according to the velocity range for all earthquakes. Finally, the velocity–force curve is fitted and used for finding the design parameter of nonlinear viscous dampers. Similarly, the aforementioned steps are applied for El-Centro with three scales (of 50, 100 and 200% El Centro). According to the analysis results, the viscous dampers which are designed by using this approach present better performance than that of cylindrical friction dampers and considerably reduce the structural response. The values of displacement, acceleration and base shear are reduced between 63–96%, 44–85% and 14–78%, respectively. Moreover, the results of viscous dampers designed using three and one earthquakes are very similar.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"46 1","pages":"50 - 66"},"PeriodicalIF":1.1,"publicationDate":"2022-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80369018","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 : 2022-06-14DOI: 10.1080/13287982.2022.2087845
Tamer Eljufout, N. Hadadin, A. Haddad, Fadi Alhomaidat
ABSTRACT Rebound hammer (RH) is a non-destructive testing (NDT) technique that has a significant role in the field assessment of ancient and modern buildings made of natural stones. This study aims to establish correlation models for utilising the RH technique in evaluating weathered limestone walls and to provide an efficient in-situ assessment. Compressive and RH tests were conducted for four types of building limestones: Ruwaished Hard, Ruwaished Soft, Hallabat, and Ma’an, including nine specimens for each type with dimensions of 15 × 15 × 15 cm and two real-scale weathered stone walls with dimensions of 100 × 200 cm. Based on the experimental tests, regression analyses were conducted between the RH values, compressive strength, and modulus of elasticity. The established power-based correlation models had high coefficients of determination. For validation purposes, real-scale weathered stone walls were evaluated using the RH test, the mechanical properties were underestimated and affected by Stone Units’ surface roughness and weathering degrees. However, the established models give conservative estimations and can be used with sufficient accuracy for an in-situ evaluation of limestone structures. Further investigations are necessary to enhance models’ validity for various stone types by combining other NDTs and considering different weathering factors.
{"title":"Correlation models for utilising rebound hammer technique in evaluating weathered limestone walls","authors":"Tamer Eljufout, N. Hadadin, A. Haddad, Fadi Alhomaidat","doi":"10.1080/13287982.2022.2087845","DOIUrl":"https://doi.org/10.1080/13287982.2022.2087845","url":null,"abstract":"ABSTRACT Rebound hammer (RH) is a non-destructive testing (NDT) technique that has a significant role in the field assessment of ancient and modern buildings made of natural stones. This study aims to establish correlation models for utilising the RH technique in evaluating weathered limestone walls and to provide an efficient in-situ assessment. Compressive and RH tests were conducted for four types of building limestones: Ruwaished Hard, Ruwaished Soft, Hallabat, and Ma’an, including nine specimens for each type with dimensions of 15 × 15 × 15 cm and two real-scale weathered stone walls with dimensions of 100 × 200 cm. Based on the experimental tests, regression analyses were conducted between the RH values, compressive strength, and modulus of elasticity. The established power-based correlation models had high coefficients of determination. For validation purposes, real-scale weathered stone walls were evaluated using the RH test, the mechanical properties were underestimated and affected by Stone Units’ surface roughness and weathering degrees. However, the established models give conservative estimations and can be used with sufficient accuracy for an in-situ evaluation of limestone structures. Further investigations are necessary to enhance models’ validity for various stone types by combining other NDTs and considering different weathering factors.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"106 1","pages":"77 - 87"},"PeriodicalIF":1.1,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81189587","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 : 2022-05-29DOI: 10.1080/13287982.2022.2070958
Omar El Gendy, Ezzaat A. Sallam, M. Mohamedien
ABSTRACT A numerical formulation was carried out in this paper to produce the tangent stiffness matrix for two-nodal tapered Timoshenko beam-column elements for geometrically nonlinear analysis. The proposed solution is based on the exact shape functions and their derivatives describing the non-uniformity of the element properties. The section properties were presented as exponential functions with tapering indices to illustrate the variations in section properties along the tapered element length. The model is applicable for elements with different solid and hollow cross-sections. The proposed formulation is embedded into a Visual Basic code to carry out the analysis accompanied by many examples for validating its accuracy and efficiency. The model results are compared with those of commercial software and cited references that showed high accurate results with a small number of elements.
{"title":"Finite element formulation of Timoshenko tapered beam-column element for large displacement analysis based on the exact shape functions","authors":"Omar El Gendy, Ezzaat A. Sallam, M. Mohamedien","doi":"10.1080/13287982.2022.2070958","DOIUrl":"https://doi.org/10.1080/13287982.2022.2070958","url":null,"abstract":"ABSTRACT A numerical formulation was carried out in this paper to produce the tangent stiffness matrix for two-nodal tapered Timoshenko beam-column elements for geometrically nonlinear analysis. The proposed solution is based on the exact shape functions and their derivatives describing the non-uniformity of the element properties. The section properties were presented as exponential functions with tapering indices to illustrate the variations in section properties along the tapered element length. The model is applicable for elements with different solid and hollow cross-sections. The proposed formulation is embedded into a Visual Basic code to carry out the analysis accompanied by many examples for validating its accuracy and efficiency. The model results are compared with those of commercial software and cited references that showed high accurate results with a small number of elements.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"119 1","pages":"269 - 288"},"PeriodicalIF":1.1,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80370315","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 : 2022-05-24DOI: 10.1080/13287982.2022.2079165
H. Saleh, R. Kalfat, Kamiran Abduka, R. Al-Mahaidi
ABSTRACT Punching shear strengthening of existing reinforced concrete (RC) flat slabs can be required due to increased loads or design/construction defect. One of the more effective punching shear strengthening solutions, which has shown promising results is the use of post-installed L-shaped carbon fibre-reinforced polymer (L-CFRP) laminates bonded into predrilled holes through the slab in specific shear perimeter arrangements around the column. This paper presents an extensive finite element analysis (FEA) into RC slabs strengthened in punching shear using L-CFRP laminates. FEA models were developed using an existing experimental study as the baseline. After successful model calibration, parametric studies were used to explore the influence of critical parameters such as the concrete strength (32, 40 and 60 MPa) and the number of shear perimeters on the resulting punching shear capacity. In total, four RC slabs were modelled including an unstrengthened control specimen and an additional three specimens with different strengthening arrangements. A bond-slip model was introduced between the CFRP and the concrete and its calibration was described in this paper. Simulation results are compared with the experimental results in terms of load–deflection behaviour, FRP strains and crack patterns. The predicted peak loads calculated from the design codes and critical shear crack theory (CSCT) are compared and discussed in conjunction with the experimental and FEA results. The failure mode for the slabs were also compared with design codes and CSCT theory predictions. The study demonstrated the FEA results to have a good agreement with the experimental results in terms of load deflection behaviour, failure mode and L-CFRP strains.
{"title":"Finite element modelling of RC slabs strengthened against punching shear with L-CFRP laminates","authors":"H. Saleh, R. Kalfat, Kamiran Abduka, R. Al-Mahaidi","doi":"10.1080/13287982.2022.2079165","DOIUrl":"https://doi.org/10.1080/13287982.2022.2079165","url":null,"abstract":"ABSTRACT Punching shear strengthening of existing reinforced concrete (RC) flat slabs can be required due to increased loads or design/construction defect. One of the more effective punching shear strengthening solutions, which has shown promising results is the use of post-installed L-shaped carbon fibre-reinforced polymer (L-CFRP) laminates bonded into predrilled holes through the slab in specific shear perimeter arrangements around the column. This paper presents an extensive finite element analysis (FEA) into RC slabs strengthened in punching shear using L-CFRP laminates. FEA models were developed using an existing experimental study as the baseline. After successful model calibration, parametric studies were used to explore the influence of critical parameters such as the concrete strength (32, 40 and 60 MPa) and the number of shear perimeters on the resulting punching shear capacity. In total, four RC slabs were modelled including an unstrengthened control specimen and an additional three specimens with different strengthening arrangements. A bond-slip model was introduced between the CFRP and the concrete and its calibration was described in this paper. Simulation results are compared with the experimental results in terms of load–deflection behaviour, FRP strains and crack patterns. The predicted peak loads calculated from the design codes and critical shear crack theory (CSCT) are compared and discussed in conjunction with the experimental and FEA results. The failure mode for the slabs were also compared with design codes and CSCT theory predictions. The study demonstrated the FEA results to have a good agreement with the experimental results in terms of load deflection behaviour, failure mode and L-CFRP strains.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"158 1","pages":"338 - 355"},"PeriodicalIF":1.1,"publicationDate":"2022-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73757454","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 : 2022-05-18DOI: 10.1080/13287982.2022.2073954
C. Liu, Xizhi Wu, Xianjun Li, Yiqiang Wu
ABSTRACT Carbon fiber-reinforced polymer (CFRP) laminates can significantly improve the flexural performance of the bamboo scrimber. This study evaluated the effects of three fabrication methods (one-time hot pressing, secondary hot pressing, and secondary cold pressing) on the flexural performance of CFRP-bamboo scrimber composites. Four-point bending experiments and theoretical analysis were conducted to study the failure modes, flexural performance, load-displacement relationships and strain curves over time of CFRP-bamboo scrimber composites. Besides a theoretical model was proposed to describe the flexural stiffness of CFRP-bamboo scrimber composites. The results indicated that the CFRP-bamboo scrimber composite specimens demonstrated four failure modes depending on the treatment methods. Overall, the static flexural modulus of the one-time hot pressed specimens was superior (up to 1.93 times that of the untreated bamboo scrimber specimen), and the static flexural strength of the secondary cold pressing specimens was superior (up to 3.58 times greater than that of the untreated bamboo scrimber specimen), although neither the static flexural modulus nor the static flexural strength of the secondary hot pressing specimens was satisfactory. Finally, it was illustrated that the theoretical models, established to describe the load-displacement, could accurately predict the experimental results.
{"title":"Investigation into the effects of various processing treatments on the flexural performance of carbon fiber reinforced polymer-bamboo scrimber composites","authors":"C. Liu, Xizhi Wu, Xianjun Li, Yiqiang Wu","doi":"10.1080/13287982.2022.2073954","DOIUrl":"https://doi.org/10.1080/13287982.2022.2073954","url":null,"abstract":"ABSTRACT Carbon fiber-reinforced polymer (CFRP) laminates can significantly improve the flexural performance of the bamboo scrimber. This study evaluated the effects of three fabrication methods (one-time hot pressing, secondary hot pressing, and secondary cold pressing) on the flexural performance of CFRP-bamboo scrimber composites. Four-point bending experiments and theoretical analysis were conducted to study the failure modes, flexural performance, load-displacement relationships and strain curves over time of CFRP-bamboo scrimber composites. Besides a theoretical model was proposed to describe the flexural stiffness of CFRP-bamboo scrimber composites. The results indicated that the CFRP-bamboo scrimber composite specimens demonstrated four failure modes depending on the treatment methods. Overall, the static flexural modulus of the one-time hot pressed specimens was superior (up to 1.93 times that of the untreated bamboo scrimber specimen), and the static flexural strength of the secondary cold pressing specimens was superior (up to 3.58 times greater than that of the untreated bamboo scrimber specimen), although neither the static flexural modulus nor the static flexural strength of the secondary hot pressing specimens was satisfactory. Finally, it was illustrated that the theoretical models, established to describe the load-displacement, could accurately predict the experimental results.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"255 1","pages":"370 - 386"},"PeriodicalIF":1.1,"publicationDate":"2022-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78224464","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 : 2022-05-17DOI: 10.1080/13287982.2022.2075136
Chandrasekhar Reddy K, R. N
ABSTRACT The majority of the world’s waste does not go through the recycling process. Moreover, in the suburbs, waste growth and disposal impose a significant risk to the environment. Two distinct waste materials, such as palm oil fuel ash (POFA) and sugar cane bagasse ash (SCBA), are used as basic materials in this research, with weight fractions of 0%, 5.0%, 10.0%, 15.0%, 20.0%, and 25.0%, respectively, to substitute for grade 50 MPa concrete. Mechanical properties such as flexural strength, tensile and compressive strength of hybrid reinforced blended concrete were examined in the primary phase at 28 days of age. The study proposed an alternative mixture for each hybrid fibre combination. The durable properties such as sorptivity, saturated water absorption, acid resistance, and sulphate resistance of quaternary blended concrete with optimum hybrid materials were studied in the secondary phase. From the experimental investigation, mechanical properties are enhanced, and higher compressive and flexural strength are achieved as 64 MPa and 7.93 MPa in addition to 20% POFA and SCBA particles. The durable properties of quaternary blended concrete are enhanced properties due to the addition of hybrid materials.
{"title":"Experimental Studies on Durability and Mechanical Characteristics of Concrete using POFA and SCBA hybridization","authors":"Chandrasekhar Reddy K, R. N","doi":"10.1080/13287982.2022.2075136","DOIUrl":"https://doi.org/10.1080/13287982.2022.2075136","url":null,"abstract":"ABSTRACT The majority of the world’s waste does not go through the recycling process. Moreover, in the suburbs, waste growth and disposal impose a significant risk to the environment. Two distinct waste materials, such as palm oil fuel ash (POFA) and sugar cane bagasse ash (SCBA), are used as basic materials in this research, with weight fractions of 0%, 5.0%, 10.0%, 15.0%, 20.0%, and 25.0%, respectively, to substitute for grade 50 MPa concrete. Mechanical properties such as flexural strength, tensile and compressive strength of hybrid reinforced blended concrete were examined in the primary phase at 28 days of age. The study proposed an alternative mixture for each hybrid fibre combination. The durable properties such as sorptivity, saturated water absorption, acid resistance, and sulphate resistance of quaternary blended concrete with optimum hybrid materials were studied in the secondary phase. From the experimental investigation, mechanical properties are enhanced, and higher compressive and flexural strength are achieved as 64 MPa and 7.93 MPa in addition to 20% POFA and SCBA particles. The durable properties of quaternary blended concrete are enhanced properties due to the addition of hybrid materials.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"13 1","pages":"387 - 398"},"PeriodicalIF":1.1,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84927003","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 : 2022-05-03DOI: 10.1080/13287982.2022.2070112
A. Habibi, M. Izadpanah, Yaser Namdar
ABSTRACT Pushover analysis is a nonlinear procedure that is widely used as the primary tool for the nonlinear analysis of structures. In the conventional pushover method, the fundamental mode of the structure is selected as the dominant response mode of the multi degree of freedom (MDOF) system while neglecting the influence of higher modes. It has been proved that for many structures, higher vibration mode effects should be considered to boost the outcomes of the pushover analysis. In this study, a new Modal Load Pattern (MLP) is developed to improve pushover analysis procedure in estimating nonlinear responses of structures. For this purpose, MLP is defined by the directed algebraic combination of the weighted vibration mode-shape vectors of the structure. The weights of modes are determined using an optimisation algorithm such that the difference between the nonlinear responses of the structure under MLP and1 those of nonlinear time-history analysis is reduced to the minimum possible value. Comparing the outcomes of MLP with some well-known lateral load distributions shows that the proposed method increases the accuracy of responses resulting from pushover analysis. It is illustrated that against elastic behaviour, in the inelastic range of structural behaviour, it is likely that higher modes have a significant effect on the optimal lateral load distribution.
{"title":"A new modal lateral load pattern for improving pushover analysis to estimate nonlinear responses of structures","authors":"A. Habibi, M. Izadpanah, Yaser Namdar","doi":"10.1080/13287982.2022.2070112","DOIUrl":"https://doi.org/10.1080/13287982.2022.2070112","url":null,"abstract":"ABSTRACT Pushover analysis is a nonlinear procedure that is widely used as the primary tool for the nonlinear analysis of structures. In the conventional pushover method, the fundamental mode of the structure is selected as the dominant response mode of the multi degree of freedom (MDOF) system while neglecting the influence of higher modes. It has been proved that for many structures, higher vibration mode effects should be considered to boost the outcomes of the pushover analysis. In this study, a new Modal Load Pattern (MLP) is developed to improve pushover analysis procedure in estimating nonlinear responses of structures. For this purpose, MLP is defined by the directed algebraic combination of the weighted vibration mode-shape vectors of the structure. The weights of modes are determined using an optimisation algorithm such that the difference between the nonlinear responses of the structure under MLP and1 those of nonlinear time-history analysis is reduced to the minimum possible value. Comparing the outcomes of MLP with some well-known lateral load distributions shows that the proposed method increases the accuracy of responses resulting from pushover analysis. It is illustrated that against elastic behaviour, in the inelastic range of structural behaviour, it is likely that higher modes have a significant effect on the optimal lateral load distribution.","PeriodicalId":45617,"journal":{"name":"Australian Journal of Structural Engineering","volume":"128 1","pages":"289 - 302"},"PeriodicalIF":1.1,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87638942","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 : 2022-04-22DOI: 10.1080/13287982.2022.2066610
S. Fernando, Jessey Lee, Y. Oktavianus
ABSTRACT A hydraulic load cell is a simple onsite load measurement device for quality assurance of structural fasteners. While these load cells can be used to establish torque-tension relationship, due to their reduced stiffness compared to electronic load cells, prominent standards such as EN14399-2 prevents the use of hydraulic load cells in bolt assemblies testing where nut rotational angle is also of importance. Since the significant angular parameter used in EN14399-2 is a difference of two angles, it can be argued that when the difference of angle is considered, the reduced stiffness effect of hydraulic load cell could be negated. This paper provides both theoretical and experimental validation of using an electronic and a hydraulic load cell to carry out the fit-for-purpose assembly test as prescribed in EN14399-2. Results show that a hydraulic load cell can be used as a simple onsite screening test to improve quality assurance of structural bolt assemblies on construction sites. The Australian Standard for fastener assemblies AS/NZS 1252:2016 requires a test regime to ensure the supplied bolts are suitable for its intended application. The methodology developed in this paper maybe used to screen the quality of the supplied fasteners on-site before being used in the assembly.
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