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Papers by Madappa Sivasubramanian

Research paper thumbnail of Effect of Layer Thickness and FRP Reinforcement Ratio on the Load Carrying Capacity of ECC Composite Beams

Composites science and technology, 2023

Research paper thumbnail of Seismic Vulnerability Assessment of Multi-arch Gallery Masonry Bridges Adopting Different Seismic Analysis Procedures

Research Square (Research Square), Oct 17, 2022

India has one of the longest rail networks all over the world. The Indian railway network consist... more India has one of the longest rail networks all over the world. The Indian railway network consist of many heritage bridges which are still in service over span of 100 years. Some of these heritage bridges are located in the very high seismic zone which is threat to their structural integrity. Therefore, it is necessary to assess the performance of these bridges for the earthquake loading. For this purpose, this paper attempts to predict the seismic vulnerability of the two multi arch gallery bridges of UNESCO recognised Kalka Shimla Mountain Railway. In this paper, three dimensional numerical models of the bridges were developed in ABAQUS finite element environment. The macro-modelling strategy was followed along with the concrete damage plasticity model as constitutive model for stone masonry. Further, the seismic performance of the bridges was estimated by nonlinear static analysis and incremental dynamic analysis procedures. The nonlinear static analysis was performed adopting two lateral loading patterns and incremental dynamic analysis was performed using 30 accelerograms. The 30 accelerograms were matched with the site-specific spectra and then scaled to different level of peak ground acceleration. The results from the nonlinear static analysis and incremental dynamic analysis were presented in terms of control node displacement and location of tensile damages. Lastly, the comparison between nonlinear static analysis results and incremental dynamic analysis results were showed that confirms, incremental dynamic analysis results are more significant at very high computational time consumption.

Research paper thumbnail of Effect of ECC layer thickness and reinforcement ratio on the load carrying capacity of steel‐reinforced composite beams

Structural Concrete

The present study investigates the effect of Engineered Cementitious Composites (ECC) layer thick... more The present study investigates the effect of Engineered Cementitious Composites (ECC) layer thickness against various reinforcement ratios on the flexural performance of reinforced ECC–concrete composite beams. In total, 20 reinforced composite beams are selected from the literature to predict their flexural response using Finite Element (FE) analysis. In addition to the FE analyses, a detailed analytical study is performed using the strain compatibility procedure to predict the flexural strength of ECC–concrete composite beams. The results from the FE analyses are compared against the experimental results and are found to show a close agreement. Using the validated FE models, detailed parametric studies are conducted to determine the effectiveness of different design parameters such as (a) ECC height replacement for a reinforcement ratio, (b) reinforcement ratio for an ECC height replacement, and (c) adequate reinforcement ratio for effective strengthening. The results of the param...

Research paper thumbnail of Present day status and numerical modelling of heritage masonry bridges of Kalka-Shimla Mountain Railways

International journal of masonry research and innovation, 2022

Research paper thumbnail of Experimental Study on Flexural Behaviour of High Ductile Cementitious Composites

Research paper thumbnail of Modelos de Diseño Orientado a Tensión-deformación para Hormigón Flexible

Research paper thumbnail of Performance of ductile fibre-reinforced cementitious composite concrete frames under flexural loading

Proceedings of the ICE - Construction Materials, 2013

Results of an experimental study on flexural behaviour of steel-reinforced portal frames made of ... more Results of an experimental study on flexural behaviour of steel-reinforced portal frames made of ductile fibre-reinforced cementitious composite and concrete under static transverse bending are reported in this paper. A total of six half-scale frames were cast and tested. It was observed that the frames partially or fully made of ductile fibre-reinforced cementitious composite have about 21–37% higher load-carrying capacity than ordinary concrete frames. Moreover, frames completely made of ductile fibre-reinforced cementitious composite are shown to have 1·5–2 times more ductility than the control frame. The failure modes of ductile fibre-reinforced cementitious composite frames were very ductile with multiple microcracks and the general pattern was flexural tension. In addition to the frame specimens, ductile fibre-reinforced cementitious composite tensile coupons, compressive cylinders and concrete cubes were also cast and evaluated.

Research paper thumbnail of Performance of NSM-FRP RC beams in flexure and shear using locally developed CFRP rebars

International Journal of Sustainable Materials and Structural Systems, 2012

Research paper thumbnail of Micromechanics based design approach for understanding the behaviour of an ECC beam

ABSTRACT This paper deals with micromechanics based design approach for modeling the flexural beh... more ABSTRACT This paper deals with micromechanics based design approach for modeling the flexural behaviour of a steel reinforced Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) beam. First, micromechanical models were developed to evaluate the peak tensile strength and strain of PVA-ECC. Then, generalised stress-strain relationships were derived for both uni-axial tension and compression. Next, Stress block parameters, which are associated with respective stress-strain relationships, were derived. Finally, a model for evaluating the flexural capacity of an ECC beam was developed. The results obtained by testing the model were in agreement with other analytical results available in the literature. However, to confirm the flexural behaviour and develop a unified design approach more experimental investigations are needed. Generally, the yielding behaviour of structural steel provides the ductility to reinforced concrete structures over normal loadings. However, during earthquake excitation and heavy impact conditions structures undergo large deformations. To withstand such loads they need to have more ductility that is inherent. In this context, it is noteworthy that ductility of reinforcements prevents concrete from brittle cracking. However, ductility related concerns can be solved to a large extent by using ductile concrete materials such as Slurry Infiltrated Fibre Concrete (SIFCON), Slurry Infiltrated Mat Concrete (SIMCON) , Polyethylene Engineered Cementitious Composite (PE-ECC) and Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) in structural constructions.

Research paper thumbnail of Design Oriented Stress-Strain Models for Engineered Cementitious Composites

Revista de la construcción, 2016

Research paper thumbnail of Serviceability analysis and increased axle load performance of heritage arch gallery railway bridge

This investigation deals with the serviceability analysis and increased axle load performance of ... more This investigation deals with the serviceability analysis and increased axle load performance of Bridge No. 541 of UNESCO recognised Kalka Shimla Mountain Railways, which is a multi-storey arch gallery stone masonry bridge situated in the state of Himachal Pradesh, India. For this purpose, a finite element (FE) model was developed based on the drawings and reports available in Shimla Division, Northern Railways, India. Further, the results obtained from ambient vibration test (AVT) and operational modal analysis (OMA) is utilized to model update the initial FE model by modifying the mechanical properties of stone masonry. The serviceability against present-day axle loading (H Class Loading, Indian Railways) and present speed of the train is assessed. At last, a parametric study is conducted to understand the feasibility to attain higher speeds (up to 40 kmph) of the present axle load and higher axle load with different speeds of the train over the bridge to check the serviceabilit...

Research paper thumbnail of Seismic vulnerability assessment and fragility curves for a multistorey gallery arch bridge

SN Applied Sciences

The masonry bridges on the Kalka Shimla Mountain Railway line, which have multiple arch galleries... more The masonry bridges on the Kalka Shimla Mountain Railway line, which have multiple arch galleries in the form of Roman aqueducts, are spectacular. The Kalka Shimla Mountain Railway line is situated in severe seismic zones (Indian Standard 1893:2016). This research assesses the seismic vulnerability of masonry arch Bridge No. 541 situated on the Kalka Shimla Mountain Railway line. This bridge is the tallest on the route. In particular, it assesses the seismic vulnerability of the bridge using finite element (FE) analysis. For this purpose, an FE model for the bridge is developed using the ABAQUS FE-based environment. The experimental field study conducted on the bridge using an ambient vibration test (AVT) and dynamic parameters (frequency and mode shapes) is evaluated by operational modal analysis (OMA). Further, the FE model is updated by modifying the elastic mechanical property of the stone masonry to match the analytical modal frequency with the results of the AVT and OMA. The u...

Research paper thumbnail of System Identification of Heritage Structures through AVT and OMA: A Review

Structural Durability & Health Monitoring

In this review article, the past investigations carried out on heritage structures using Ambient ... more In this review article, the past investigations carried out on heritage structures using Ambient Vibration Test (AVT) and Operational Modal Analysis (OMA) for system identification (determination of dynamic properties like frequency, mode shape and damping ratios) and associated applications are summarized. A total of 68 major research studies on heritage structures around the world that are available in literature are surveyed for this purpose. At first, field investigations carried out on heritage structures prior to conducting AVT are explained in detail. Next, specifications of accelerometers, location of accelerometers and optimization of accelerometer networks have been elaborated with respect to the geometry of the heritage structures. In addition to this, ambient vibration loads and data acquisition procedures are also discussed. Further, the state of art of performing OMA techniques for heritage structures is explained briefly. Furthermore, various applications of system identification for heritage structures are documented. Finally, conclusions are made towards errorless system identification of heritage structures through AVT and OMA.

Research paper thumbnail of System Identification of Heritage Structures through AVT and OMA: A Review

Structural Durability & Health Monitoring, 2019

In this review article, the past investigations carried out on heritage structures using Ambient ... more In this review article, the past investigations carried out on heritage structures using Ambient Vibration Test (AVT) and Operational Modal Analysis (OMA) for system identification (determination of dynamic properties like frequency, mode shape and damping ratios) and associated applications are summarized. A total of 68 major research studies on heritage structures around the world that are available in literature are surveyed for this purpose. At first, field investigations carried out on heritage structures prior to conducting AVT are explained in detail. Next, specifications of accelerometers, location of accelerometers and optimization of accelerometer networks have been elaborated with respect to the geometry of the heritage structures. In addition to this, ambient vibration loads and data acquisition procedures are also discussed. Further, the state of art of performing OMA techniques for heritage structures is explained briefly. Furthermore, various applications of system identification for heritage structures are documented. Finally, conclusions are made towards errorless system identification of heritage structures through AVT and OMA.

Research paper thumbnail of Present Day Status and Numerical Modeling of Heritage Masonry Bridges of Kalka-Shimla Mountain Railways

International Journal of Masonry Research and Innovation

Research paper thumbnail of Effect of Layer Thickness and FRP Reinforcement Ratio on the Load Carrying Capacity of ECC Composite Beams

Composites science and technology, 2023

Research paper thumbnail of Seismic Vulnerability Assessment of Multi-arch Gallery Masonry Bridges Adopting Different Seismic Analysis Procedures

Research Square (Research Square), Oct 17, 2022

India has one of the longest rail networks all over the world. The Indian railway network consist... more India has one of the longest rail networks all over the world. The Indian railway network consist of many heritage bridges which are still in service over span of 100 years. Some of these heritage bridges are located in the very high seismic zone which is threat to their structural integrity. Therefore, it is necessary to assess the performance of these bridges for the earthquake loading. For this purpose, this paper attempts to predict the seismic vulnerability of the two multi arch gallery bridges of UNESCO recognised Kalka Shimla Mountain Railway. In this paper, three dimensional numerical models of the bridges were developed in ABAQUS finite element environment. The macro-modelling strategy was followed along with the concrete damage plasticity model as constitutive model for stone masonry. Further, the seismic performance of the bridges was estimated by nonlinear static analysis and incremental dynamic analysis procedures. The nonlinear static analysis was performed adopting two lateral loading patterns and incremental dynamic analysis was performed using 30 accelerograms. The 30 accelerograms were matched with the site-specific spectra and then scaled to different level of peak ground acceleration. The results from the nonlinear static analysis and incremental dynamic analysis were presented in terms of control node displacement and location of tensile damages. Lastly, the comparison between nonlinear static analysis results and incremental dynamic analysis results were showed that confirms, incremental dynamic analysis results are more significant at very high computational time consumption.

Research paper thumbnail of Effect of ECC layer thickness and reinforcement ratio on the load carrying capacity of steel‐reinforced composite beams

Structural Concrete

The present study investigates the effect of Engineered Cementitious Composites (ECC) layer thick... more The present study investigates the effect of Engineered Cementitious Composites (ECC) layer thickness against various reinforcement ratios on the flexural performance of reinforced ECC–concrete composite beams. In total, 20 reinforced composite beams are selected from the literature to predict their flexural response using Finite Element (FE) analysis. In addition to the FE analyses, a detailed analytical study is performed using the strain compatibility procedure to predict the flexural strength of ECC–concrete composite beams. The results from the FE analyses are compared against the experimental results and are found to show a close agreement. Using the validated FE models, detailed parametric studies are conducted to determine the effectiveness of different design parameters such as (a) ECC height replacement for a reinforcement ratio, (b) reinforcement ratio for an ECC height replacement, and (c) adequate reinforcement ratio for effective strengthening. The results of the param...

Research paper thumbnail of Present day status and numerical modelling of heritage masonry bridges of Kalka-Shimla Mountain Railways

International journal of masonry research and innovation, 2022

Research paper thumbnail of Experimental Study on Flexural Behaviour of High Ductile Cementitious Composites

Research paper thumbnail of Modelos de Diseño Orientado a Tensión-deformación para Hormigón Flexible

Research paper thumbnail of Performance of ductile fibre-reinforced cementitious composite concrete frames under flexural loading

Proceedings of the ICE - Construction Materials, 2013

Results of an experimental study on flexural behaviour of steel-reinforced portal frames made of ... more Results of an experimental study on flexural behaviour of steel-reinforced portal frames made of ductile fibre-reinforced cementitious composite and concrete under static transverse bending are reported in this paper. A total of six half-scale frames were cast and tested. It was observed that the frames partially or fully made of ductile fibre-reinforced cementitious composite have about 21–37% higher load-carrying capacity than ordinary concrete frames. Moreover, frames completely made of ductile fibre-reinforced cementitious composite are shown to have 1·5–2 times more ductility than the control frame. The failure modes of ductile fibre-reinforced cementitious composite frames were very ductile with multiple microcracks and the general pattern was flexural tension. In addition to the frame specimens, ductile fibre-reinforced cementitious composite tensile coupons, compressive cylinders and concrete cubes were also cast and evaluated.

Research paper thumbnail of Performance of NSM-FRP RC beams in flexure and shear using locally developed CFRP rebars

International Journal of Sustainable Materials and Structural Systems, 2012

Research paper thumbnail of Micromechanics based design approach for understanding the behaviour of an ECC beam

ABSTRACT This paper deals with micromechanics based design approach for modeling the flexural beh... more ABSTRACT This paper deals with micromechanics based design approach for modeling the flexural behaviour of a steel reinforced Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) beam. First, micromechanical models were developed to evaluate the peak tensile strength and strain of PVA-ECC. Then, generalised stress-strain relationships were derived for both uni-axial tension and compression. Next, Stress block parameters, which are associated with respective stress-strain relationships, were derived. Finally, a model for evaluating the flexural capacity of an ECC beam was developed. The results obtained by testing the model were in agreement with other analytical results available in the literature. However, to confirm the flexural behaviour and develop a unified design approach more experimental investigations are needed. Generally, the yielding behaviour of structural steel provides the ductility to reinforced concrete structures over normal loadings. However, during earthquake excitation and heavy impact conditions structures undergo large deformations. To withstand such loads they need to have more ductility that is inherent. In this context, it is noteworthy that ductility of reinforcements prevents concrete from brittle cracking. However, ductility related concerns can be solved to a large extent by using ductile concrete materials such as Slurry Infiltrated Fibre Concrete (SIFCON), Slurry Infiltrated Mat Concrete (SIMCON) , Polyethylene Engineered Cementitious Composite (PE-ECC) and Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) in structural constructions.

Research paper thumbnail of Design Oriented Stress-Strain Models for Engineered Cementitious Composites

Revista de la construcción, 2016

Research paper thumbnail of Serviceability analysis and increased axle load performance of heritage arch gallery railway bridge

This investigation deals with the serviceability analysis and increased axle load performance of ... more This investigation deals with the serviceability analysis and increased axle load performance of Bridge No. 541 of UNESCO recognised Kalka Shimla Mountain Railways, which is a multi-storey arch gallery stone masonry bridge situated in the state of Himachal Pradesh, India. For this purpose, a finite element (FE) model was developed based on the drawings and reports available in Shimla Division, Northern Railways, India. Further, the results obtained from ambient vibration test (AVT) and operational modal analysis (OMA) is utilized to model update the initial FE model by modifying the mechanical properties of stone masonry. The serviceability against present-day axle loading (H Class Loading, Indian Railways) and present speed of the train is assessed. At last, a parametric study is conducted to understand the feasibility to attain higher speeds (up to 40 kmph) of the present axle load and higher axle load with different speeds of the train over the bridge to check the serviceabilit...

Research paper thumbnail of Seismic vulnerability assessment and fragility curves for a multistorey gallery arch bridge

SN Applied Sciences

The masonry bridges on the Kalka Shimla Mountain Railway line, which have multiple arch galleries... more The masonry bridges on the Kalka Shimla Mountain Railway line, which have multiple arch galleries in the form of Roman aqueducts, are spectacular. The Kalka Shimla Mountain Railway line is situated in severe seismic zones (Indian Standard 1893:2016). This research assesses the seismic vulnerability of masonry arch Bridge No. 541 situated on the Kalka Shimla Mountain Railway line. This bridge is the tallest on the route. In particular, it assesses the seismic vulnerability of the bridge using finite element (FE) analysis. For this purpose, an FE model for the bridge is developed using the ABAQUS FE-based environment. The experimental field study conducted on the bridge using an ambient vibration test (AVT) and dynamic parameters (frequency and mode shapes) is evaluated by operational modal analysis (OMA). Further, the FE model is updated by modifying the elastic mechanical property of the stone masonry to match the analytical modal frequency with the results of the AVT and OMA. The u...

Research paper thumbnail of System Identification of Heritage Structures through AVT and OMA: A Review

Structural Durability & Health Monitoring

In this review article, the past investigations carried out on heritage structures using Ambient ... more In this review article, the past investigations carried out on heritage structures using Ambient Vibration Test (AVT) and Operational Modal Analysis (OMA) for system identification (determination of dynamic properties like frequency, mode shape and damping ratios) and associated applications are summarized. A total of 68 major research studies on heritage structures around the world that are available in literature are surveyed for this purpose. At first, field investigations carried out on heritage structures prior to conducting AVT are explained in detail. Next, specifications of accelerometers, location of accelerometers and optimization of accelerometer networks have been elaborated with respect to the geometry of the heritage structures. In addition to this, ambient vibration loads and data acquisition procedures are also discussed. Further, the state of art of performing OMA techniques for heritage structures is explained briefly. Furthermore, various applications of system identification for heritage structures are documented. Finally, conclusions are made towards errorless system identification of heritage structures through AVT and OMA.

Research paper thumbnail of System Identification of Heritage Structures through AVT and OMA: A Review

Structural Durability & Health Monitoring, 2019

In this review article, the past investigations carried out on heritage structures using Ambient ... more In this review article, the past investigations carried out on heritage structures using Ambient Vibration Test (AVT) and Operational Modal Analysis (OMA) for system identification (determination of dynamic properties like frequency, mode shape and damping ratios) and associated applications are summarized. A total of 68 major research studies on heritage structures around the world that are available in literature are surveyed for this purpose. At first, field investigations carried out on heritage structures prior to conducting AVT are explained in detail. Next, specifications of accelerometers, location of accelerometers and optimization of accelerometer networks have been elaborated with respect to the geometry of the heritage structures. In addition to this, ambient vibration loads and data acquisition procedures are also discussed. Further, the state of art of performing OMA techniques for heritage structures is explained briefly. Furthermore, various applications of system identification for heritage structures are documented. Finally, conclusions are made towards errorless system identification of heritage structures through AVT and OMA.

Research paper thumbnail of Present Day Status and Numerical Modeling of Heritage Masonry Bridges of Kalka-Shimla Mountain Railways

International Journal of Masonry Research and Innovation