Amba Bhatt - Academia.edu (original) (raw)
Papers by Amba Bhatt
Biomechanics and Modeling in Mechanobiology
This article presents the investigations on modified mechanical and wear characteristics of cemen... more This article presents the investigations on modified mechanical and wear characteristics of cement kiln dust (CKD) reinforced homogeneous epoxy composites and its
Computer-Aided Design and Applications, 2016
The photogrammetry procedure is introduced as a cheap and-effective alternative to 3D scanning fo... more The photogrammetry procedure is introduced as a cheap and-effective alternative to 3D scanning for constructing 3D point cloud data for reverse engineering applications. The data is then manipulated to generate CAD-ready models for FEA simulations or 3D printing purposes. A practical demonstration using model cars is conducted to show the effectiveness of the procedure in generating point cloud data, and various improvements are introduced. In particular, and innovative to this research work, a feature segmentation algorithm based on color information captured from photographs is implemented. This program, embedded within the photogrammetry process, allows for automatic selection of parts and features from an assembly model, providing a leading advantage over current 3D scanners, which capture spatial data only. Moreover, an intuitive method of enhancing the selection of required features of a triangular mesh during the segmentation process is introduced. This is achieved by manually marking the boundaries on the part of the object to be selected prior to taking photos. This has been proved to be more effective where areas of the object parts have similar colors.
Rapid Prototyping Journal, 2002
Solid modeling of objects forms an important task in design and manufacturing. Recent development... more Solid modeling of objects forms an important task in design and manufacturing. Recent developments in the field of layered manufacturing (LM) have shown potential for the physical realization of heterogeneous (multi-material) objects. Thus, there is a need to represent material information as an integral part of the CAD model data. Slicing of the CAD model is an inherent part of process planning for LM. There is a need for a neutral 2D slice format to transfer data from the CAD system (slicing is done on the 3D CAD model) to the commercial LM machine. This can also be used as a file format to demonstrate inter-operability among LM machines having comparable layer thickness specifications. To fabricate heterogeneous objects, the slice format should be capable of representing both material and geometry information. Information models for the representation of product data are being developed as an international standard (ISO 10303) informally called STEP. However, the current application protocols focus on the representation of homogeneous objects only. This paper suggests an information model to represent heterogeneous objects using the information modeling methodology developed for ISO 10303. The information model
Computer-Aided Design and Applications, 2008
Human body is a natural heterogeneous object optimized in its structure and composition by natura... more Human body is a natural heterogeneous object optimized in its structure and composition by natural processes over the years of evolution. In this paper, B-spline surface representation method is extended to represent material composition for the development of heterogeneous human body model. Two different approaches namely surface fairing and surface fit are used to create slice by slice model from CT scan data. Both the approaches are compared for different regression parameters. This methodology has potential to represent body internal details accurately with fewer digital input data and is extendable to 3-D solid modeling of human body with applications in FEM analysis, freeform-fabrication and tissue engineering.
Engineering with Computers, 2022
Materials Today: Proceedings, 2021
Materials Science: An Indian Journal, 2009
Functionally Graded materials (FGM) are multifunctional materials which are used to produce compo... more Functionally Graded materials (FGM) are multifunctional materials which are used to produce components that require functional performance which is variable within the component and this functional performance is achieved bymanipulating the composition either atmicrometer level or at nanolevel. This is basically termed as engineering the transition inmicro/nanostructure. This in fact enhances the overall performance of the component. These materials are currently in the forefront of material research. Numerous techniques have been proposed in the last two decades and practically exercised for manufacturing of FGMs. This article presents a comprehensive deliberation of powder based manufacturing techniques which have been employed by the researchers throughout the globe for successful fabrication of an FGM. Attempt is made to throw light on practical applications of FGMand on fewimportant issueswhile attempting for FGM synthesis. The work reviewed in this paper is mostly confined to ...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2021
Porous scaffolds assisted bone tissue engineering is a viable alternative for reconstruction of l... more Porous scaffolds assisted bone tissue engineering is a viable alternative for reconstruction of large segmental bone defects caused by bone pathologies or trauma. In the current study, we intend to develop trabecular bone scaffolds using gyroid architecture. An interactive modeling framework is developed for the design of three-dimensional gyroid scaffolds using advanced generative tools including K3DSurf, MeshLab, and Netfabb. The suggested modeling approach resulted in uniform and interconnected pores. Subsequently, fused deposition modeling 3D-printing is employed to fabricate the scaffolds using poly lactic acid material. The pores interconnectivity, porosity, and surface finish of the fabricated scaffolds are characterized using micro-computer tomography and scanning electron microscopy. Additionally, to assess the performance of scaffolds as a bone substitute, compression, and in-vitro biocompatibility tests on sterilized scaffolds are conducted. Compression tests reveal mecha...
Manufacturing Engineering, 2000
Solid modeling of objects forms an important task in design and manufacturing. Recent development... more Solid modeling of objects forms an important task in design and manufacturing. Recent developments in the field of layered manufacturing have shown potential for the physical realization of heterogeneous (multi-material) objects. Thus, there is a need to represent material information as an integral part of the CAD model data. Information models for the representation of product data are being developed as an international standard called STEP (ISO 10303). However, the current application protocols focus on the representation of homogeneous objects only. This paper proposes an information model to represent heterogeneous objects using the information modeling methodology developed for ISO 10303. This will help in providing a uniform base in the development of heterogeneous solid modeling systems. It will also equip the solid modeler with the ability to integrate with other applications and process planning in the domain of layered manufacturing.
Journal of Applied Fluid Mechanics, 2014
Journal of Materials Engineering and Performance, 2019
Regeneration or repairing an injured tissue using porous scaffolds, to rehabilitate the mechanica... more Regeneration or repairing an injured tissue using porous scaffolds, to rehabilitate the mechanical, biological and chemical actions, is one of the better options available, for tissue engineering and trauma cure. In this work, the nature-inspired gyroid architecture is selected for design of porous scaffolds. Implicit-function-based modeling is performed to understand the basic geometric characteristics of this complex architecture. A study on the effect of tuning the offset parameter (t) used in the gyroid equation, on the scaffold porosity and specific surface area, is carried out. Further, gyroid scaffolds with varying porosities and interconnected pores are modeled and subsequently manufactured using the fused deposition modeling (FDM) additive manufacturing (AM) technique, with polylactic acid (PLA) filaments. Results show that the function-based gyroid modeling is ideally suited for the design and AM of continuous porous scaffolds. Compression test is also conducted on AMed scaffolds to examine their load bearing ability. Tests reveal that the porous scaffolds have compressive strength equivalent of that of the human trabecular bone. Additionally, this study investigated in vitro, the cell viability of PLA gyroid scaffolds by measuring the cell proliferation after 48 and 72 h showing expected biocompatibility. In conclusion, the FDM manufactured gyroid scaffolds seem to be a viable alternative for bone tissue engineering applications.
Proceedings of CAD'19, 2019
Computer-Aided Design and Applications, 2018
Computer-Aided Design and Applications
Recent advances in design technique and material processing have allowed manufacturing a wide var... more Recent advances in design technique and material processing have allowed manufacturing a wide variety of heterogeneous (functionally graded) materials. A novel design and analysis approach based on B-spline representation with knot insertion technique for mesh refinement has been presented here. To improve the performance of analysis knot insertion technique has been applied at the region of interest with Lagrangian graded element. The distinct advantages of this technique are true material-geometry representation and inherent mesh construction and its refinement.
Flat pattern nesting problems are optimization problems that are concerned with finding a good ar... more Flat pattern nesting problems are optimization problems that are concerned with finding a good arrangement of multiple two dimensional objects on two-dimensional stock. This work deals with nesting of two-dimensional objects (regular and irregular, convex and non-convex) on two-dimensional rectangular stock. An approach is given in the present work for optimal layout of irregular two-dimensional objects using heuristic methods. It works by hierarchically decomposing original problem into many sub-problems. It is assumed that combining the solution of each sub-problem will yield a good result. First ranked the objects according to a sequencing policy and then placed the sequenced objects using bottom left placement heuristic. Finally, interactive nesting strategy is used to get closed and compact nesting (better solution) on results obtained by automatic nesting. The algorithm for placement matches concavities and convexities existing in objects and defines a best-fit adjacent object...
Biomechanics and Modeling in Mechanobiology
This article presents the investigations on modified mechanical and wear characteristics of cemen... more This article presents the investigations on modified mechanical and wear characteristics of cement kiln dust (CKD) reinforced homogeneous epoxy composites and its
Computer-Aided Design and Applications, 2016
The photogrammetry procedure is introduced as a cheap and-effective alternative to 3D scanning fo... more The photogrammetry procedure is introduced as a cheap and-effective alternative to 3D scanning for constructing 3D point cloud data for reverse engineering applications. The data is then manipulated to generate CAD-ready models for FEA simulations or 3D printing purposes. A practical demonstration using model cars is conducted to show the effectiveness of the procedure in generating point cloud data, and various improvements are introduced. In particular, and innovative to this research work, a feature segmentation algorithm based on color information captured from photographs is implemented. This program, embedded within the photogrammetry process, allows for automatic selection of parts and features from an assembly model, providing a leading advantage over current 3D scanners, which capture spatial data only. Moreover, an intuitive method of enhancing the selection of required features of a triangular mesh during the segmentation process is introduced. This is achieved by manually marking the boundaries on the part of the object to be selected prior to taking photos. This has been proved to be more effective where areas of the object parts have similar colors.
Rapid Prototyping Journal, 2002
Solid modeling of objects forms an important task in design and manufacturing. Recent development... more Solid modeling of objects forms an important task in design and manufacturing. Recent developments in the field of layered manufacturing (LM) have shown potential for the physical realization of heterogeneous (multi-material) objects. Thus, there is a need to represent material information as an integral part of the CAD model data. Slicing of the CAD model is an inherent part of process planning for LM. There is a need for a neutral 2D slice format to transfer data from the CAD system (slicing is done on the 3D CAD model) to the commercial LM machine. This can also be used as a file format to demonstrate inter-operability among LM machines having comparable layer thickness specifications. To fabricate heterogeneous objects, the slice format should be capable of representing both material and geometry information. Information models for the representation of product data are being developed as an international standard (ISO 10303) informally called STEP. However, the current application protocols focus on the representation of homogeneous objects only. This paper suggests an information model to represent heterogeneous objects using the information modeling methodology developed for ISO 10303. The information model
Computer-Aided Design and Applications, 2008
Human body is a natural heterogeneous object optimized in its structure and composition by natura... more Human body is a natural heterogeneous object optimized in its structure and composition by natural processes over the years of evolution. In this paper, B-spline surface representation method is extended to represent material composition for the development of heterogeneous human body model. Two different approaches namely surface fairing and surface fit are used to create slice by slice model from CT scan data. Both the approaches are compared for different regression parameters. This methodology has potential to represent body internal details accurately with fewer digital input data and is extendable to 3-D solid modeling of human body with applications in FEM analysis, freeform-fabrication and tissue engineering.
Engineering with Computers, 2022
Materials Today: Proceedings, 2021
Materials Science: An Indian Journal, 2009
Functionally Graded materials (FGM) are multifunctional materials which are used to produce compo... more Functionally Graded materials (FGM) are multifunctional materials which are used to produce components that require functional performance which is variable within the component and this functional performance is achieved bymanipulating the composition either atmicrometer level or at nanolevel. This is basically termed as engineering the transition inmicro/nanostructure. This in fact enhances the overall performance of the component. These materials are currently in the forefront of material research. Numerous techniques have been proposed in the last two decades and practically exercised for manufacturing of FGMs. This article presents a comprehensive deliberation of powder based manufacturing techniques which have been employed by the researchers throughout the globe for successful fabrication of an FGM. Attempt is made to throw light on practical applications of FGMand on fewimportant issueswhile attempting for FGM synthesis. The work reviewed in this paper is mostly confined to ...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2021
Porous scaffolds assisted bone tissue engineering is a viable alternative for reconstruction of l... more Porous scaffolds assisted bone tissue engineering is a viable alternative for reconstruction of large segmental bone defects caused by bone pathologies or trauma. In the current study, we intend to develop trabecular bone scaffolds using gyroid architecture. An interactive modeling framework is developed for the design of three-dimensional gyroid scaffolds using advanced generative tools including K3DSurf, MeshLab, and Netfabb. The suggested modeling approach resulted in uniform and interconnected pores. Subsequently, fused deposition modeling 3D-printing is employed to fabricate the scaffolds using poly lactic acid material. The pores interconnectivity, porosity, and surface finish of the fabricated scaffolds are characterized using micro-computer tomography and scanning electron microscopy. Additionally, to assess the performance of scaffolds as a bone substitute, compression, and in-vitro biocompatibility tests on sterilized scaffolds are conducted. Compression tests reveal mecha...
Manufacturing Engineering, 2000
Solid modeling of objects forms an important task in design and manufacturing. Recent development... more Solid modeling of objects forms an important task in design and manufacturing. Recent developments in the field of layered manufacturing have shown potential for the physical realization of heterogeneous (multi-material) objects. Thus, there is a need to represent material information as an integral part of the CAD model data. Information models for the representation of product data are being developed as an international standard called STEP (ISO 10303). However, the current application protocols focus on the representation of homogeneous objects only. This paper proposes an information model to represent heterogeneous objects using the information modeling methodology developed for ISO 10303. This will help in providing a uniform base in the development of heterogeneous solid modeling systems. It will also equip the solid modeler with the ability to integrate with other applications and process planning in the domain of layered manufacturing.
Journal of Applied Fluid Mechanics, 2014
Journal of Materials Engineering and Performance, 2019
Regeneration or repairing an injured tissue using porous scaffolds, to rehabilitate the mechanica... more Regeneration or repairing an injured tissue using porous scaffolds, to rehabilitate the mechanical, biological and chemical actions, is one of the better options available, for tissue engineering and trauma cure. In this work, the nature-inspired gyroid architecture is selected for design of porous scaffolds. Implicit-function-based modeling is performed to understand the basic geometric characteristics of this complex architecture. A study on the effect of tuning the offset parameter (t) used in the gyroid equation, on the scaffold porosity and specific surface area, is carried out. Further, gyroid scaffolds with varying porosities and interconnected pores are modeled and subsequently manufactured using the fused deposition modeling (FDM) additive manufacturing (AM) technique, with polylactic acid (PLA) filaments. Results show that the function-based gyroid modeling is ideally suited for the design and AM of continuous porous scaffolds. Compression test is also conducted on AMed scaffolds to examine their load bearing ability. Tests reveal that the porous scaffolds have compressive strength equivalent of that of the human trabecular bone. Additionally, this study investigated in vitro, the cell viability of PLA gyroid scaffolds by measuring the cell proliferation after 48 and 72 h showing expected biocompatibility. In conclusion, the FDM manufactured gyroid scaffolds seem to be a viable alternative for bone tissue engineering applications.
Proceedings of CAD'19, 2019
Computer-Aided Design and Applications, 2018
Computer-Aided Design and Applications
Recent advances in design technique and material processing have allowed manufacturing a wide var... more Recent advances in design technique and material processing have allowed manufacturing a wide variety of heterogeneous (functionally graded) materials. A novel design and analysis approach based on B-spline representation with knot insertion technique for mesh refinement has been presented here. To improve the performance of analysis knot insertion technique has been applied at the region of interest with Lagrangian graded element. The distinct advantages of this technique are true material-geometry representation and inherent mesh construction and its refinement.
Flat pattern nesting problems are optimization problems that are concerned with finding a good ar... more Flat pattern nesting problems are optimization problems that are concerned with finding a good arrangement of multiple two dimensional objects on two-dimensional stock. This work deals with nesting of two-dimensional objects (regular and irregular, convex and non-convex) on two-dimensional rectangular stock. An approach is given in the present work for optimal layout of irregular two-dimensional objects using heuristic methods. It works by hierarchically decomposing original problem into many sub-problems. It is assumed that combining the solution of each sub-problem will yield a good result. First ranked the objects according to a sequencing policy and then placed the sequenced objects using bottom left placement heuristic. Finally, interactive nesting strategy is used to get closed and compact nesting (better solution) on results obtained by automatic nesting. The algorithm for placement matches concavities and convexities existing in objects and defines a best-fit adjacent object...