Monel alloys containing 63Ni–30Cu (wt%) are often used in applications requiring simultaneously h... more Monel alloys containing 63Ni–30Cu (wt%) are often used in applications requiring simultaneously high strength and corrosion resistance. Additions of Ti, Al and C to Monel K500 lead to formation of TiC, Ni3Al and Ni3Ti particles, which provide precipitation strengthening effect following heat treatment. The traditional heat treatment schedule includes solution annealing above 1000 °C and aging in the 400–600 °C temperature range. However, no correlation exists between the alloy composition and the heat treatment schedule (holding temperature and time) required to obtain the optimum microstructure and mechanical properties. This may result in excessive alloying, energy loses during heat treatment, and higher product costs. In this work, we investigate the effect of solution annealing part of heat treatment schedule on microstructure (particularly, particle precipitation and grain growth), hardness and strength. For hot rolled samples, solution annealing followed by aging was shown to ...
Volume 3: Materials Technology; Pipelines, Risers, and Subsea Systems
The fabrication of ship hulls involves welding operations, one typical operation is fillet weldin... more The fabrication of ship hulls involves welding operations, one typical operation is fillet welding of stiffeners to plates (panels) a so-called T-joint. The residual stresses from the welding process will influence the fatigue life of the structure, and residual deformations will increase the risk for buckling of the panel and give poor fabrication tolerances which may complicate the assembly of a built-up structure. Though this weld geometry has been frequently studied in the literature both experimentally and numerically, the focus has been on the residual stress field and if residual deformations are studied, the angular distortion and the typical V-shape seen in the welded plate (panel) are reported. This benchmark focusses on the residual shape after two-pass fillet welding of a stiffener to a plate (T-joint and the influence of the constraints used during welding. The information of the full welding residual deformations may be useful for the fabrication of larger complex weld...
An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting pr... more An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting productivity and safety on underground coal continuous miners by replacing steel mesh, and has broader applications as surface support and confinement in metalliferous mines and civil tunnelling. Polymer chemistry, coating formulation, geotechnical assessment and the autonomous application system are being developed within an integrated package as part of a continuous miner automation project. The polymer-based TSL system, dubbed "ToughSkin", has significant benefits over conventional steel mesh, including; more automatable by spray application, complete skin confinement, active skin reinforcement as a fast-curing composite with substrate, and effective fire retardant for the polymer and underlying coal. This paper investigates distance sensing systems that will enable an autonomous manipulator to adapt nominal spray path standoff distance and application angles in order to spray...
Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic ov... more Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic overhangs without support structures through multi-direction deposition. To automatically produce complex components with overhangs, an efficient multi-direction slicing algorithm to slice CAD models into a set of proper layers is required. This paper reports the concept and implementation of a new strategy for multi-direction slicing of CAD models represented in STL format. An input STL model is firstly decomposed into sub-volumes using a simple curvaturebased volume decomposition method. Accordingly, each sub-volume is able to be built in a single direction. Then a depth-tree structure is introduced to regroup the decomposed sub-volumes and provide the slicing sequences. Consequently, sub-volumes are separately sliced along their associated appropriate build directions in sequence. The proposed multi-direction slicing strategy is shown to be simple and efficient for STL models with sharp edges.
An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting pr... more An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting productivity and safety on underground coal continuous miners by replacing steel mesh, and has broader applications as surface support and confinement in metalliferous mines and civil tunnelling. Polymer chemistry, coating formulation, geotechnical assessment and the autonomous application system are being developed within an integrated package as part of a continuous miner automation project. The polymer-based TSL system, dubbed "ToughSkin", has significant benefits over conventional steel mesh, including; more automatable by spray application, complete skin confinement, active skin reinforcement as a fast-curing composite with substrate, and effective fire retardant for the polymer and underlying coal. This paper investigates distance sensing systems that will enable an autonomous manipulator to adapt nominal spray path standoff distance and application angles in order to spray...
Although robotics based flexible automation is an intriguing prospect for small to median enterpr... more Although robotics based flexible automation is an intriguing prospect for small to median enterprises in the era of the global competition, the complexity of programming remains one of the major hurdles limiting its applications. This paper presents an automated offline programming (AOLP) method to address this issue. AOLP is software that automatically plans and programs for a robotic welding system with high Degree of Freedoms (DOFs). It takes CAD model as input, and is able to generate the complete robotic welding code without any further programming effort.
Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic ov... more Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic overhangs without support structures through multi-direction deposition. To automatically produce complex components with overhangs, an efficient multi-direction slicing algorithm to slice CAD models into a set of proper layers is required. This paper reports the concept and implementation of a new strategy for multi-direction slicing of CAD models represented in STL format. An input STL model is firstly decomposed into sub-volumes using a simple curvaturebased volume decomposition method. Accordingly, each sub-volume is able to be built in a single direction. Then a depth-tree structure is introduced to regroup the decomposed sub-volumes and provide the slicing sequences. Consequently, sub-volumes are separately sliced along their associated appropriate build directions in sequence. The proposed multi-direction slicing strategy is shown to be simple and efficient for STL models with sharp edges.
Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps du... more Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.
Although robotics based flexible automation is an intriguing prospect for small to median enterpr... more Although robotics based flexible automation is an intriguing prospect for small to median enterprises in the era of the global competition, the complexity of programming remains one of the major hurdles limiting its applications. This paper presents an automated offline programming (AOLP) method to address this issue. AOLP is software that automatically plans and programs for a robotic welding system with high Degree of Freedoms (DOFs). It takes CAD model as input, and is able to generate the complete robotic welding code without any further programming effort.
Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps du... more Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.
Robotics and Computer-Integrated Manufacturing, 2012
"Although an automated flexible production cell is an intriguing prospect for small to median ent... more "Although an automated flexible production cell is an intriguing prospect for small to median enterprises (SMEs) in current global market conditions, the complexity of programming remains one of the major hurdles preventing automation using industrial robots for SMEs. This paper provides a comprehensive review of the recent research progresses on the programming methods for industrial robots, including online programming, offline programming (OLP), and programming using Augmented Reality (AR). With the development of more powerful 3D CAD/PLM software, computer vision, sensor technology, etc. new programming methods suitable for SMEs are expected to grow in years to come.
The feasibility of using Tandem Gas Metal Arc Welding (T-GMAW) to produce full penetration butt w... more The feasibility of using Tandem Gas Metal Arc Welding (T-GMAW) to produce full penetration butt welds in 5mm ship panel steel plates has been assessed and compared to the current Submerged Arc Welding (SAW) process. Experiments conducted show that the T-GMAW process is feasible and demonstrated a significant improvement over the SAW process in several areas including higher travel speed, a reduction in filler material, significantly lower post weld distortion, and a smaller Heat Affected Zone (HAZ), while maintaining similar microstructure and mechanical properties in the weld metal and HAZ.
This paper presents an offline programming (OLP) system for a complex robotic welding cell using ... more This paper presents an offline programming (OLP) system for a complex robotic welding cell using DELMIA Automation. The goals of this research are aimed at investigating the feasibility of taking a commercially available robotic simulation package, DELMIA, and to use a Visual Basic Automation interface to reduce the programming time by creating automated 'modules' to carry out some of the tasks in the OLP process. The paper first investigates and presents the structure of OLP as a discreet method of individual steps. These steps are then evaluated for their potential as an automation candidate. The methods in which these steps are automated are then presented. A general analysis of the developed OLP system was carried out, providing a scope for future research and development
Monel alloys containing 63Ni–30Cu (wt%) are often used in applications requiring simultaneously h... more Monel alloys containing 63Ni–30Cu (wt%) are often used in applications requiring simultaneously high strength and corrosion resistance. Additions of Ti, Al and C to Monel K500 lead to formation of TiC, Ni3Al and Ni3Ti particles, which provide precipitation strengthening effect following heat treatment. The traditional heat treatment schedule includes solution annealing above 1000 °C and aging in the 400–600 °C temperature range. However, no correlation exists between the alloy composition and the heat treatment schedule (holding temperature and time) required to obtain the optimum microstructure and mechanical properties. This may result in excessive alloying, energy loses during heat treatment, and higher product costs. In this work, we investigate the effect of solution annealing part of heat treatment schedule on microstructure (particularly, particle precipitation and grain growth), hardness and strength. For hot rolled samples, solution annealing followed by aging was shown to ...
Volume 3: Materials Technology; Pipelines, Risers, and Subsea Systems
The fabrication of ship hulls involves welding operations, one typical operation is fillet weldin... more The fabrication of ship hulls involves welding operations, one typical operation is fillet welding of stiffeners to plates (panels) a so-called T-joint. The residual stresses from the welding process will influence the fatigue life of the structure, and residual deformations will increase the risk for buckling of the panel and give poor fabrication tolerances which may complicate the assembly of a built-up structure. Though this weld geometry has been frequently studied in the literature both experimentally and numerically, the focus has been on the residual stress field and if residual deformations are studied, the angular distortion and the typical V-shape seen in the welded plate (panel) are reported. This benchmark focusses on the residual shape after two-pass fillet welding of a stiffener to a plate (T-joint and the influence of the constraints used during welding. The information of the full welding residual deformations may be useful for the fabrication of larger complex weld...
An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting pr... more An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting productivity and safety on underground coal continuous miners by replacing steel mesh, and has broader applications as surface support and confinement in metalliferous mines and civil tunnelling. Polymer chemistry, coating formulation, geotechnical assessment and the autonomous application system are being developed within an integrated package as part of a continuous miner automation project. The polymer-based TSL system, dubbed "ToughSkin", has significant benefits over conventional steel mesh, including; more automatable by spray application, complete skin confinement, active skin reinforcement as a fast-curing composite with substrate, and effective fire retardant for the polymer and underlying coal. This paper investigates distance sensing systems that will enable an autonomous manipulator to adapt nominal spray path standoff distance and application angles in order to spray...
Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic ov... more Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic overhangs without support structures through multi-direction deposition. To automatically produce complex components with overhangs, an efficient multi-direction slicing algorithm to slice CAD models into a set of proper layers is required. This paper reports the concept and implementation of a new strategy for multi-direction slicing of CAD models represented in STL format. An input STL model is firstly decomposed into sub-volumes using a simple curvaturebased volume decomposition method. Accordingly, each sub-volume is able to be built in a single direction. Then a depth-tree structure is introduced to regroup the decomposed sub-volumes and provide the slicing sequences. Consequently, sub-volumes are separately sliced along their associated appropriate build directions in sequence. The proposed multi-direction slicing strategy is shown to be simple and efficient for STL models with sharp edges.
An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting pr... more An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting productivity and safety on underground coal continuous miners by replacing steel mesh, and has broader applications as surface support and confinement in metalliferous mines and civil tunnelling. Polymer chemistry, coating formulation, geotechnical assessment and the autonomous application system are being developed within an integrated package as part of a continuous miner automation project. The polymer-based TSL system, dubbed "ToughSkin", has significant benefits over conventional steel mesh, including; more automatable by spray application, complete skin confinement, active skin reinforcement as a fast-curing composite with substrate, and effective fire retardant for the polymer and underlying coal. This paper investigates distance sensing systems that will enable an autonomous manipulator to adapt nominal spray path standoff distance and application angles in order to spray...
Although robotics based flexible automation is an intriguing prospect for small to median enterpr... more Although robotics based flexible automation is an intriguing prospect for small to median enterprises in the era of the global competition, the complexity of programming remains one of the major hurdles limiting its applications. This paper presents an automated offline programming (AOLP) method to address this issue. AOLP is software that automatically plans and programs for a robotic welding system with high Degree of Freedoms (DOFs). It takes CAD model as input, and is able to generate the complete robotic welding code without any further programming effort.
Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic ov... more Robotic wire-feed additive manufacturing technology is possible to directly fabricate metallic overhangs without support structures through multi-direction deposition. To automatically produce complex components with overhangs, an efficient multi-direction slicing algorithm to slice CAD models into a set of proper layers is required. This paper reports the concept and implementation of a new strategy for multi-direction slicing of CAD models represented in STL format. An input STL model is firstly decomposed into sub-volumes using a simple curvaturebased volume decomposition method. Accordingly, each sub-volume is able to be built in a single direction. Then a depth-tree structure is introduced to regroup the decomposed sub-volumes and provide the slicing sequences. Consequently, sub-volumes are separately sliced along their associated appropriate build directions in sequence. The proposed multi-direction slicing strategy is shown to be simple and efficient for STL models with sharp edges.
Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps du... more Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.
Although robotics based flexible automation is an intriguing prospect for small to median enterpr... more Although robotics based flexible automation is an intriguing prospect for small to median enterprises in the era of the global competition, the complexity of programming remains one of the major hurdles limiting its applications. This paper presents an automated offline programming (AOLP) method to address this issue. AOLP is software that automatically plans and programs for a robotic welding system with high Degree of Freedoms (DOFs). It takes CAD model as input, and is able to generate the complete robotic welding code without any further programming effort.
Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps du... more Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.
Robotics and Computer-Integrated Manufacturing, 2012
"Although an automated flexible production cell is an intriguing prospect for small to median ent... more "Although an automated flexible production cell is an intriguing prospect for small to median enterprises (SMEs) in current global market conditions, the complexity of programming remains one of the major hurdles preventing automation using industrial robots for SMEs. This paper provides a comprehensive review of the recent research progresses on the programming methods for industrial robots, including online programming, offline programming (OLP), and programming using Augmented Reality (AR). With the development of more powerful 3D CAD/PLM software, computer vision, sensor technology, etc. new programming methods suitable for SMEs are expected to grow in years to come.
The feasibility of using Tandem Gas Metal Arc Welding (T-GMAW) to produce full penetration butt w... more The feasibility of using Tandem Gas Metal Arc Welding (T-GMAW) to produce full penetration butt welds in 5mm ship panel steel plates has been assessed and compared to the current Submerged Arc Welding (SAW) process. Experiments conducted show that the T-GMAW process is feasible and demonstrated a significant improvement over the SAW process in several areas including higher travel speed, a reduction in filler material, significantly lower post weld distortion, and a smaller Heat Affected Zone (HAZ), while maintaining similar microstructure and mechanical properties in the weld metal and HAZ.
This paper presents an offline programming (OLP) system for a complex robotic welding cell using ... more This paper presents an offline programming (OLP) system for a complex robotic welding cell using DELMIA Automation. The goals of this research are aimed at investigating the feasibility of taking a commercially available robotic simulation package, DELMIA, and to use a Visual Basic Automation interface to reduce the programming time by creating automated 'modules' to carry out some of the tasks in the OLP process. The paper first investigates and presents the structure of OLP as a discreet method of individual steps. These steps are then evaluated for their potential as an automation candidate. The methods in which these steps are automated are then presented. A general analysis of the developed OLP system was carried out, providing a scope for future research and development
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Papers by S. Van Duin