Browsing by Author "Von Klemperer, Christopher"

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    Novel, low-cost, CFRP pressure vessel design for hydrogen fuel cell applications
    (2019) Mawire, Nyasha Nigel; Von Klemperer, Christopher
    In 2015, the Ascension III water rocket shattered the previous long-standing world record of 633 m after reaching an altitude of 835 m. This feat was primarily attributed to the design of the Carbon Fibre Reinforced Plastic (CFRP) pressure vessel portion of the rocket. The pressure vessel was composed on a long, thin-walled commercial CFRP cylindrical tube that had two Poly Vinyl Chloride (PVC) end caps bonded onto either end with an adhesive. The inside wall of the CFRP tube was coated with a thin rubber liner to prevent leakage through the tube wall of the pressurised air-water mixture that provided the necessary thrust for the rocket. The outcome was that the CFRP pressure vessel design was thus, novel, low-cost and lightweight with the potential to be used in other gas storage applications for example in Hydrogen Fuel Cell (HFC) applications. This report details the research aimed at identifying the feasibility and suitability of the proposed CFRP pressure vessel concept for high pressure hydrogen gas storage for use in Hydrogen Fuel Cell Powered Vehicles (HFCPVs). The primary component of the pressure vessel to be designed was the CFRP tube which was to be commercially filament wound using carbon fibre and epoxy resin. With an angle ply laminate structure for the CFRP tube, an optimal fibre winding angle of 50° was initially chosen to maximise the burst pressure. The stress analysis and strain behaviour of the CFRP tube were modelled using the Classical Lamination Theory. Specimens were made using the same CFRP material as the tube and were tensile tested to give an initial set of approximate properties to be used in the design calculations. The distinct geometrical features of the end cap were designed, and Aluminium 6082-T6 was selected as a suitable material for its construction as it was easy to machine while it also possessed desirable mechanical properties. SpaBond 340 LV epoxy adhesive was used to bond the end caps onto the ends of the CFRP tube. A number of specimen CFRP pressure vessels were constructed with the inclusion of the rubber liner. Hydrostatic burst tests were performed on specimen vessels with different wall thicknesses (2 mm and 4 mm) to determine the pressure at which each type of vessel would fail. However, only the 2 mm vessels experienced failure of the CFRP tube section as the predominant failure mode while most 4 mm vessels failed by shearing of the interface between the adhesive layer and end cap. According to the ASME Boiler and Pressure Code Section X, the maximum design pressures at which the CFRP pressure vessels could operate at were at most, 2.25 times smaller than the respective failure pressures. The maximum design pressures were thus determined to be 147 bar and 182 bar for the 2 mm and 4 mm CFRP pressure vessels respectively. The specimen pressure vessels were also fitted with strain gauges on the external cylindrical surface of the CFRP tubes to measure the longitudinal and hoop strain during the burst tests. The strain measurements allowed the deformation behaviour of the CFRP tubes to be modelled which would prove useful for designing further CFRP tubes. For all specimen CFRP pressure vessels, it was observed that the deformation response of the CFRP tubes were linear up until a certain pressure. Beyond that point, a decrease in stiffness was observed which suggested that some form of irreparable damage had commenced. Other specimen CFRP pressure vessels were constructed and underwent hydraulic proof testing at 1.25 times the design pressure for 30 minutes and at the design pressure for a further 24 hours. The objective was to assess if the pressure vessels were durable and reliable of which all tested specimen vessels passed successfully. The hydraulic proof test results seemingly suggested that the rubber liner could adequately prevent leakage of water from the vessels at their design pressures. The long-term gas leak test was performed at the design pressure using air (i.e. a compressible fluid) on the proof tested pressure vessels to detect and localize any leaks for a duration of up to 72 hours. However, the leak rates were determined to be at least an order of magnitude larger than the recommended leak rate for hydrogen gas storage vessels. The leak test results strongly suggested that the rubber liner was insufficient to prevent air molecules from escaping the vessel, was not durable for repeated use and thus, not suitable for long-term gas storage. Therefore, it was concluded that the novel CFRP pressure vessel design concept was not yet suitable for hydrogen gas storage, but with improvements, could still prove possible for use in HFCPVs. Further work into these improvements could include improving the end cap design and testing other rubber liners.
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    Open Access
    Response of composite and steel V-structures to localised air blast loading - Numerical and Experimental
    (2023) Shekhar, Vinay; Von Klemperer, Christopher; Langdon Genevieve
    This research investigated the blast performance of Glass-Fibre Reinforced Polymer (GFRP) Vstructures compared to equivalent mass steel V-structures. The blast performance was measured in terms of three metrics, namely, impulse transferred, maximum mid-point deflection and permanent damage/deformation. A series of blast experiments were performed on manufactured GFRP and steel V-structures. The GFRP V-structures were made using Vacuum Infusion (VI), using a 400 g m−2 woven E-glass and a Prime 20LV resin with a Low Viscosity (LV) slow hardener. The steel V-structures were manufactured by laser cutting the flat panel profiles from a sheet of 2 mm thick DOMEX-700 MC sheet and then Computer Numerical Control (CNC) bending them to the desired profile. Three panel configurations were experimentally blast tested, namely, a 105° V-angle with a 32 mm V-tip radius, a 105° V-angle with a 62 mm V-tip radius and a 120° V-angle with a 32 mm V-tip radius. Blast tests were performed by detonating PE4 charges ranging from 10 g to 40 g at a Stand-Off Distance (SOD) of 34 mm. Digital Image Correlation (DIC) was used to track the transient deformation of the V-structures, while the final deformed profile of the V-structures was determined using a 3D scanner. A series of numerical simulations were also performed on the GFRP and steel V-structures. The simulations used quarter symmetry models to utilise the symmetry of the experimental setup. The material model parameters were obtained from a series of material tests carried out on GFRP and steel specimens. The simulations were validated against the experimental results for a number of test cases for impulse transfer, and transient and permanent deformation. The simulations were then extended to look at a range of V-tip radii, V-angles and charge masses, while the SOD was held constant. For the steel V-structures, the blast experiments found that increasing the V-tip radius and Vangle resulted in an increase in impulse transferred as well as transient and permanent mid-point deflection. This result was confirmed when the set of V-tip radii investigated was increased in the simulations. The trends in the results for the GFRP V-structures were similar to the equivalent steel plates. The delamination and total crack length were observed to increase with an increase in V-angle and charge mass. In general, the study found that GFRP V-structures were inferior to their equivalent mass steel V-structures in terms of panel rupture threshold. The GFRP V-structures exhibited lower transient deformation, but panel rupture on the rear face was observed at a lower charge mass. No tearing or rupture was observed in the steel V-structures tested at similar charge masses.
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    Open Access
    Response of composite and steel V-structures to localised air blast loading - Numerical and Experimental
    (2023) Shekhar, Vinay; Von Klemperer, Christopher; Langdon Genevieve
    This research investigated the blast performance of Glass-Fibre Reinforced Polymer (GFRP) Vstructures compared to equivalent mass steel V-structures. The blast performance was measured in terms of three metrics, namely, impulse transferred, maximum mid-point deflection and permanent damage/deformation. A series of blast experiments were performed on manufactured GFRP and steel V-structures. The GFRP V-structures were made using Vacuum Infusion (VI), using a 400 g m−2 woven E-glass and a Prime 20LV resin with a Low Viscosity (LV) slow hardener. The steel V-structures were manufactured by laser cutting the flat panel profiles from a sheet of 2 mm thick DOMEX-700 MC sheet and then Computer Numerical Control (CNC) bending them to the desired profile. Three panel configurations were experimentally blast tested, namely, a 105° V-angle with a 32 mm V-tip radius, a 105° V-angle with a 62 mm V-tip radius and a 120° V-angle with a 32 mm V-tip radius. Blast tests were performed by detonating PE4 charges ranging from 10 g to 40 g at a Stand-Off Distance (SOD) of 34 mm. Digital Image Correlation (DIC) was used to track the transient deformation of the V-structures, while the final deformed profile of the V-structures was determined using a 3D scanner. A series of numerical simulations were also performed on the GFRP and steel V-structures. The simulations used quarter symmetry models to utilise the symmetry of the experimental setup. The material model parameters were obtained from a series of material tests carried out on GFRP and steel specimens. The simulations were validated against the experimental results for a number of test cases for impulse transfer, and transient and permanent deformation. The simulations were then extended to look at a range of V-tip radii, V-angles and charge masses, while the SOD was held constant. For the steel V-structures, the blast experiments found that increasing the V-tip radius and Vangle resulted in an increase in impulse transferred as well as transient and permanent mid-point deflection. This result was confirmed when the set of V-tip radii investigated was increased in the simulations. The trends in the results for the GFRP V-structures were similar to the equivalent steel plates. The delamination and total crack length were observed to increase with an increase in V-angle and charge mass. In general, the study found that GFRP V-structures were inferior to their equivalent mass steel V-structures in terms of panel rupture threshold. The GFRP V-structures exhibited lower transient deformation, but panel rupture on the rear face was observed at a lower charge mass. No tearing or rupture was observed in the steel V-structures tested at similar charge masses.
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    Open Access
    Response of composite and steel V-structures to localised air blast loading - Numerical and Experimental
    (2023) Shekhar, Vinay; Von Klemperer, Christopher; Langdon Genevieve
    This research investigated the blast performance of Glass-Fibre Reinforced Polymer (GFRP) Vstructures compared to equivalent mass steel V-structures. The blast performance was measured in terms of three metrics, namely, impulse transferred, maximum mid-point deflection and permanent damage/deformation. A series of blast experiments were performed on manufactured GFRP and steel V-structures. The GFRP V-structures were made using Vacuum Infusion (VI), using a 400 g m−2 woven E-glass and a Prime 20LV resin with a Low Viscosity (LV) slow hardener. The steel V-structures were manufactured by laser cutting the flat panel profiles from a sheet of 2 mm thick DOMEX-700 MC sheet and then Computer Numerical Control (CNC) bending them to the desired profile. Three panel configurations were experimentally blast tested, namely, a 105° V-angle with a 32 mm V-tip radius, a 105° V-angle with a 62 mm V-tip radius and a 120° V-angle with a 32 mm V-tip radius. Blast tests were performed by detonating PE4 charges ranging from 10 g to 40 g at a Stand-Off Distance (SOD) of 34 mm. Digital Image Correlation (DIC) was used to track the transient deformation of the V-structures, while the final deformed profile of the V-structures was determined using a 3D scanner. A series of numerical simulations were also performed on the GFRP and steel V-structures. The simulations used quarter symmetry models to utilise the symmetry of the experimental setup. The material model parameters were obtained from a series of material tests carried out on GFRP and steel specimens. The simulations were validated against the experimental results for a number of test cases for impulse transfer, and transient and permanent deformation. The simulations were then extended to look at a range of V-tip radii, V-angles and charge masses, while the SOD was held constant. For the steel V-structures, the blast experiments found that increasing the V-tip radius and Vangle resulted in an increase in impulse transferred as well as transient and permanent mid-point deflection. This result was confirmed when the set of V-tip radii investigated was increased in the simulations. The trends in the results for the GFRP V-structures were similar to the equivalent steel plates. The delamination and total crack length were observed to increase with an increase in V-angle and charge mass. In general, the study found that GFRP V-structures were inferior to their equivalent mass steel V-structures in terms of panel rupture threshold. The GFRP V-structures exhibited lower transient deformation, but panel rupture on the rear face was observed at a lower charge mass. No tearing or rupture was observed in the steel V-structures tested at similar charge masses.
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    Open Access
    Response of composite and steel V-structures to localised air blast loading - Numerical and Experimental
    (2023) Shekhar, Vinay; Von Klemperer, Christopher; Langdon Genevieve
    This research investigated the blast performance of Glass-Fibre Reinforced Polymer (GFRP) Vstructures compared to equivalent mass steel V-structures. The blast performance was measured in terms of three metrics, namely, impulse transferred, maximum mid-point deflection and permanent damage/deformation. A series of blast experiments were performed on manufactured GFRP and steel V-structures. The GFRP V-structures were made using Vacuum Infusion (VI), using a 400 g m−2 woven E-glass and a Prime 20LV resin with a Low Viscosity (LV) slow hardener. The steel V-structures were manufactured by laser cutting the flat panel profiles from a sheet of 2 mm thick DOMEX-700 MC sheet and then Computer Numerical Control (CNC) bending them to the desired profile. Three panel configurations were experimentally blast tested, namely, a 105° V-angle with a 32 mm V-tip radius, a 105° V-angle with a 62 mm V-tip radius and a 120° V-angle with a 32 mm V-tip radius. Blast tests were performed by detonating PE4 charges ranging from 10 g to 40 g at a Stand-Off Distance (SOD) of 34 mm. Digital Image Correlation (DIC) was used to track the transient deformation of the V-structures, while the final deformed profile of the V-structures was determined using a 3D scanner. A series of numerical simulations were also performed on the GFRP and steel V-structures. The simulations used quarter symmetry models to utilise the symmetry of the experimental setup. The material model parameters were obtained from a series of material tests carried out on GFRP and steel specimens. The simulations were validated against the experimental results for a number of test cases for impulse transfer, and transient and permanent deformation. The simulations were then extended to look at a range of V-tip radii, V-angles and charge masses, while the SOD was held constant. For the steel V-structures, the blast experiments found that increasing the V-tip radius and Vangle resulted in an increase in impulse transferred as well as transient and permanent mid-point deflection. This result was confirmed when the set of V-tip radii investigated was increased in the simulations. The trends in the results for the GFRP V-structures were similar to the equivalent steel plates. The delamination and total crack length were observed to increase with an increase in V-angle and charge mass. In general, the study found that GFRP V-structures were inferior to their equivalent mass steel V-structures in terms of panel rupture threshold. The GFRP V-structures exhibited lower transient deformation, but panel rupture on the rear face was observed at a lower charge mass. No tearing or rupture was observed in the steel V-structures tested at similar charge masses.
  • No Thumbnail Available
    Item
    Open Access
    Response of composite and steel V-structures to localised air blast loading - Numerical and Experimental
    (2023) Shekhar, Vinay; Von Klemperer, Christopher; Langdon Genevieve
    This research investigated the blast performance of Glass-Fibre Reinforced Polymer (GFRP) Vstructures compared to equivalent mass steel V-structures. The blast performance was measured in terms of three metrics, namely, impulse transferred, maximum mid-point deflection and permanent damage/deformation. A series of blast experiments were performed on manufactured GFRP and steel V-structures. The GFRP V-structures were made using Vacuum Infusion (VI), using a 400 g m−2 woven E-glass and a Prime 20LV resin with a Low Viscosity (LV) slow hardener. The steel V-structures were manufactured by laser cutting the flat panel profiles from a sheet of 2 mm thick DOMEX-700 MC sheet and then Computer Numerical Control (CNC) bending them to the desired profile. Three panel configurations were experimentally blast tested, namely, a 105° V-angle with a 32 mm V-tip radius, a 105° V-angle with a 62 mm V-tip radius and a 120° V-angle with a 32 mm V-tip radius. Blast tests were performed by detonating PE4 charges ranging from 10 g to 40 g at a Stand-Off Distance (SOD) of 34 mm. Digital Image Correlation (DIC) was used to track the transient deformation of the V-structures, while the final deformed profile of the V-structures was determined using a 3D scanner. A series of numerical simulations were also performed on the GFRP and steel V-structures. The simulations used quarter symmetry models to utilise the symmetry of the experimental setup. The material model parameters were obtained from a series of material tests carried out on GFRP and steel specimens. The simulations were validated against the experimental results for a number of test cases for impulse transfer, and transient and permanent deformation. The simulations were then extended to look at a range of V-tip radii, V-angles and charge masses, while the SOD was held constant. For the steel V-structures, the blast experiments found that increasing the V-tip radius and Vangle resulted in an increase in impulse transferred as well as transient and permanent mid-point deflection. This result was confirmed when the set of V-tip radii investigated was increased in the simulations. The trends in the results for the GFRP V-structures were similar to the equivalent steel plates. The delamination and total crack length were observed to increase with an increase in V-angle and charge mass. In general, the study found that GFRP V-structures were inferior to their equivalent mass steel V-structures in terms of panel rupture threshold. The GFRP V-structures exhibited lower transient deformation, but panel rupture on the rear face was observed at a lower charge mass. No tearing or rupture was observed in the steel V-structures tested at similar charge masses.