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Tony Mcnally - One of the best experts on this subject based on the ideXlab platform.

  • shape stabilised phase change materials based on a High melt viscosity hdpe and paraffin waxes
    Applied Energy, 2016
    Co-Authors: Pam Basheer, Yun Bai, Wei Sha, Tony Mcnally
    Abstract:

    Shape stabilised phase change materials (SSPCMs) based on a High Density poly(ethylene)(hv-HDPE) with High (H-PW, Tm=56–58°C) and low (L-PW, Tm=18–23°C) melting point paraffin waxes were readily prepared using twin-screw extrusion. The thermo-physical properties of these materials were assessed using a combination of techniques and their suitability for latent heat thermal energy storage (LHTES) assessed. The melt processing temperature (160°C) of the HDPE used was well below the onset of thermal decomposition of H-PW (220°C), but above that for L-PW (130°C), although the decomposition process extended over a range of 120°C and the residence time of L-PW in the extruder was <30s. The SSPCMs prepared had latent heats up to 89J/g and the enthalpy values for H-PW in the respective blends decreased with increasing H-PW loading, as a consequence of co-crystallisation of H-PW and hv-HDPE. Static and dynamic mechanical analysis confirmed both waxes have a plasticisation effect on this HDPE. Irrespective of the mode of deformation (tension, flexural, compression) modulus and stress decreased with increased wax loading in the blend, but the H-PW blends were mechanically superior to those with L-PW.

  • Shape stabilised phase change materials based on a High melt viscosity HDPE and paraffin waxes
    Applied Energy, 2016
    Co-Authors: Pam Basheer, Yun Bai, Wei Sha, Tony Mcnally
    Abstract:

    Shape stabilised phase change materials (SSPCMs) based on a High Density poly(ethylene)(hv-HDPE) with High (H-PW, Tm=56–58°C) and low (L-PW, Tm=18–23°C) melting point paraffin waxes were readily prepared using twin-screw extrusion. The thermo-physical properties of these materials were assessed using a combination of techniques and their suitability for latent heat thermal energy storage (LHTES) assessed. The melt processing temperature (160°C) of the HDPE used was well below the onset of thermal decomposition of H-PW (220°C), but above that for L-PW (130°C), although the decomposition process extended over a range of 120°C and the residence time of L-PW in the extruder was

Pam Basheer - One of the best experts on this subject based on the ideXlab platform.

  • shape stabilised phase change materials based on a High melt viscosity hdpe and paraffin waxes
    Applied Energy, 2016
    Co-Authors: Pam Basheer, Yun Bai, Wei Sha, Tony Mcnally
    Abstract:

    Shape stabilised phase change materials (SSPCMs) based on a High Density poly(ethylene)(hv-HDPE) with High (H-PW, Tm=56–58°C) and low (L-PW, Tm=18–23°C) melting point paraffin waxes were readily prepared using twin-screw extrusion. The thermo-physical properties of these materials were assessed using a combination of techniques and their suitability for latent heat thermal energy storage (LHTES) assessed. The melt processing temperature (160°C) of the HDPE used was well below the onset of thermal decomposition of H-PW (220°C), but above that for L-PW (130°C), although the decomposition process extended over a range of 120°C and the residence time of L-PW in the extruder was <30s. The SSPCMs prepared had latent heats up to 89J/g and the enthalpy values for H-PW in the respective blends decreased with increasing H-PW loading, as a consequence of co-crystallisation of H-PW and hv-HDPE. Static and dynamic mechanical analysis confirmed both waxes have a plasticisation effect on this HDPE. Irrespective of the mode of deformation (tension, flexural, compression) modulus and stress decreased with increased wax loading in the blend, but the H-PW blends were mechanically superior to those with L-PW.

  • Shape stabilised phase change materials based on a High melt viscosity HDPE and paraffin waxes
    Applied Energy, 2016
    Co-Authors: Pam Basheer, Yun Bai, Wei Sha, Tony Mcnally
    Abstract:

    Shape stabilised phase change materials (SSPCMs) based on a High Density poly(ethylene)(hv-HDPE) with High (H-PW, Tm=56–58°C) and low (L-PW, Tm=18–23°C) melting point paraffin waxes were readily prepared using twin-screw extrusion. The thermo-physical properties of these materials were assessed using a combination of techniques and their suitability for latent heat thermal energy storage (LHTES) assessed. The melt processing temperature (160°C) of the HDPE used was well below the onset of thermal decomposition of H-PW (220°C), but above that for L-PW (130°C), although the decomposition process extended over a range of 120°C and the residence time of L-PW in the extruder was

Mohamed Benguediab - One of the best experts on this subject based on the ideXlab platform.

  • J integral solution for semi-elliptical surface crack in High Density Poly-Ethylene pipe under bending
    Materials and Design, 2011
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, L Aminallah, Abdelwaheb Amrouche, Mohamed Benguediab, Noureddine Benseddiq
    Abstract:

    The goal of this work is to analyse the severity of semi-elliptical crack defects and to study the degree of damage in the Poly-Ethylene pipe in bending during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of the pipe. The three finite element method based on the computation of the J integral was used to analyse the fracture behaviour of these structures. The effect of the position, shape and size of the crack on the J integral values was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that the strain rates have a strong influence on the J integral values especially for circumferential crack at Higher bending moment. However, the energy for circumferential crack is more important compared to axial crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack, a/c = 0.2) where the J integral values becomes independently of the crack depth, this conclusion is opposite to the above for the Poly-Ethylene pipe subjected to internal pressure. We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks at critical crack size (a/c = 0.2 and a/t = 0.6). It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.

  • Three finite element analysis of semi-elliptical crack in High Density Poly-Ethylene pipe subjected to internal pressure
    Materials and Design, 2010
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, Noureddine Benseddiq, Abdelwaheb Amrouche, Gérard Mesmacque, Mohamed Benguediab
    Abstract:

    The principal objective of this work is to analyze the severity of semi-elliptical crack defects and to study the degree of damage in the equipment under internal pressure during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of Poly-Ethylene pipe. The tree finite element method based on the computation of the J integral was used to analyze the fracture behaviour of these structures. The effect of the position shape and size of the crack on the J integral was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that, whatever the material (strain rate) for a semi-elliptical crack, the J integral value has not an important variation with respect to the crack size. However, the energy for axial crack is more important compared to circumferential crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack). We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks. It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.

Noureddine Benseddiq - One of the best experts on this subject based on the ideXlab platform.

  • J integral solution for semi-elliptical surface crack in High Density Poly-Ethylene pipe under bending
    Materials and Design, 2011
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, L Aminallah, Abdelwaheb Amrouche, Mohamed Benguediab, Noureddine Benseddiq
    Abstract:

    The goal of this work is to analyse the severity of semi-elliptical crack defects and to study the degree of damage in the Poly-Ethylene pipe in bending during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of the pipe. The three finite element method based on the computation of the J integral was used to analyse the fracture behaviour of these structures. The effect of the position, shape and size of the crack on the J integral values was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that the strain rates have a strong influence on the J integral values especially for circumferential crack at Higher bending moment. However, the energy for circumferential crack is more important compared to axial crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack, a/c = 0.2) where the J integral values becomes independently of the crack depth, this conclusion is opposite to the above for the Poly-Ethylene pipe subjected to internal pressure. We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks at critical crack size (a/c = 0.2 and a/t = 0.6). It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.

  • Three finite element analysis of semi-elliptical crack in High Density Poly-Ethylene pipe subjected to internal pressure
    Materials and Design, 2010
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, Noureddine Benseddiq, Abdelwaheb Amrouche, Gérard Mesmacque, Mohamed Benguediab
    Abstract:

    The principal objective of this work is to analyze the severity of semi-elliptical crack defects and to study the degree of damage in the equipment under internal pressure during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of Poly-Ethylene pipe. The tree finite element method based on the computation of the J integral was used to analyze the fracture behaviour of these structures. The effect of the position shape and size of the crack on the J integral was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that, whatever the material (strain rate) for a semi-elliptical crack, the J integral value has not an important variation with respect to the crack size. However, the energy for axial crack is more important compared to circumferential crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack). We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks. It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.

A Benhamena - One of the best experts on this subject based on the ideXlab platform.

  • J integral solution for semi-elliptical surface crack in High Density Poly-Ethylene pipe under bending
    Materials and Design, 2011
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, L Aminallah, Abdelwaheb Amrouche, Mohamed Benguediab, Noureddine Benseddiq
    Abstract:

    The goal of this work is to analyse the severity of semi-elliptical crack defects and to study the degree of damage in the Poly-Ethylene pipe in bending during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of the pipe. The three finite element method based on the computation of the J integral was used to analyse the fracture behaviour of these structures. The effect of the position, shape and size of the crack on the J integral values was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that the strain rates have a strong influence on the J integral values especially for circumferential crack at Higher bending moment. However, the energy for circumferential crack is more important compared to axial crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack, a/c = 0.2) where the J integral values becomes independently of the crack depth, this conclusion is opposite to the above for the Poly-Ethylene pipe subjected to internal pressure. We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks at critical crack size (a/c = 0.2 and a/t = 0.6). It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.

  • Three finite element analysis of semi-elliptical crack in High Density Poly-Ethylene pipe subjected to internal pressure
    Materials and Design, 2010
    Co-Authors: A Benhamena, B. Bachir Bouiadjra, Noureddine Benseddiq, Abdelwaheb Amrouche, Gérard Mesmacque, Mohamed Benguediab
    Abstract:

    The principal objective of this work is to analyze the severity of semi-elliptical crack defects and to study the degree of damage in the equipment under internal pressure during the crack propagation. The semi-elliptical cracks are considered in this work located in different position in the wall of Poly-Ethylene pipe. The tree finite element method based on the computation of the J integral was used to analyze the fracture behaviour of these structures. The effect of the position shape and size of the crack on the J integral was Highlighted. The effects of strain rate and the temperature on the J integral values were also examined. The obtained results show that, whatever the material (strain rate) for a semi-elliptical crack, the J integral value has not an important variation with respect to the crack size. However, the energy for axial crack is more important compared to circumferential crack. The effect of the depth of the crack becomes important when the ratio (a/t) reaches a critical value of 0.6 (a/t = 0.6), especially when the ratio a/c is weak (semi-elliptical crack). We recall finally, that the temperature effect on circumferential cracks behaviour is more important compared to the axial cracks. It is also shown that in the wall of pipe, the internal cracks are more dangerous than the external cracks.