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Irene Fernandez Villegas - One of the best experts on this subject based on the ideXlab platform.
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interlaminar fracture toughness of 5hs carbon peek laminates a comparison between dcb els and mandrel peel tests
Polymer Testing, 2018Co-Authors: Francisco Sacchetti, Wouter Johannes Bernardus Grouve, Laurent Warnet, Irene Fernandez VillegasAbstract:The present work focuses on the applicability of the mandrel peel test to quantify the interlaminar fracture toughness of 5 harness satin woven fabric Carbon/PEEK composites. For this purpose, the Mandrel Peel (MP) test was compared to the Double Cantilever Beam (DCB) and End-Loaded Split (ELS) test in terms of experimental procedure and results obtained. The interlaminar toughness of the 5 harness Carbon/PEEK was measured both parallel and perpendicular to the predominant fibre direction at the interface. While stable crack propagation was observed in the ELS test, unstable crack propagation (stick-slip) was observed during both the DCB and the mandrel peel tests. In the case of the mandrel peel test, however, the unstable propagation was immediately arrested by the mandrel, limiting the instability and providing numerous crack re-initiation values per unit of crack length. This effect is expected to increase the statistical relevance of a single test and thereby to increase the reliability of the measured values as compared to DCB tests. A fractographic analysis was performed to study the nature of the crack propagation for the different testing techniques. The mandrel peel test was found to be a potentially plausible alternative to the DCB test for woven fabric reinforced composites.
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Interlaminar fracture toughness of 5HS Carbon/PEEK laminates. A comparison between DCB, ELS and mandrel peel tests
Polymer Testing, 2018Co-Authors: Francisco Sacchetti, Wouter Johannes Bernardus Grouve, Laurent Warnet, Irene Fernandez VillegasAbstract:The present work focuses on the applicability of the mandrel peel test to quantify the interlaminar fracture toughness of 5 harness satin woven fabric Carbon/PEEK composites. For this purpose, the Mandrel Peel (MP) test was compared to the Double Cantilever Beam (DCB) and End-Loaded Split (ELS) test in terms of experimental procedure and results obtained. The interlaminar toughness of the 5 harness Carbon/PEEK was measured both parallel and perpendicular to the predominant fibre direction at the interface. While stable crack propagation was observed in the ELS test, unstable crack propagation (stick-slip) was observed during both the DCB and the mandrel peel tests. In the case of the mandrel peel test, however, the unstable propagation was immediately arrested by the mandrel, limiting the instability and providing numerous crack re-initiation values per unit of crack length. This effect is expected to increase the statistical relevance of a single test and thereby to increase the reliability of the measured values as compared to DCB tests. A fractographic analysis was performed to study the nature of the crack propagation for the different testing techniques. The mandrel peel test was found to be a potentially plausible alternative to the DCB test for woven fabric reinforced composites.
H. Yang - One of the best experts on this subject based on the ideXlab platform.
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influence of different Mandrels on cross sectional deformation of the double ridge rectangular tube in rotary draw bending process
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Chunmei Liu, Yuli Liu, H. YangAbstract:Cross-sectional deformation of the double-ridged rectangular tube inevitably occurs in the rotary draw bending process. It has serious effect on the characteristic of microwave transmission and restricts the quality and performance of tube. Different Mandrels play different roles in the bending process, so the rigid and polyvinyl chloride (PVC) Mandrels are applied in the E-typed and H-typed rotary draw bending of double-ridged rectangular tube to study their influence on the cross-sectional deformation. Based on the platform of ABAQUS/Explicit, the three-dimensional finite element models for E-typed and H-typed rotary draw bending of H96 brass double-ridged rectangular tube with rigid and PVC Mandrels have been established and validated by experiment. Results show that whether in the E-typed or H-typed bending, the PVC mandrel has better inhibitory effect on the cross-sectional long-side deformation δ L, short-side deformation δ W, and spacing deformation between the bottom of ridge grooves δ w of the tube. And the PVC mandrel can be more helpful to reduce the width deformation of ridge grooves of the tube in H-typed bending. The rigid mandrel can restrain the width expansion deformation of outer ridge groove of the tube more effectively in E-typed bending. However, whether using the rigid or PVC mandrel, the width shrinkage deformation of inner ridge groove of the tube in E-typed bending is less affected by the type of Mandrels. And the width of two ridge grooves on sidewalls of the tube in H-typed bending also has the obvious shrinkage deformation.
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deformation behaviors of double ridged rectangular h96 tube in rotary draw bending under different mandrel types
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: Honglie Zhang, H. YangAbstract:Cross-sectional deformation is the most important formability assessment factor in rotary draw bending (RDB) of double-ridged rectangular tube (DRRT). Mandrel type influences the cross-sectional deformation directly. Due to the special cross-sectional shape of DRRT, the selection of right mandrel type becomes the most challenging task. Thus, a disconnect-type rigid mandrel and two kinds of PVC elastic mandrel were proposed. The influence of three Mandrels proposed on the cross-sectional deformation of DRRT was investigated. The results show that (1) the type I mandrel can control the height deformation of flange preferably and the type III mandrel can control the deformation of distance between outer and inner ridge groove well. With respect to restraining the width deformation of DRRT, the two Mandrels have their own merits. The performance of type II mandrel in preventing height deformation of DRRT is too poor to be used as a mandrel. (2) Only the type III mandrel is feasible when the mandrel support range is larger. Increasing the mandrel support range can decrease the height deformation obviously, but it has little effect on the width deformation. (3) When the size of DRRT is smaller, the type III mandrel can be a better option. However, when the size of DRRT increases, the height deformation of flange will increase evidently and the type I mandrel should be a better choice at this time.
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comparison between the effects of pvc mandrel and mandrel cores die on the forming quality of bending rectangular h96 tube
International Journal of Mechanical Sciences, 2013Co-Authors: Heng Li, H. YangAbstract:Abstract A new type of mandrel, which is PVC material and supposed as elastic–plastic deformable part in the simulation, is proposed to use in rotary-draw bending process, due to it can fill the tube entirely. The effect of PVC mandrel on the forming quality of rectangular H96 tube, such as tube damage distribution, wall thickness variation, section deformation, springback, is researched by comparing with the traditional mandrel-cores die. It is found that, the maximum damage value obtained with PVC mandrel is smaller than that with mandrel-cores die. The PVC mandrel leads to a smaller tube thickness variation and a more uniform tube thickness distribution compared with the mandrel-cores, for the PVC mandrel brings about smaller stress in the bending process. The PVC mandrel is recommended to be used in the rotary-draw bending process due to its advantage in the prevention of height deformation, though, the constraint effect on the tube width provided by the PVC mandrel is a little weaker than that by mandrel-cores die. Especially, the PVC mandrel with 1.5 times plastic hardening performs excellent well on the reduction of sectional height deformation of symmetrical line. The springback angle obtained with mandrel-cores die is smaller due to the retracting mandrel process. The PVC mandrel should be taken away from the tube before the springback occurs, which can be realized by heating the mandrel to soft.
Yannis P. Korkolis - One of the best experts on this subject based on the ideXlab platform.
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mechanics and full field deformation study of the ring hoop tension test
International Journal of Solids and Structures, 2014Co-Authors: Chris P Dick, Yannis P. KorkolisAbstract:Abstract We investigate the mechanics of the Ring Hoop Tension Test (RHTT), as a means to assess the properties of anisotropic tubes in the hoop direction. This test involves placing a ring extracted from the tube over two close-fitting D-shaped Mandrels that are then parted using a universal testing machine. Since the curvature of the ring does not change during loading, the ring undergoes only stretching. We determine the effects of contact pressure, radial stress, and friction between the tube and Mandrels using FEA simulations. The effects of the pre-existing thickness eccentricity and of the specimen-making procedure on the recorded RHTT response are also assessed with a combination of experiments and analysis. We tested tubes from Al-6061-T4 with a diameter/thickness ratio of 20. We found that as the friction increases beyond 0.1–0.15, the state of uniaxial tension is deteriorated, indicating that care must be taken to minimize the tube-mandrel friction. We determined that although these tubes have a relatively large thickness eccentricity (±4% of the nominal thickness), this had no effect on the recorded results. We showed that the tubes should not be turned to remove that eccentricity, as the machining process induces damage that is noticeable in the results. We found that the contact pressure and the contact-induced radial stress cause limited deviations from uniaxial tension, comparable to the case of a tube under axial load and internal pressure which is often used for assessing the material properties in the hoop direction. Central in our analyses is the knowledge of the hoop strain field, which was assessed using 3D Digital Image Correlation. We propose a data reduction procedure for RHTT that accounts for all the above effects. Finally, with all effects accounted for, we establish the anisotropy of the extruded Al-6061-T4 tubes studied.
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mechanics and full field deformation study of the ring hoop tension test
International Journal of Solids and Structures, 2014Co-Authors: Chris P Dick, Yannis P. KorkolisAbstract:Abstract We investigate the mechanics of the Ring Hoop Tension Test (RHTT), as a means to assess the properties of anisotropic tubes in the hoop direction. This test involves placing a ring extracted from the tube over two close-fitting D-shaped Mandrels that are then parted using a universal testing machine. Since the curvature of the ring does not change during loading, the ring undergoes only stretching. We determine the effects of contact pressure, radial stress, and friction between the tube and Mandrels using FEA simulations. The effects of the pre-existing thickness eccentricity and of the specimen-making procedure on the recorded RHTT response are also assessed with a combination of experiments and analysis. We tested tubes from Al-6061-T4 with a diameter/thickness ratio of 20. We found that as the friction increases beyond 0.1–0.15, the state of uniaxial tension is deteriorated, indicating that care must be taken to minimize the tube-mandrel friction. We determined that although these tubes have a relatively large thickness eccentricity (±4% of the nominal thickness), this had no effect on the recorded results. We showed that the tubes should not be turned to remove that eccentricity, as the machining process induces damage that is noticeable in the results. We found that the contact pressure and the contact-induced radial stress cause limited deviations from uniaxial tension, comparable to the case of a tube under axial load and internal pressure which is often used for assessing the material properties in the hoop direction. Central in our analyses is the knowledge of the hoop strain field, which was assessed using 3D Digital Image Correlation. We propose a data reduction procedure for RHTT that accounts for all the above effects. Finally, with all effects accounted for, we establish the anisotropy of the extruded Al-6061-T4 tubes studied.
Francisco Sacchetti - One of the best experts on this subject based on the ideXlab platform.
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interlaminar fracture toughness of 5hs carbon peek laminates a comparison between dcb els and mandrel peel tests
Polymer Testing, 2018Co-Authors: Francisco Sacchetti, Wouter Johannes Bernardus Grouve, Laurent Warnet, Irene Fernandez VillegasAbstract:The present work focuses on the applicability of the mandrel peel test to quantify the interlaminar fracture toughness of 5 harness satin woven fabric Carbon/PEEK composites. For this purpose, the Mandrel Peel (MP) test was compared to the Double Cantilever Beam (DCB) and End-Loaded Split (ELS) test in terms of experimental procedure and results obtained. The interlaminar toughness of the 5 harness Carbon/PEEK was measured both parallel and perpendicular to the predominant fibre direction at the interface. While stable crack propagation was observed in the ELS test, unstable crack propagation (stick-slip) was observed during both the DCB and the mandrel peel tests. In the case of the mandrel peel test, however, the unstable propagation was immediately arrested by the mandrel, limiting the instability and providing numerous crack re-initiation values per unit of crack length. This effect is expected to increase the statistical relevance of a single test and thereby to increase the reliability of the measured values as compared to DCB tests. A fractographic analysis was performed to study the nature of the crack propagation for the different testing techniques. The mandrel peel test was found to be a potentially plausible alternative to the DCB test for woven fabric reinforced composites.
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Interlaminar fracture toughness of 5HS Carbon/PEEK laminates. A comparison between DCB, ELS and mandrel peel tests
Polymer Testing, 2018Co-Authors: Francisco Sacchetti, Wouter Johannes Bernardus Grouve, Laurent Warnet, Irene Fernandez VillegasAbstract:The present work focuses on the applicability of the mandrel peel test to quantify the interlaminar fracture toughness of 5 harness satin woven fabric Carbon/PEEK composites. For this purpose, the Mandrel Peel (MP) test was compared to the Double Cantilever Beam (DCB) and End-Loaded Split (ELS) test in terms of experimental procedure and results obtained. The interlaminar toughness of the 5 harness Carbon/PEEK was measured both parallel and perpendicular to the predominant fibre direction at the interface. While stable crack propagation was observed in the ELS test, unstable crack propagation (stick-slip) was observed during both the DCB and the mandrel peel tests. In the case of the mandrel peel test, however, the unstable propagation was immediately arrested by the mandrel, limiting the instability and providing numerous crack re-initiation values per unit of crack length. This effect is expected to increase the statistical relevance of a single test and thereby to increase the reliability of the measured values as compared to DCB tests. A fractographic analysis was performed to study the nature of the crack propagation for the different testing techniques. The mandrel peel test was found to be a potentially plausible alternative to the DCB test for woven fabric reinforced composites.
Chris P Dick - One of the best experts on this subject based on the ideXlab platform.
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mechanics and full field deformation study of the ring hoop tension test
International Journal of Solids and Structures, 2014Co-Authors: Chris P Dick, Yannis P. KorkolisAbstract:Abstract We investigate the mechanics of the Ring Hoop Tension Test (RHTT), as a means to assess the properties of anisotropic tubes in the hoop direction. This test involves placing a ring extracted from the tube over two close-fitting D-shaped Mandrels that are then parted using a universal testing machine. Since the curvature of the ring does not change during loading, the ring undergoes only stretching. We determine the effects of contact pressure, radial stress, and friction between the tube and Mandrels using FEA simulations. The effects of the pre-existing thickness eccentricity and of the specimen-making procedure on the recorded RHTT response are also assessed with a combination of experiments and analysis. We tested tubes from Al-6061-T4 with a diameter/thickness ratio of 20. We found that as the friction increases beyond 0.1–0.15, the state of uniaxial tension is deteriorated, indicating that care must be taken to minimize the tube-mandrel friction. We determined that although these tubes have a relatively large thickness eccentricity (±4% of the nominal thickness), this had no effect on the recorded results. We showed that the tubes should not be turned to remove that eccentricity, as the machining process induces damage that is noticeable in the results. We found that the contact pressure and the contact-induced radial stress cause limited deviations from uniaxial tension, comparable to the case of a tube under axial load and internal pressure which is often used for assessing the material properties in the hoop direction. Central in our analyses is the knowledge of the hoop strain field, which was assessed using 3D Digital Image Correlation. We propose a data reduction procedure for RHTT that accounts for all the above effects. Finally, with all effects accounted for, we establish the anisotropy of the extruded Al-6061-T4 tubes studied.
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mechanics and full field deformation study of the ring hoop tension test
International Journal of Solids and Structures, 2014Co-Authors: Chris P Dick, Yannis P. KorkolisAbstract:Abstract We investigate the mechanics of the Ring Hoop Tension Test (RHTT), as a means to assess the properties of anisotropic tubes in the hoop direction. This test involves placing a ring extracted from the tube over two close-fitting D-shaped Mandrels that are then parted using a universal testing machine. Since the curvature of the ring does not change during loading, the ring undergoes only stretching. We determine the effects of contact pressure, radial stress, and friction between the tube and Mandrels using FEA simulations. The effects of the pre-existing thickness eccentricity and of the specimen-making procedure on the recorded RHTT response are also assessed with a combination of experiments and analysis. We tested tubes from Al-6061-T4 with a diameter/thickness ratio of 20. We found that as the friction increases beyond 0.1–0.15, the state of uniaxial tension is deteriorated, indicating that care must be taken to minimize the tube-mandrel friction. We determined that although these tubes have a relatively large thickness eccentricity (±4% of the nominal thickness), this had no effect on the recorded results. We showed that the tubes should not be turned to remove that eccentricity, as the machining process induces damage that is noticeable in the results. We found that the contact pressure and the contact-induced radial stress cause limited deviations from uniaxial tension, comparable to the case of a tube under axial load and internal pressure which is often used for assessing the material properties in the hoop direction. Central in our analyses is the knowledge of the hoop strain field, which was assessed using 3D Digital Image Correlation. We propose a data reduction procedure for RHTT that accounts for all the above effects. Finally, with all effects accounted for, we establish the anisotropy of the extruded Al-6061-T4 tubes studied.