Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response
The research presented in this paper focusses on the underwater blast resilience of a hybrid composite sandwich panel, consisting of both glass-fibre and carbon-fibre. The hybrid fibres were selected to optimise strength and stiffness during blast loading by promoting fibre interactions. In the blas...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
KeAi Communications Co., Ltd.
2020-12-01
|
| Series: | International Journal of Lightweight Materials and Manufacture |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2588840420300408 |
| _version_ | 1811223754902077440 |
|---|---|
| author | Emily Rolfe Robert Quinn George Irven David Brick John P. Dear Hari Arora |
| author_facet | Emily Rolfe Robert Quinn George Irven David Brick John P. Dear Hari Arora |
| author_sort | Emily Rolfe |
| collection | DOAJ |
| description | The research presented in this paper focusses on the underwater blast resilience of a hybrid composite sandwich panel, consisting of both glass-fibre and carbon-fibre. The hybrid fibres were selected to optimise strength and stiffness during blast loading by promoting fibre interactions. In the blast experiment, the aim was to capture full-field panel deflection during large-scale underwater blast using high-speed 3D Digital Image Correlation (DIC). The composite sandwich panel was partially submerged and subjected to a 1 kg PE7 charge at 1 m stand-off. The charge was aligned with the centre of the panel at a depth of 275 mm and mimicked the effect of a near-field subsurface mine. The DIC deflection data shows that the horizontal cross-section of the panel deforms in a parabolic shape until excessive deflection causes core shear cracking. The panel then forms the commonly observed “bathtub” deformation shape. DIC data highlighted the expected differences in initial conditions compared to air-blast experiments, including the pre-strains caused by the mass of water (hydrostatic pressure). Furthermore, water depth was shown to significantly influence panel deflection, strain and hence damage sustained under these conditions. Panel deformations and damage after blast was progressively more severe in regions deeper underwater, as pressures were higher and decayed slower compared to regions near the free surface.An identical hybrid composite sandwich panel was subjected to air blast; one panel underwent two 8 kg PE7 charges in succession at 8 m stand-off. DIC was also implemented to record the panel deformations during air blast. The air and underwater blast tests represent two different regimes of blast loading: one far-field in air and one near-field underwater. The difference in deflection development, caused by the differing fluid mediums and stand-off distances, is apparent from the full-field results. During underwater blast the panel underwent peak pressure loading of approximately 52.6 MPa whilst during air blast the panel was subjected to 67.7 kPa followed by 68.9 kPa peak pressure loads in succession. The two experiments demonstrate the response of the same hybrid composite sandwich panel under two differing blast regimes.The post-blast damage and strength of the hybrid panels following air and underwater blasts were evaluated. Post-blast testing revealed that the underwater blast causes significantly more damage compared to air blast, particularly debonding between the skins and core. The air blast panel sustains no visible rear skin/core debonding, whereas 13 regions of rear-face debonds are identified on the underwater blast panel. Sustaining no front-skin breakage was advantageous for retaining a high proportion of the compressive modulus for this hybrid layup following underwater blast. Damage mechanisms were interrelated. Determining the most detrimental type is not straightforward in real explosive and non-idealised experiments, however debonding was understandably shown to be significant. A further study to isolate failure modes and improve in situ instrumentation is ongoing. |
| first_indexed | 2024-04-12T08:37:49Z |
| format | Article |
| id | doaj.art-b719a449622c4561b55f97a87c698c70 |
| institution | Directory Open Access Journal |
| issn | 2588-8404 |
| language | English |
| last_indexed | 2024-04-12T08:37:49Z |
| publishDate | 2020-12-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | International Journal of Lightweight Materials and Manufacture |
| spelling | doaj.art-b719a449622c4561b55f97a87c698c702022-12-22T03:39:58ZengKeAi Communications Co., Ltd.International Journal of Lightweight Materials and Manufacture2588-84042020-12-0134387402Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading responseEmily Rolfe0Robert Quinn1George Irven2David Brick3John P. Dear4Hari Arora5Department of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UKDepartment of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UKDepartment of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UK; FAC Technology, 53 Lydden Grove, Wandsworth, London, SW18 4LW, UKRadnor Range Ltd, 11 Broadaxe Business Park, Presteigne, LD8 2UH, UKDepartment of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UKZienkiewicz Centre for Computational Engineering, College of Engineering, Swansea University, Swansea, SA1 8EN, UK; Corresponding author.The research presented in this paper focusses on the underwater blast resilience of a hybrid composite sandwich panel, consisting of both glass-fibre and carbon-fibre. The hybrid fibres were selected to optimise strength and stiffness during blast loading by promoting fibre interactions. In the blast experiment, the aim was to capture full-field panel deflection during large-scale underwater blast using high-speed 3D Digital Image Correlation (DIC). The composite sandwich panel was partially submerged and subjected to a 1 kg PE7 charge at 1 m stand-off. The charge was aligned with the centre of the panel at a depth of 275 mm and mimicked the effect of a near-field subsurface mine. The DIC deflection data shows that the horizontal cross-section of the panel deforms in a parabolic shape until excessive deflection causes core shear cracking. The panel then forms the commonly observed “bathtub” deformation shape. DIC data highlighted the expected differences in initial conditions compared to air-blast experiments, including the pre-strains caused by the mass of water (hydrostatic pressure). Furthermore, water depth was shown to significantly influence panel deflection, strain and hence damage sustained under these conditions. Panel deformations and damage after blast was progressively more severe in regions deeper underwater, as pressures were higher and decayed slower compared to regions near the free surface.An identical hybrid composite sandwich panel was subjected to air blast; one panel underwent two 8 kg PE7 charges in succession at 8 m stand-off. DIC was also implemented to record the panel deformations during air blast. The air and underwater blast tests represent two different regimes of blast loading: one far-field in air and one near-field underwater. The difference in deflection development, caused by the differing fluid mediums and stand-off distances, is apparent from the full-field results. During underwater blast the panel underwent peak pressure loading of approximately 52.6 MPa whilst during air blast the panel was subjected to 67.7 kPa followed by 68.9 kPa peak pressure loads in succession. The two experiments demonstrate the response of the same hybrid composite sandwich panel under two differing blast regimes.The post-blast damage and strength of the hybrid panels following air and underwater blasts were evaluated. Post-blast testing revealed that the underwater blast causes significantly more damage compared to air blast, particularly debonding between the skins and core. The air blast panel sustains no visible rear skin/core debonding, whereas 13 regions of rear-face debonds are identified on the underwater blast panel. Sustaining no front-skin breakage was advantageous for retaining a high proportion of the compressive modulus for this hybrid layup following underwater blast. Damage mechanisms were interrelated. Determining the most detrimental type is not straightforward in real explosive and non-idealised experiments, however debonding was understandably shown to be significant. A further study to isolate failure modes and improve in situ instrumentation is ongoing.http://www.sciencedirect.com/science/article/pii/S2588840420300408Underwater blastAir blastComposite sandwich panelHybrid compositeDigital image correlation |
| spellingShingle | Emily Rolfe Robert Quinn George Irven David Brick John P. Dear Hari Arora Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response International Journal of Lightweight Materials and Manufacture Underwater blast Air blast Composite sandwich panel Hybrid composite Digital image correlation |
| title | Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| title_full | Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| title_fullStr | Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| title_full_unstemmed | Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| title_short | Underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| title_sort | underwater blast loading of partially submerged sandwich composite materials in relation to air blast loading response |
| topic | Underwater blast Air blast Composite sandwich panel Hybrid composite Digital image correlation |
| url | http://www.sciencedirect.com/science/article/pii/S2588840420300408 |
| work_keys_str_mv | AT emilyrolfe underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse AT robertquinn underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse AT georgeirven underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse AT davidbrick underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse AT johnpdear underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse AT hariarora underwaterblastloadingofpartiallysubmergedsandwichcompositematerialsinrelationtoairblastloadingresponse |