Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames

Zhiqiang Wang; Jingfu Peng; Guoliang Pang

doi:doi:10.11648/j.ae.20261002.11

Research Article |

| Peer-Reviewed

Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames

Zhiqiang Wang

, Jingfu Peng

, Guoliang Pang^*

Published in Applied Engineering (Volume 10, Issue 2)

Received: 10 August 2026 Accepted: 20 August 2026 Published: 9 September 2026

Views: Downloads:

Download PDF

Share This Article

Twitter
Linked In
Facebook

Abstract

As global demand for seafood escalates, offshore marine aquaculture has increasingly expanded into open-ocean environments. Gravity-type deep-water net cages are widely used in marine aquaculture due to their cost-effectiveness and resistance to wave action. The floating collar system, typically constructed from high-density polyethylene (HDPE) pipes, serves as the primary load-bearing component and plays a crucial role in maintaining overall structural safety and buoyancy, with the connecting frames arrangement being particularly crucial. However, there is no standardized spacing for connecting frames, making research on their mechanical influence essential for design optimization. This study systematically evaluated the static performance of net cages under varying frame spacing and cage sizes using numerical simulation software ANSYS. Results show that under tensile loading, maximum stress increases at an accelerating rate with larger frame spacing. In contrast, under bending and torsion, stress initially rises before declining. Equivalent stiffness consistently declines with greater spacing, though the rate varies by loading condition. Furthermore, enlarging the cage circumference consistently decreases equivalent stiffness across all cases and generally elevates maximum stress, particularly under tensile and bending loads. Notably, cage circumference exerts a more pronounced impact on mechanical performance than frame spacing, particularly in bending scenarios where structural deformation is most critical. Compared to torsion, bending loads result in higher maximum stress and lower equivalent stiffness, indicating that the structure is highly vulnerable to bending-induced deformation and requires additional reinforcement. These findings can offer practical guidance for optimizing the connecting frame arrangement and improving the structural design of floating collar systems in gravity-type deep-water net cages.

Published in	Applied Engineering (Volume 10, Issue 2)
DOI	10.11648/j.ae.20261002.11
Page(s)	17-30
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Net Cage, Floating Collar System, Connecting Frame, Numerical Simulation, Equivalent Stiffness

References

[1]	Naylor, R. L., Hardy, R. W., Buschmann, A. H., et al. A 20-year retrospective review of global aquaculture. Nature. 2021, 591, 551–563. https://doi.org/10.1038/s41586-021-03308-6
[2]	FAO. The State of World Fisheries and Aquaculture 2020. Rome, Italy: FAO; 2020.
[3]	Yu, J., Liu, J. Policies in the development of offshore cage aquaculture in China: evolution, performance, and prospects. Reviews in Fisheries Science & Aquaculture. 2023, 31, 216–232. https://doi.org/10.1080/23308249.2022.2103644
[4]	Cheng, H., Li, L., Ong, M. C. Comparative study of five commonly used gravity type fish cages under pure current conditions. Ocean Engineering. 2022, 250, 110977. https://doi.org/10.1016/j.oceaneng.2022.110977
[5]	Liu, S., Li, G., Liu, H., et al. Current development status of aquaculture equipment in China. Journal of Fisheries of China. 2023, 47(11), 119615. https://doi.org/10.11964/jfc.20231014186
[6]	Wang, C., Ma, M., Chu, Y., et al. Developments in modelling techniques for reliability design of aquaculture cages: A review. Journal of Marine Science and Engineering. 2024, 12(1), 103. https://doi.org/10.3390/jmse12010103
[7]	Fredriksson, D. W., DeCew, J., Tsukrov, I. Development of structural modelling techniques for evaluating HDPE plastic net pens used in marine aquaculture. Ocean Engineering. 2007, 34(16), 2124–2137. https://doi.org/10.1016/j.oceaneng.2007.04.007
[8]	Dong, G., Zheng, Y., Gui, F., et al. Research on the float collar of a gravity fish cage. Engineering Applications of Computational Fluid Mechanics. 2009, 3, 430–444. https://doi.org/10.1080/19942060.2009.11015281
[9]	Zhao, Y., Bai, X., Dong, G., et al. Numerical analysis of the elastic response of a floating collar in waves. Ocean Engineering. 2015, 95, 175–182. https://doi.org/10.1016/j.oceaneng.2014.12.015
[10]	Zhao, Y., Wang, X., DeCew, J., et al. Comparative study of two approaches to model the offshore fish cages. China Ocean Engineering. 2015, 29, 459–472. https://doi.org/10.1007/s13344-015-0032-0
[11]	Zhao, Y., Bai, X., Dong, G., et al. Deformation and stress distribution of floating collar of net cage in steady current. Ships and Offshore Structures. 2019, 14, 371–383. https://doi.org/10.1080/17445302.2016.1210321
[12]	Lee, C. W., Lee, G. H., Choe, M. Y., et al. Dynamic simulation of the fish cage net and floating collar subjected to currents and waves. In Proceedings of the ISOPE International Ocean and Polar Engineering Conference, Vancouver, Canada, 2008; pp. ISOPE-I-08-325.
[13]	Liu, Z. C., Soares, C. G. Experimental and numerical studies on the effect of the reinforced tubes on the drag forces of a gravity cage system. Ocean Engineering. 2024, 311, 118780. https://doi.org/10.1016/j.oceaneng.2024.118780
[14]	Liu, Z. C., Soares, C. G. Numerical study on the effect of cage reinforcement on the behaviour of the circular gravity cage. In Advances in Maritime Technology and Engineering. Boca Raton, FL, USA: CRC Press; 2024, pp. 541–545.
[15]	Fu, S., Moan, T. G. Dynamic analyses of floating fish cage collars in waves. Aquacultural Engineering. 2012, 47, 7–15. https://doi.org/10.1016/j.aquaeng.2011.12.001
[16]	Syalsabila, F., Prastianto, R. W., Hadiwidodo, Y. S., et al. Structural analysis of floating net cage bracket in current and wave. IOP Conf. Ser. Earth Environ. Sci. 2022, 972, 012017. https://doi.org/10.1088/1755-1315/972/1/012017
[17]	Syarifudin, M. R., Prastianto, R. W., Hadiwidodo, Y. S., et al. Strength analysis of offshore aquaculture net structure under wave and current loads. IOP Conf. Ser. Earth Environ. Sci. 2022, 972, 012018. https://doi.org/10.1088/1755-1315/972/1/012018
[18]	Pang, G., Wan, C., Sui, L., et al. Dynamic response simulation for a novel single-point mooring gravity-type deep-water net cage under irregular wave and current. Applied Sciences. 2025, 15, 1570. https://doi.org/10.3390/app15031570
[19]	Park, S. B., Lee, J., Lee, C. W. Accuracy improvement of numerical simulation with the determination of drag coefficients of floating collars. Aquacultural Engineering. 2020, 90, 102105. https://doi.org/10.1016/j.aquaeng.2020.102105
[20]	Xu, T., Hou, H., Dong, G., et al. Structural analysis of float collar for metal fish cage in waves. Turkish Journal of Fisheries and Aquatic Sciences. 2017, 17, 257–268. https://doi.org/10.4194/1303-2712-v17_2_04
[21]	Xu, T., Dong, G., Zhao, Y., et al. Hydrodynamic characteristics of floating pipes in random waves. In Proceedings of the ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, Nantes, France, 2013; V005T06A009. https://doi.org/10.1115/OMAE2013-10164
[22]	Qin, H., Yu, S., Li, P. Dynamic response of floating collar and cage under waves and current. Ocean Engineering. 2020, 205, 107330. https://doi.org/10.1016/j.oceaneng.2020.107330
[23]	Huang, X., Guo, G., Tao, Q., et al. Numerical simulation of deformations and forces of a floating fish cage collar in waves. Aquacultural Engineering. 2016, 74, 111–119. https://doi.org/10.1016/j.aquaeng.2016.07.003
[24]	Huang, X., Guo, G., Tao, Q., et al. Dynamic deformation of the floating collar of a net cage under the combined effect of waves and current. Aquacultural Engineering. 2018, 83, 47–56. https://doi.org/10.1016/j.aquaeng.2018.08.002
[25]	Huang, X., Liu, H., Hu, Y., et al. Deformation simulation and structural improvement design for floating collar of deep-water aquaculture net cage. Transactions of the Chinese Society of Agricultural Engineering. 2018, 34(15), 44–49. https://doi.org/10.11975/j.issn.1002-6819.2018.15.006
[26]	Liu, H., Huang, X., Wang, S., et al. Evaluation of the structural strength and failure for floating collar of a single-point mooring fish cage based on finite element method. Aquacultural Engineering. 2019, 85, 32–48. https://doi.org/10.1016/j.aquaeng.2018.12.007
[27]	Liu, H., Huang, X., Pang, G., et al. Structural mechanical properties of circular fish cages determined by finite element analysis and material test. Ocean Engineering. 2022, 261, 112083. https://doi.org/10.1016/j.oceaneng.2022.112083
[28]	Bai, X., Zhao, Y., Dong, G., et al. Probabilistic analysis and fatigue life assessment of floating collar of fish cage due to random wave loads. Applied Ocean Research. 2018, 81, 93–105. https://doi.org/10.1016/j.apor.2018.09.018
[29]	Bai, X., Xu, T., Zhao, Y., et al. Fatigue assessment for the floating collar of a fish cage using the deterministic method in waves. Aquacultural Engineering. 2016, 74, 131–142. https://doi.org/10.1016/j.aquaeng.2016.08.001
[30]	Zhang, Y., Guo, H., Liu, S., et al. Fatigue vulnerability of sea cage to storm wave loads. Journal of Marine Science and Technology. 2023, 28, 153–164. https://doi.org/10.1007/s00773-022-00915-4

Cite This Article

Plain Text BibTeX RIS

APA Style

Wang, Z., Peng, J., Pang, G. (2026). Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Applied Engineering, 10(2), 17-30. https://doi.org/10.11648/j.ae.20261002.11

Copy | Download

ACS Style

Wang, Z.; Peng, J.; Pang, G. Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Appl. Eng. 2026, 10(2), 17-30. doi: 10.11648/j.ae.20261002.11

Copy | Download

AMA Style

Wang Z, Peng J, Pang G. Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Appl Eng. 2026;10(2):17-30. doi: 10.11648/j.ae.20261002.11

Copy | Download

@article{10.11648/j.ae.20261002.11,
  author = {Zhiqiang Wang and Jingfu Peng and Guoliang Pang},
  title = {Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames},
  journal = {Applied Engineering},
  volume = {10},
  number = {2},
  pages = {17-30},
  doi = {10.11648/j.ae.20261002.11},
  url = {https://doi.org/10.11648/j.ae.20261002.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ae.20261002.11},
  abstract = {As global demand for seafood escalates, offshore marine aquaculture has increasingly expanded into open-ocean environments. Gravity-type deep-water net cages are widely used in marine aquaculture due to their cost-effectiveness and resistance to wave action. The floating collar system, typically constructed from high-density polyethylene (HDPE) pipes, serves as the primary load-bearing component and plays a crucial role in maintaining overall structural safety and buoyancy, with the connecting frames arrangement being particularly crucial. However, there is no standardized spacing for connecting frames, making research on their mechanical influence essential for design optimization. This study systematically evaluated the static performance of net cages under varying frame spacing and cage sizes using numerical simulation software ANSYS. Results show that under tensile loading, maximum stress increases at an accelerating rate with larger frame spacing. In contrast, under bending and torsion, stress initially rises before declining. Equivalent stiffness consistently declines with greater spacing, though the rate varies by loading condition. Furthermore, enlarging the cage circumference consistently decreases equivalent stiffness across all cases and generally elevates maximum stress, particularly under tensile and bending loads. Notably, cage circumference exerts a more pronounced impact on mechanical performance than frame spacing, particularly in bending scenarios where structural deformation is most critical. Compared to torsion, bending loads result in higher maximum stress and lower equivalent stiffness, indicating that the structure is highly vulnerable to bending-induced deformation and requires additional reinforcement. These findings can offer practical guidance for optimizing the connecting frame arrangement and improving the structural design of floating collar systems in gravity-type deep-water net cages.},
 year = {2026}
}

Copy | Download

TY  - JOUR
T1  - Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames
AU  - Zhiqiang Wang
AU  - Jingfu Peng
AU  - Guoliang Pang
Y1  - 2026/09/09
PY  - 2026
N1  - https://doi.org/10.11648/j.ae.20261002.11
DO  - 10.11648/j.ae.20261002.11
T2  - Applied Engineering
JF  - Applied Engineering
JO  - Applied Engineering
SP  - 17
EP  - 30
PB  - Science Publishing Group
SN  - 2994-7456
UR  - https://doi.org/10.11648/j.ae.20261002.11
AB  - As global demand for seafood escalates, offshore marine aquaculture has increasingly expanded into open-ocean environments. Gravity-type deep-water net cages are widely used in marine aquaculture due to their cost-effectiveness and resistance to wave action. The floating collar system, typically constructed from high-density polyethylene (HDPE) pipes, serves as the primary load-bearing component and plays a crucial role in maintaining overall structural safety and buoyancy, with the connecting frames arrangement being particularly crucial. However, there is no standardized spacing for connecting frames, making research on their mechanical influence essential for design optimization. This study systematically evaluated the static performance of net cages under varying frame spacing and cage sizes using numerical simulation software ANSYS. Results show that under tensile loading, maximum stress increases at an accelerating rate with larger frame spacing. In contrast, under bending and torsion, stress initially rises before declining. Equivalent stiffness consistently declines with greater spacing, though the rate varies by loading condition. Furthermore, enlarging the cage circumference consistently decreases equivalent stiffness across all cases and generally elevates maximum stress, particularly under tensile and bending loads. Notably, cage circumference exerts a more pronounced impact on mechanical performance than frame spacing, particularly in bending scenarios where structural deformation is most critical. Compared to torsion, bending loads result in higher maximum stress and lower equivalent stiffness, indicating that the structure is highly vulnerable to bending-induced deformation and requires additional reinforcement. These findings can offer practical guidance for optimizing the connecting frame arrangement and improving the structural design of floating collar systems in gravity-type deep-water net cages.
VL  - 10
IS  - 2
ER  -

Copy | Download

Author Information

Zhiqiang Wang

South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China

Contact Email

http://orcid.org/0009-0002-0901-6319
Jingfu Peng

South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China

Contact Email

http://orcid.org/0009-0001-7900-050X
Guoliang Pang

South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China;Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya, China

Contact Email

http://orcid.org/0000-0002-5880-0380

Download PDF

Submit an Article

Sections

Plain Text BibTeX RIS

APA Style

Wang, Z., Peng, J., Pang, G. (2026). Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Applied Engineering, 10(2), 17-30. https://doi.org/10.11648/j.ae.20261002.11

Copy | Download

ACS Style

Wang, Z.; Peng, J.; Pang, G. Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Appl. Eng. 2026, 10(2), 17-30. doi: 10.11648/j.ae.20261002.11

Copy | Download

AMA Style

Wang Z, Peng J, Pang G. Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames. Appl Eng. 2026;10(2):17-30. doi: 10.11648/j.ae.20261002.11

Copy | Download

@article{10.11648/j.ae.20261002.11,
  author = {Zhiqiang Wang and Jingfu Peng and Guoliang Pang},
  title = {Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames},
  journal = {Applied Engineering},
  volume = {10},
  number = {2},
  pages = {17-30},
  doi = {10.11648/j.ae.20261002.11},
  url = {https://doi.org/10.11648/j.ae.20261002.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ae.20261002.11},
  abstract = {As global demand for seafood escalates, offshore marine aquaculture has increasingly expanded into open-ocean environments. Gravity-type deep-water net cages are widely used in marine aquaculture due to their cost-effectiveness and resistance to wave action. The floating collar system, typically constructed from high-density polyethylene (HDPE) pipes, serves as the primary load-bearing component and plays a crucial role in maintaining overall structural safety and buoyancy, with the connecting frames arrangement being particularly crucial. However, there is no standardized spacing for connecting frames, making research on their mechanical influence essential for design optimization. This study systematically evaluated the static performance of net cages under varying frame spacing and cage sizes using numerical simulation software ANSYS. Results show that under tensile loading, maximum stress increases at an accelerating rate with larger frame spacing. In contrast, under bending and torsion, stress initially rises before declining. Equivalent stiffness consistently declines with greater spacing, though the rate varies by loading condition. Furthermore, enlarging the cage circumference consistently decreases equivalent stiffness across all cases and generally elevates maximum stress, particularly under tensile and bending loads. Notably, cage circumference exerts a more pronounced impact on mechanical performance than frame spacing, particularly in bending scenarios where structural deformation is most critical. Compared to torsion, bending loads result in higher maximum stress and lower equivalent stiffness, indicating that the structure is highly vulnerable to bending-induced deformation and requires additional reinforcement. These findings can offer practical guidance for optimizing the connecting frame arrangement and improving the structural design of floating collar systems in gravity-type deep-water net cages.},
 year = {2026}
}

Copy | Download

TY  - JOUR
T1  - Research on Static Mechanical Properties of Gravity-Type Deep-Water Net Cage Floating Collar System Under Different Spacing Between Connecting Frames
AU  - Zhiqiang Wang
AU  - Jingfu Peng
AU  - Guoliang Pang
Y1  - 2026/09/09
PY  - 2026
N1  - https://doi.org/10.11648/j.ae.20261002.11
DO  - 10.11648/j.ae.20261002.11
T2  - Applied Engineering
JF  - Applied Engineering
JO  - Applied Engineering
SP  - 17
EP  - 30
PB  - Science Publishing Group
SN  - 2994-7456
UR  - https://doi.org/10.11648/j.ae.20261002.11
AB  - As global demand for seafood escalates, offshore marine aquaculture has increasingly expanded into open-ocean environments. Gravity-type deep-water net cages are widely used in marine aquaculture due to their cost-effectiveness and resistance to wave action. The floating collar system, typically constructed from high-density polyethylene (HDPE) pipes, serves as the primary load-bearing component and plays a crucial role in maintaining overall structural safety and buoyancy, with the connecting frames arrangement being particularly crucial. However, there is no standardized spacing for connecting frames, making research on their mechanical influence essential for design optimization. This study systematically evaluated the static performance of net cages under varying frame spacing and cage sizes using numerical simulation software ANSYS. Results show that under tensile loading, maximum stress increases at an accelerating rate with larger frame spacing. In contrast, under bending and torsion, stress initially rises before declining. Equivalent stiffness consistently declines with greater spacing, though the rate varies by loading condition. Furthermore, enlarging the cage circumference consistently decreases equivalent stiffness across all cases and generally elevates maximum stress, particularly under tensile and bending loads. Notably, cage circumference exerts a more pronounced impact on mechanical performance than frame spacing, particularly in bending scenarios where structural deformation is most critical. Compared to torsion, bending loads result in higher maximum stress and lower equivalent stiffness, indicating that the structure is highly vulnerable to bending-induced deformation and requires additional reinforcement. These findings can offer practical guidance for optimizing the connecting frame arrangement and improving the structural design of floating collar systems in gravity-type deep-water net cages.
VL  - 10
IS  - 2
ER  -

Copy | Download