scholarly journals Verification and validation of numerical models for the materials of the lumbar spine

2022 ◽  
Vol 35 ◽  
pp. 115-123
Author(s):  
Galina Eremina ◽  
Alexey Smolin
Keyword(s):  
Lumbar Spine ◽  
Numerical Models ◽  
Verification And Validation

scholarly journals Verification and Validation of Numerical Models of the Transport of Insulation Debris

2012 ◽  
Vol 4 (3) ◽  
pp. 255-270
Author(s):  
G. M. Cartland Glover ◽  
A. Kratzsch ◽  
E. Krepper ◽  
S. Renger ◽  
A. Seeliger ◽  
...  
Keyword(s):  
Numerical Models ◽  
Verification And Validation

scholarly journals Mini Special Issue on Tsunami Numerical Modeling Benchmarks – Challenges of Tsunami Modeling Hackathon –

2021 ◽  
Vol 16 (7) ◽  
pp. 977-977
Author(s):  
Shunichi Koshimura
Keyword(s):  
Risk Assessment ◽  
Numerical Modeling ◽  
Numerical Models ◽  
Model Verification ◽  
Verification And Validation ◽  
Benchmark Problems ◽  
Tsunami Modeling ◽  
Special Issue ◽  
Inundation Maps ◽  
Tsunami Risk

Numerical simulation and modeling became an essential technology in tsunami research and disaster management. Various numerical models were proposed and utilized for the development of tsunami risk assessment, inundation maps, and evacuation plans. The model verification and validation standards would be crucial to ensure sufficient reliability of tsunami risk assessment, inundation maps, as well as a consistency among various efforts. Common approach to ensure sufficient accuracy and reliability of numerical modeling is developing benchmark problems of hydraulic experiments and to use them for numerical model’s verification and validation. To satisfy this requirement, “Tsunami Modeling Hackathon” was held in September 2020 to organize new benchmark problems in numerical modeling of tsunamis and to improve their reliability and accuracy. Hackathon is an intensive-gathering event of computer programmers and others involved in software development to create outcomes by the end of the event. This event was organized by Prof. Tomoyuki Takahashi of Kansai University and his colleagues, who led the tsunami research subcommittee in Japan Society of Civil Engineers (JSCE). Tsunami modeling hackathon, in which about 23 teams and 162 researchers joined, included experiment and modeling teams in seven benchmark problems: urban tsunami inundation, landslide tsunami, tsunami loading on seawalls and coastal structures, sediment transport, drift of floating objects. The modeling groups performed the blind tests to cross-validate and interpret the results of their simulations in seven benchmark problems given by the experiment groups and discussed the improvement. This special issue reports the outcomes of the tsunami modeling hackathon, and includes six papers (five in this issue, one in the regular issue). We hope this issue will provide useful insights for tsunami modelers and contribute to establishing a standardized way to ensure that various tsunami numerical models would be validated through the benchmark problems.

scholarly journals Ocean Energy Systems Wave Energy Modelling Task: Modelling, Verification and Validation of Wave Energy Converters

2019 ◽  
Vol 7 (11) ◽  
pp. 379 ◽  
Author(s):  
Wendt ◽  
Nielsen ◽  
Yu ◽  
Bingham ◽  
Eskilsson ◽  
...  
Keyword(s):  
Wave Energy ◽  
Potential Flow ◽  
Numerical Models ◽  
Energy Systems ◽  
Verification And Validation ◽  
Ocean Energy ◽  
Fully Nonlinear ◽  
Wave Energy Converters ◽  
Modelling Task ◽  
Energy Converters

The International Energy Agency Technology Collaboration Programme for Ocean Energy Systems (OES) initiated the OES Wave Energy Conversion Modelling Task, which focused on the verification and validation of numerical models for simulating wave energy converters (WECs). The long-term goal is to assess the accuracy of and establish confidence in the use of numerical models used in design as well as power performance assessment of WECs. To establish this confidence, the authors used different existing computational modelling tools to simulate given tasks to identify uncertainties related to simulation methodologies: (i) linear potential flow methods; (ii) weakly nonlinear Froude–Krylov methods; and (iii) fully nonlinear methods (fully nonlinear potential flow and Navier–Stokes models). This article summarizes the code-to-code task and code-to-experiment task that have been performed so far in this project, with a focus on investigating the impact of different levels of nonlinearities in the numerical models. Two different WECs were studied and simulated. The first was a heaving semi-submerged sphere, where free-decay tests and both regular and irregular wave cases were investigated in a code-to-code comparison. The second case was a heaving float corresponding to a physical model tested in a wave tank. We considered radiation, diffraction, and regular wave cases and compared quantities, such as the WEC motion, power output and hydrodynamic loading.

scholarly journals Convergence analysis and validation of a discrete element model of the human lumbar spine

2022 ◽  
Vol 3 (1) ◽  
pp. 62-70
Author(s):  
Galina Eremina ◽  
◽  
Alexey Smolin ◽  
Irina Martyshina ◽  
◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Bone Tissue ◽  
Vertebral Body ◽  
Loading Rate ◽  
Numerical Models ◽  
Fold Increase ◽  
Intervertebral Discs ◽  
Effective Stiffness ◽  
Structural Element

Degenerative diseases of the spine can lead to or hasten the onset of additional spinal problems that significantly reduce human mobility. The spine consists of vertebral bodies and intervertebral discs. The most degraded are intervertebral discs. The vertebral body consists of a shell (cortical bone tissue) and an internal content (cancellous bone tissue). The intervertebral disc is a complex structural element of the spine, consisting of the nucleus pulposus, annulus fibrosus, and cartilaginous plates. To develop numerical models for the vertebral body and intervertebral disc, first, it is necessary to verify and validate the models for the constituent elements of the lumbar spine. This paper, for the first time, presents discrete elements-based numerical models for the constituent parts of the lumbar spine, and their verification and validation. The models are validated using uniaxial compression experiments available in the literature. The model predictions are in good qualitative and quantitative agreement with the data of those experiments. The loading rate sensitivity analysis revealed that fluid-saturated porous materials are highly sensitive to loading rate: a 1000-fold increase in rate leads to the increase in effective stiffness of 130 % for the intervertebral disc, and a 250-fold increase in rate leads to the increase in effective stiffness of 50 % for the vertebral body. The developed model components can be used to create an L4-L5 segment model, which, in the future, will allow investigating the mechanical behavior of the spine under different types of loading.

scholarly journals Automated finite element meshing of the lumbar spine: Verification and validation with 18 specimen-specific models

2016 ◽  
Vol 49 (13) ◽  
pp. 2669-2676 ◽  
Author(s):  
J.Q. Campbell ◽  
D.J. Coombs ◽  
M. Rao ◽  
P.J. Rullkoetter ◽  
A.J. Petrella
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Verification And Validation ◽  
Finite Element Meshing

Impairment Tutorial: Recurrent Radioculpathy: Recurrent Radioculpathy and Apportionment

2002 ◽  
Vol 7 (4) ◽  
pp. 8-10
Author(s):  
Christopher R. Brigham ◽  
Leon H. Ensalada
Keyword(s):  
Lumbar Spine ◽  
Range Of Motion ◽  
Disk Herniation ◽  
Fourth Edition ◽  
Recurrent Injury ◽  
Injury Model ◽  
Whole Person ◽  
Spinal Region

Abstract Recurrent radiculopathy is evaluated by a different approach in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, compared to that in the Fourth Edition. The AMA Guides, Fifth Edition, specifies several occasions on which the range-of-motion (ROM), not the Diagnosis-related estimates (DRE) method, is used to rate spinal impairments. For example, the AMA Guides, Fifth Edition, clarifies that ROM is used only for radiculopathy caused by a recurrent injury, including when there is new (recurrent) disk herniation or a recurrent injury in the same spinal region. In the AMA Guides, Fourth Edition, radiculopathy was rated using the Injury Model, which is termed the DRE method in the Fifth Edition. Also, in the Fourth Edition, for the lumbar spine all radiculopathies resulted in the same impairment (10% whole person permanent impairment), based on that edition's philosophy that radiculopathy is not quantifiable and, once present, is permanent. A rating of recurrent radiculopathy suggests the presence of a previous impairment rating and may require apportionment, which is the process of allocating causation among two or more factors that caused or significantly contributed to an injury and resulting impairment. A case example shows the divergent results following evaluation using the Injury Model (Fourth Edition) and the ROM Method (Fifth Edition) and concludes that revisions to the latter for rating permanent impairments of the spine often will lead to different results compared to using the Fourth Edition.

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