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  1. saja11

    Indentation testing

    I have tried simple viscoelastic material peoperty for cartilage part but still getting same error. Job runs completely but get NaN values for stresses.
  2. saja11

    Indentation testing

    Hi, I am running a model (to imitate indentation test) in which I have two parts 1) Deformable part (Considered to be cartilage) and a rigid body. I have given material property to cartilage part using UMAT subroutine. I am giving displacement load of -0.1 to rigid part. I can run the job...
  3. saja11

    Controls explanation

    Element is C3D8P-(8-node trilinear displacement and pore pressure).
  4. saja11

    Controls explanation

    It's a knee joint cartilage model and implemented with fibril reinforced poroviscoelastic material (UMAT). As material is very soft, I was facing convergence issues. But typically changing constraint and displacement controls (lower values than default), model do converges. Maybe not all but it...
  5. saja11

    Controls explanation

    Hi, I am trying to converge my complex model by trying to play with controls parameters. However, it would be appreciated is someone can help me in understanding what these controls represents? I have tried to see manual but it would be nice if someone can help me in geeting these controls and...
  6. saja11

    Convergence problems with soft material properties

    Hi, I have a knee joint model which needs to be simulated with Fibril reinforced poro elastic material properties. The model run fine with stiffer material properties but when i run the model with soft material properties (resembling human cartilage tissue), I can these convergence errors. Can...
  7. saja11

    Max principal stresses

    Thank you for your response. Ok so I got that the single value is from centroid but are the 8 values of max stresses from 8 nodes of same element? Also it is not good approach to get max value from single element from centriod so I want to get average of centroid values from neighbouring four...
  8. saja11

    Max principal stresses

    Hei, I have two queries. I want to get max value of maximum principal stress at each time point. I want to know that what does this mean? Are these max principal stresses in each node of element and single value is their averages at centroid? Secondly, I want to get a max value of max...
  9. saja11

    Max values of parameters

    I am getting indexes of each max value from 23 cells using [maxVal idx] = max(stress_selected_{i}); But how can I access the above and below (eg. in total 3 values above and below that max value) in matlab?
  10. saja11

    Max values of parameters

    Sorry for my ignorance as I am new in python scripting but can you suggest how can I obtain coordinates of nodes with maximum values. In reference guide I have found function to get array of nodes that lie within the specified bounding box (getByBoundingBox) but I am not sure how to obtain...
  11. saja11

    Max values of parameters

    Hey, I am working on max and mean values of max principal stress and other parameters of a 3D shape in Abaqus. For taking max values, I am taking peak values (over contact area) from all nodes through each time point. But I want to take max values of parameters better option would be by taking...
  12. saja11

    Difference in graphs of confidence intervals and parametric test in SPM analysis

    Hi, I am simulating minimum principal strain of knee models. I am getting different graphs for Confidence intervals (showing statistical difference between MRI and X-ray based models) and parametric test graphs(no significant difference). Can someone explain me how to interpret these graphs.
  13. saja11

    Effect of void ratio on stress relaxation response

    Thanks for your reply. It is 3-D cylindrical model of cartilage. For boundary conditions: Lateral expansion is allowed Fix rotation of geometry Free fluid flow from the tissue allowed (por=0 on outer most surfaces). 5% Compression of tissue’s thickness I have attached...
  14. saja11

    Effect of void ratio on stress relaxation response

    I have to analyze the stress relaxation response (reaction force as a function of time) of a poroelastic,isotropic material (cartilage) that is compressed to 5% of its thickness in unconfined compression. Young modulus is 0.5 Mpa, poisson's ratio as 0.15 and permeability as 1e-8. Nlgeom is off...
  15. saja11

    Determining data from MRI DICOM

    Hi, I need to determine whether it's left knee's or right knee's lateral view and Anterior Posterior view in MRI DICOM data? I have used 3d-Slicer to get DICOM info but is there any way I can determine information about specific views in MRI DICOM?
  16. saja11

    Knee X-ray Image Analysis

    I have to measure maximum anterior-posterior length of bones (condyles) in X-ray images of knee. I am using ImageJ (Fiji) software for that. However, one problem is that I have to incorporate the phantom of 30mm in the readings as well. How I can do scaling for that in ImageJ?
  17. saja11

    Softwares recommendation for constructing 3-D joint models of knee from Planar X-rays

    Thanks for your reply..I have worked with CT-Scans in MIMICS/3-D Slicer but I am unsure that segmentation from x-rays is possible in them?Do I need any software which can buid statistical shape models from x-rays?
  18. saja11

    Need recommendations for constructing 3-D joint models of knee from Planar X-rays

    Thank you for your reply...Can't we build 3-D models from x-rays (even bi-planar) in MIMICS? In case of single planar x-ray can we use statistical shape models? https://mede-innovation.ac.uk/news-article/partner-news-combine-3d-models-x-ray-images-latest-release-mimics/
  19. saja11

    fast finite element model generation and simulation methods for knee joint

    Need to implement fast finite element model generation and simulation methods for knee joint from planar x-rays...need recommendation?
  20. saja11

    Need recommendations for constructing 3-D joint models of knee from Planar X-rays

    Need recommendations for constructing 3-D joint models of knee from Planar X-rays..what softwares are best for detailed modelling of knee joints (including ligaments, tendons, cartilage and meniscus) from planar x-rays??? Don't want to use image segmentation methods in MATLAB..not perfect in...

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