Skip to main content

ravitejk4u's blog

Numerical singularity in Abaqus

Submitted by ravitejk4u on

 

Hi All,

many a times in abaqus, we get numerical singularity warnings. which are mainly due to rigid body motion in one or more directions. This will generally happen when there is contact closing and opening phenomenon is happening.  How can we resolve these numerical singularities? Please post if you have any additional information.

 Thanks and Regards

Ravitej

HOW TO FIND K-DOMINANT REGION

Submitted by ravitejk4u on

hii all..

i am working on fracture mechanics. i had modeled a 4 pt bend specimen having single notch crack(in ABAQUS). i am trying to find the range of K-dominant region at the crack tip.i had modelled radial mesh at the crack tip and using 20 noded reduced integration elements. To analyze the K-dominat region, primarily i had compared the theoritical stress plots and computational stress plots. stress plots means Sxx Syy Sxy values plotted againt the angle(angle measured from uncracked segment) at particular radius.

Display Group Option in ABAQUS

Submitted by ravitejk4u on

Hi everyone

can anyone tell me how to use "display group" option in ABAQUS.

i have to find the total reaction force of set of all nodes on a particular surface. i had tried many times using "display group" option. but couldnt succeded.

or is there any other option to get the data from those set of nodes on a surface.  we have this kind of option in ANSYS, but what will the corresponding feature in ABAQUS.

Please help me in this regard. 

 

cheers

Ravitej 

Beam Theory for larger cross section

Submitted by ravitejk4u on

hi,

i want the mid point deflection in case of "four point bend test" on a specimen of length 140mm, width of 40mm and thickness of 10mm.

Problem is that, beam theory is valid if the cross-sectional dimensions are less than axial dimensions. Here this condition is violated. i had modeled the specimen in Abaqus and the diffection at mid point is almost double that of the actual diffection calculated from beam theory. 

how can i find the theoritical difflection at mid point in this case?

MODELING OF FGM IN ABAQUS

Submitted by ravitejk4u on

hello every one,

      i am Ravitej, doing my Mtech at IIT kanpur, India. Now, i am working  on FGM( funtionally Graded Materails). Can i model the FGM as a layered specimen with the youngs modulus varying according to layers. is there any special elements in abaqus, so that we can assign property variation along the thickness. 

Problem that i had faced with the layerd model is

1) stress is not continous at the interface of layers, then how can we believe that the solution obtained is correct