Abaqus manual has stated that usually geostatic step must converge in 1 increment. But would it be considered correct if geostatic step converges in more than 1 increment like 0.25, 0.5, 0.75 and 1 s? The displacements are very low and stresses are also correct at the end of analysis.
Taking advantages of symmetry of loading acting on a circular foundation and soil, I have reduced to my model to half cylindrical (semicylindrical) model. Thus foundation and soil are both semi cylindrical. However, I do not get a successful geostatic step which I was getting in my complete 3-d...
ok alright, thanks for the support everybody. The reason why I have kept the seed size at the centre such small is I am trying to mobilize the full frictional resistance between soil and foundation. previously I was using a seed size of 0.95 but I could not get the favorable results. I checked...
ok let me try that. But from my literature study, I understood that C3D8R would be better to use instead tetrahedral elements. And hence I have been using them.
You are right, the file size is too large to upload. I am uploading another file. This time it is a circular foundation. It shows the way in which partitioning and seed sizes have been given. With this, I am getting 125300 elements. Can you have look at the file and edit it to reduce the no of...
Quarter symmetry may give me doubtful results. I have a moment acting about Y axis besides a vertical displacement and horizontal displacement. Therefore I believe I should not use quarter symmetry. Is there a problem with uploading files? I have been trying to upload the .cae file from...
By symmetry are you saying that I must reduce the size of model to half? I can reduce the model to half the present size but after applying the X-symm boundary conditions on the exposed side of foundation and soil, the model does not seem to give right results. The sides are roller (U1=U2=0) and...
Remember that the mesh quality is also important. I do not want to have lot of elements with face angle less than 35 or greater than 135 or aspect ratio greater than 10.
Attached is the figure of a simple cuboid of soil which I want to mesh. I have been able to mesh this part successfully but by putting a question here my main aim is to reduce the number of elements without affecting the seed size at the centre. At the centre there are 3 circles which have a...
...which is the case for my model, but you can do it without this also. I have applied a body force in downward direction and accordingly added *INITIAL CONDITIONS in the KEYWORDS. The direction is extremely important. In my case, upwards in + Z and downwards is - Z. The geostatic step is used...
...i.e. E and v. For boundary conditions, use roller (U1=0) for the sides and fixed for the bottom. Apply a body force as told before. Also use *Initial Conditions, Type= Stress, Geostatic by editing keywords file. Once you get this, then you can add the Mohr Coulomb Plasticity model and check...
body force is specified in force per unit volume. So I applied a body force equal to the value of density of the soil. For example, if density is 2556 Kg/m3, then convert this to N/m3 which comes 19000 N/m3. So just write 19000 in component 2 direction. I am assuming here that the vertical...
In the assembly module, you can use the option of ROTATE or TRANSLATE. By doing this, you change the local coordinates direction. I used this option to make + Z axis to - Z axis. Important to remember here is in the PART module, these directions do not change and only in ASSEMBLY module, the...
...force in downward direction( downward is negative and upward is positive). I could not my step with gravity and so I applied body force. Also apply *initial conditions, type=stress, geostatic. I guess you know this. This is my suggestion. Probably it may work. Then you can apply extra...
I want to create no tension elements between soil and foundation. To do this, I have created a thin circular layer of 0.01 m and assigned it the linear elastic properties of soil (for no tension, plastic propertes like mohr-coulomb model cannot be used). I also toggled on "No Tension" option in...
In Abaqus, I have an octagonal foundation resting on soil. I am required to produce a Vertical-Horizontal (VH) loading failure envelope for this system. A VH failure envelope for a circular footing resting on soil has been attached. I am describing briefly how this is achieved by using finite...
I was successful in removing the wedges by taking the partition cells off the geometry without affecting the shape of the octagon. With a seed size of 0.35 and partitioning in the form of triangle, I got warning for only 0.96% of elements. This is pretty good compared to my previous attempts...
