Questions related to Finite Element Analysis
I am analyzing RC beam under elevated temperature using heat transfer approach. The temperature is applied uniformly over the entire surface. I have also defined Amplitude and thermal interaction.
There is no variation in nodal temperature.
Is there any issue in modelling?
#FEM #ABAQUS #heattransfer
I'm researching the best software to do FEA for hose construction based on elastomers (rubber) and metal cords. In the past we used MSC but wondering if ANSYS have been updated their tools/software to produce better results for complex elastomer/metal part composition.
I am currently testing a basic design for my research topic with a hollow cylinder.
The displacement was set as 0 on one end as a fix support and -5 in Y direction on another end.
The reaction solution i had is different from in Ansys Mechanical and i believe that the result generated from APDL was wrong.
The last screenshot is the result from APDL using .cbd file from Workbench mechanical
The result is still incorrect comparing to the result from Workbench Mechanical.
What is my mistakes here or any suggestion ?
Anybody knows how to change the density of materiel during a deformation process in a specific strain range, for example (when strain raise from 0.1 to 0.2) using VUMAT ABAQUS subroutine?
I am modelling a beam reinforced with GFRP bars on ATENA 2D. The experimental and analytical load-deflection behaviours are in agreement with each other however, my FE model terminates 10 KN before the experimental load due to stress concentration near to loading plate. I tried to avoid it by increasing the plate's surface area but it didn't work. Please guide me on how to prevent stress concentration.
I am going to model oxide layer growth on metal and I have referred the following paper;
Z. Wang, J.-L. Grosseau-Poussard, B. Panicaud, and C. Labergère, “Finite Element Analysis of Stress Evolution During the High-Temperature Oxidation of Ni30cr+ Cr2O3 Systems,” Journal of Alloys and Compounds, vol. 904, p. 164094, May 2022, doi: 10.1016/j.jallcom.2022.164094.
The model consists of the 3D cube (20x20x20μm) and up to 18μm a metal layer existed. Then 18 to 20μm is an air layer that facilitates oxide layer growth. The system is starting with the initial 25oC and the temperature has increased up to 900oC within 30 minutes. Then the system is kept for 10 hours at 900oC and the temperature has decreased to 25oC. During only the isothermal step, the oxide layer has grown according to an exponential function.
This simulation was done on ABAQUS User Material (UMAT) subroutine. Further, the first author told me (in a couple of email conversations) that he used the air layer's Young's Modulus low value and set STRESS and STRAIN zero to prevent impact on the system behaviour within every increment. As the paper, the sole objective of the air layer is to provide space for the oxide layer growth.
My question is how to set STRESS and STRAIN zero in every increment through a UMAT?
Please, how to use ABAQUS ''SWELLING'' option with Law as ''Input''. I have inserted a range of values for ''Strain rate'' and corresponding Field variable 1 - see attached screenshot file as pdf.
But when I run the job in ABAQUS it ONLY read the first value of the table (first row - as highlighted in the attached file) and ABAQUS doesn't read any other value for 'Strain rate' and 'Field 1'?
Please, can I use ONLY the tabular data (multiple values of Strain rate and corresponding Field 1) without using the subroutine USDFLD?
Many thanks for your support and time.
I have the following questions regarding vibration-based damage detection of a cantilever beam:
1-What is the purpose of discretizing the cantilever beam by finite element technique?
2-Do the number of discretized elements and their length affect the modal analysis( healthy and damaged natural frequency, mode shapes)?
3- Why do the biggest changes in natural frequency happened when the damage occurred near the fixed end and became smaller if the damage occurred far away from its fixed end?
I am doing an impact analysis in Abaqus/Explicit (as shown in image 1) using Johnson-Holmquist (JH-2) material model for brittle materials. I am expecting to get the simulation as like image 2 where the particle rebounded after the impact. But instead, I am getting something like image 3 where the particle is penetrating the substrate. Any ideas why this is happening? The only material parameter change is the strain rate coefficient (C) in JH-2 model, For image 2 it is 1, for image 3 it is 0.007
I appreciate any suggestions you can provide.
Hope you’re doing great
Assume I have two material properties MATERIAL1 and MATERIAL2. I start my model with MATERIAL1 and calculate each element’s (von misses) stress and if any element’s stress exceeds N MPA I change its material to MATERIAL2 and continue till all the elements’ materials
are altered to MATERIAL2.
For this purpose:
Do you suggest Abaqus scripting by the following method:
1. Run the job
2. Write elements’ stresses to an .odb file
3. Check the elements’ stresses by reading the .odb file and change the desired elements’ material to MATERIAL2
4. Run the next job
5. Continue the above-mentioned loop by a script till all the elements’ materials change to MATERIAL2
Do you suggest running a job and implementing Abaqus subroutines (USFLD etc)?
1. Which method is applicable?
2. What are the cons and pros of each one?
Thanks for your precious points.
PS: Let’s say the real model has 1000 elements or more and 5 different material properties to describe a small gap bone healing process.
Hope you're doing great.
I'm trying to learn and implement Abaqus subroutines (particularly USFLD) and am struggling with the following Abaqus terms' meanings and applications:
1. field variables
2. material point (and material point quantities)
would please help me out here with the definitions and examples of the above-mentioned terms since I haven't found any useful website links online.
Hello everybody How can a three-dimensional FE analysis of a threaded screw (inserted into a material with an insertion torque) be substituted with an axisymmetric analysis of the same problem? Please kindly share good references' links if are available. Best regards, Yunus.
Suppose there is two concentric hollow cylinder and by some metal forming process the inner cylinder is plastically fitted with the outer cylinder in such a way that there is sufficient contact pressure is generated between the two cylinder interface and they are plastically shrink fitted.
Now this assembly place in a high temperature and high pressure environment and due to creep there is decrease in contact pressure.
Can anybody suggest me how to modelled this whole process in COMSOL so that we can find out the decrease in contact pressure with time.
I also have to modelled that if there is a very small hole (gap) at the interface of two cylinder then how the diameter of this hole is changes with time?
If someone using other FEA software or code then please suggest?
Thanks for your valuable suggestions.
Here I attached a model in which two rectangles are compressed to each other by giving some displacement to the bottom rectangle and keeping the upper one fixed. There is a sufficient contact pressure generated at the interface in step 1 of the study (stationary). In step 2 (time-dependent), I analyze the effect of creep on this contact pressure and find that the contact pressure decreases with time, and the results are promising. Now I have to model a small hole at the interface (which will be deformed in step1), and in step2, I want to analyze the change in shape ( relaxation in deformed shape) of this hole with time(creep).
In this part, I am facing many errors in the simulation in terms of taking the initial values for step 2 from the step1.
Failed to find consistent initial values.
Iteration for finding elasto-plastic strain variables did not converge.
I am highly thankful for your valuable suggestions.
What are some good options for defining the constitutive elastic-plastic relation in FEM analysis? Are there any resources for stress-strain curves/data or JC parameters.
So there is a simple beam element on which I was experimenting, trying to find answers to the questions: What is the difference between body load on a constrained assembly (bolted onto a baseplate) and direct nodal load on the constrains? Is there any of these setups that is close to Large Mass Method?
I got some very interesting findings that need explanation. I bolded out the questions that need an answer. Please find the simulation details in the attached images!
- Free-free setups have many orders of magnitude lower response to the same unit acceleration load than fixed-free setups. Is this explainable physically, or is it only a simulation gimmick because of mode participation factors (99.99...% factor for rigid-body mode)?
- Also, when nodal acceleration is applied, if rigid-body mode is included, the response is the same as when omitted. Why? (.f06 was checked and it really uses the selected modes) And also if rigid-body mode is omitted from the body acceleration load type, the response is the same (whereas, when rigid-body mode is included, I got unit response because rigid-body mode dominates). Why?
- Enforced acceleration on one end of the free-free beam resulted in a fixed-free modal response. So I'm guessing enforced motion works like a fixed constraint in the modal analysis, then in the Frequency Response it works like a load. Is this statement true?
- In the fixed-free setups, nodal and body load types resulted in similar responses at the eigenfrequencies, but showed differences elsewhere. Why? Also, nodal load goes to unit response at 0Hz while body load goes to 0 response at 0Hz. Why?
Sidenote: I also made a reference run with SOL108 Direct Freq. Response with the fixed-free nodal load setup without damping, and got of course similar result to SOL111 same setup.
Thank you if anyone can answer my questions! The 'Help' of NX was not very helpful :(
I am currently solving a static structural problem using ansys. I have given all the inputs but stress is not transmitting across the body. I have attached the files and I am bit new to ansys. Please guide me through the problem.
I wanted to add a stiffener to the rectangular plate by considering the maximum deflection node to the nearest minimum deflection node.
I can add the stiffener by considering the maximum deflection node (coordinates) to the minimum deflection node (coordinates), but it is not the nearest one.
Could anybody tell me how can I get the nearest minimum deflection nodes???
Odb Abaqus script for maximum and minimum deflection nodes but not nearest
stepframe = odb.steps['Step-1'].frames[-1]
displacement = stepframe.fieldOutputs['U']
maxp = max([(g.data,g.nodeLabel) for g in field.values ])
minp = min([(g.nodeLabel) for g in field.values])
nodel_label = maxp
coordinate = f.nodes[nodel_label].coordinates
coordinate_01 =f. nodes[nodel_label_01].coordinates
Maximum_deflection = maxp
p_1 = coordinate
t_1 = coordinate
I am modelling a L-shaped shear wall in ABAQUS for my project. I have applied a cyclic loading on top surface of my specimen. I have extracted the "base shear vs drift data" (and obtained a backbone envelope curve from the hysteresis). Apart from this load-deflection curve I wish to determine time and position when first cracking and crushing of concrete starts. And the same for the yielding of rebars. Can anyone help me with this ?
Some people here have suggested to plot ALLPD vs time (for whole model) and note down the time when curve becomes non-zero, that's when cracking of concrete has initiated. What's the logic behind that? And what about crushing of concrete and yielding of rebars?
Note: There are many rebars, so practically impossible to compare all rebar nodes time history to determine the first yielding point.
I have a question regarding FEA analysis in bones.
I scanned a bone with a microCT device, and the result is pretty neat. To translate the data into the polygonal mesh topologized for FEA in Abaqus or Inventor, I have to segment the CT-stack (correct me if I'm wrong, I've just started to scratch the surface of this topic). Is there a "easy" way to segment the cortical bone and the trabecular bone as separated elements? If I understood correctly, to obtain a more confident result in FEA, these two tissues should be present in the final mesh...
Thanks to everyone eager to help :)
In the case of simulation of an iterative process (Let's say we have 30 iterations) in which elements' material properties need to be changed after each iteration based on the results (eg. strain field) of the previous iteration, which method is preferred and why?
linking Abaqus & MATLAB or Abaqus scripting and UMAT subroutines.
I've been having some issues with abaqus lately. After the last windows 10 update my Abaqus for student isn't working correctly. The response time is very high, I'm not even able to draw something because I click on some tool and the program is delayed one minute or more. I tried to look for some tutorial to fix it, but I didn't find it. Someone can help me?
Most of the researchers concerned with analytical study or numerical study use ANSYS for the FE Modeling. The awareness about NASTRAN is low. What may be the reason and Why?
I am looking for an open-source finite element analysis library for Python programming language.
I want to develop my own finite element software in the specific study and also for my academic studies. Please share your opinions about the various free FEM library for python with your experience.
I simulated a pile embedded in sand soil. The pile was subjected to lateral and vertical forces. The model was aborted. I have printed the "Job Diagnostic" to present the causes of the aborted model. The problem occurred because of the nodes at the contact surfaces between the soil and pile. Some nodes were overclosure, and others separated, as presented in the figure below. How can I solve this problem?
I am studying the performance of 2 wing models (with the same size, constraints, loading and material properties but different material distribution) using Nastran. Wing A is lighter and 24% stiffer than wing B and that is demonstrated in the static analysis (under a distributed load on the top skin).
The two wings have about the same fundamental frequency (34.25Hz and 34Hz). Using the relationship f=sqrt(K/m), the difference between the two frequencies should be significant.
Also, the divergence analysis yields exactly the same displacement for the two wings.
Does any one know what could be causing such results? why the divergence displacement is not smaller for wing A (since it is stiffer) and its frequency is not much higher than wing B?
Thank you in advance for your input.
I am running a model of concrete SOLID65 with LINK (bar) elements.
I have attached below my material properties and failure criteria.
The model has not converged yet.
Any tips on how to make the model converge?
We're trying to perform a finite element analysis (FEA) simulation on the application of force to the skin of a human limb. In order to set up the simulation we are in need of damping coefficients for two of the layers - skin and fat. We've searched for but cannot find separate values for those two tissue types. Can anyone point us to references for these?
Numerical simulation in Ansys was done on a full model made of 3D printed ABS plastic sample.
Material model used for simulation was extracted from a tensile test that was run on a 3D printed 100% infill (full volume) specimen.
While comparing experimental results and simulation results it was found that Force- elongation (displacement) diagram printed form numerical simulation is having large deviation from the experimental results, while stress strain diagram is in agreement with experimental results.
I have tried using large deflection and have got very similar results.
The diagrams are attached below, orange lines are experimental results, and blue lines are simulation results.
Can anyone help with suggestions why there is such large difference between experimental and simulation results and only in force-displacement diagram while stress-strain diagram has good agreement between experimental and numerical results? Why simulation results only have linear trend while I did include Multilinear isotropic hardening model?
I have question regarding the use of Abaqus.
My goal is to make an extensive FEA of the pelvic region to investigate fracture patterns (big plans I know). To do this I would like to model the contact between the pelvis bone (E=17GPa), cartilage (E=10.25MPa) and the femur head (E=20GPa), this is where I struggle loads. In this model the hemipelvis will be fixed at the sacroiliac joint and the pubis. The loads will be applied via the Femur head.
So I decided to take a step back, to investigate the contact properties, therefor I've made a simplified the contact model (see attachment) by making a simplified box (named bot) with half a sphere (R=12), then a layer of cartilage (named kraakbeen) with outer R=12mm and inner R=10mm. and then the femur head is simplified as a sphere with R=10mm. The inner surface of the bone is tied with outer-surface of cartilage. The contact between the cartilage and the femur is supposed to be friction-less.
The FEA is done in 2 steps. The first step (step-contact) is displacement step, where the head of the femur is displaced 0.01mm to ensure contact. (displacement is placed with a BC)
The second step (step-load) is the step in which a load (same direction as the displacement) of 2500N is applied.
Preferably I would like to have the displacement-BC removed in the second step and only have a influence of the load that's applied on the femur. However my model does not solve that way.
If I continue the displacement BC into the second step, my model is able to fully solve, however the results are not correct. Since the stresses do not chance during the second step (in which 2500N) is applied. Meaning the application of the load doesnt seem to have any influence.
Can anyone help me how I correctly apply the load to the model and have proper boundary conditions of the pelvic-cartilage-femur?
i am using a python script for a parametric study. This script generates .odb files automatically. The problem is, that i can't open the files with ABAQUS cause the Output database created by python is too recent. Error message: "... .odb is from a more recent release of ABAQUS."
The Version of python used by my ABAQUS Version is 2.7.3.
I would be glad about any tips on how to solve this problem. Unfortunatley upgrading ABAQUS is not an Option at the moment
Thanks in advance
I have three modules (in free form .f90 format) which are being called from inside of a UMAT subroutine in ABAQUS, in the following manner:
Here the subroutines from module_A and module_B are being called
end subroutine UMAT
Now, what is the appropriate format for writing these modules with UMAT subroutine? How to merge different module files into a single *.for file (free format)?
I am performing finite element analysis of an hyperelastic structure in ABAQUS with the use of UMAT subroutine. The anlaysis is done in two steps:
1. In the step1, the structure is deformed by 11 mm.
2. In Step2, mesh-to-mesh solution mapping is performed. Later, the structure is further deformed by 5mm.
When performing the second step, the requirement is that the final strain energy of step 1 (ALLSE) should be considered as a start point instead of starting over from zero again. In other words, the initial strain energy should be considered from the input file.
I am just trying to vibrate a plate with a horn (see attached figure) in one direction with ultrasonic vibrations in Abaqus. I am new to Abaqus, how can I apply an external vibration/vibrational load to surface of a plate? Harmonic analysis needs a force but can I manipulate it as a vibration? I am open to any suggestions.
I am trying to solve 2D heat flow in the finite element Galerkin method with the discretization of 40 triangular elements. I want to solve the problem with internal heat generation node-by-node(ie linearly distributed within each element) . I want to know how to solve the heat source term with the shape functions inside the Integral. Is it through Gauss quadrature rule? if yes, please explain me how .
1.I want to know how to solve the heat source term with the shape functions inside the Integral. Is it through Gauss quadrature rule? if yes, please explain me how .
2. Since the heat source is not constant, do I need to calculate for all the elements ? Since the triangular element has 3 nodes, does it require 3 gauss points?
Thanks and Regards,
Sunag R A.
I simulate a pile embedded in multi-layer soil (Five Layers: 3 layers of clay, and 2 layers of sand ), subjected to earthquake (El-Centro earthquake) as solid elements by using Abaqus. Why the present curve gives a good agreement at the beginning only? How could I improve the model?
I am performing a parametric study into the effects of various parameters on the size/shape of indentation in a pipeline.
For each combination of parameters, I would like to have a simplified length, width and height of the resulting indentation. I am trying to use coordinates data (from before and after the indenter strikes the pipe) taken from a node set (contained within the red box on the image) to achieve this.
I have a rough idea of how I will go about this:
- To find dent height/depth I will find the node with the greatest y displacement
- To find length and width I will look for nodes that are furthest from the centre (in X or Z direction) that have deformed by Xmm (to be decided), then I will measure the distance between them
How can I use MATLAB to process the coordinates data to find a L, W & H of each indentation?
There are roughly 2000 nodes. What methods/processes can I use to find the desired information, I am completely new to MATLAB and to the processing of large amounts of ABAQUS data.
The FEM discretized (meshed) geometry/domain is considered stiffer than the actual geometry/domain due to the assumption of variation of the displacement within each element. This is analogous to the displacement being constrained to vary in a particular fashion within each of the elements. This results in the stiffness of the discretized domain being greater than the actual domain. As the element size decreases (or the number of elements increases), the constraint on the displacement loosens due to the smaller size of the element and hence, the smaller constraint zone. Thus, the stiffness of the meshed domain decreases and approaches that of the actual domain as the number of elements is increased.
Based on the above reasoning, the natural frequencies (on increasing the number of elements) must converge from above to the actual value (i.e. converge from higher values to the actual value).
- Can this be considered to be strictly true?
- Has any deviation from it been observed (i.e. convergence from below or lower values to the actual value) and if so how can that trend be physically explained/interpreted?
I'm having trouble finding an effective way to simulate a submodel in solid elements obtaining boundary conditions from a shell global model.
I've applied everything described in Abaqus user's guide and the tutorial that uses shell-to-solid submodeling on an elbow pipe.
In my case I'm applying it on a region of a sailing yacht mast, the geometry is considerably simple in terms of meshing so a good hexahedral elements mesh is obtained, having nodes present in the middle of the mast's thickness, which corresponds to the shell surface.
Despite that, I keep having an error when simulating that states "Error in job: NO VALID ELEMENT TYPES FOUND IN GLOBAL MODEL" and no further details about the error are explicited.
I've read that this type of submodeling does not allow to use 5dof's in shell elements' nodes for the global model but that is not my case.
There is very little information available regarding this technique so any help would come in great hand. Does anyone have an idea on how to solve this?
My question is that I'm wondering why my hoop stress in my composite pressure vessel is coming out to be non-constant throughout the ply layer. Wondering if it's in my composite layup or something else. Images below should show composite layup, encasture boundry conditions, and FEA Visualization of irregular hoop stress. Any help would be greatly appreciated.
Hello, I have a static general simualtion, for which I hace created a specific Field Output request asking for those results (image).
However, when I check the results I don't have the option to choose these (image2)
Does anyone know why this is happening?
Thanks in advance
Many experimental results revealed that there is no sign of cartilage in implants' osseointegration process. Regarding the tiny gap between implant threads and surrounding bone, would the mechano-biological environment exclude endochondral ossification from the peri-implant healing process?
I am currently trying to create a contour plot(ABAQUS) of relative micromotions between two surfaces in contact. I have already developed a method for calculation of relative motions. However, I haven't been able to assign my obtained values to the nodes of the geometries that I am evaluating.
Until now, I have read that some people use subroutines to track paired nodes between two surfaces in contact and then they assign the obtained values in a form of a contour plot. Alternatively, developing a MATLAB code and creating a sort of scatter plot with the relative micromotions has also been discussed on some research works.
Nevertheless, I am trying to find a more friendly alternative that doesn't involve a developed code or the use of subroutines.
Creating a field variable from field output is not an option because the first task is to pair closest nodes between surfaces in contact, which is not possible using the operators available here.
If I need to explain myself better, I can provide more details. I will really appreciate any help on this matter.
I am trying to model Slab on grade subjected to impact load in ABAQUS/Explicit. I want to connect each node of slab to ground using springs. I cannot use direct "Connect points to ground" option in springs in ABAQUS as it is valid only in ABAQUS/Standard.
What would be the best way to model springs beneath the slab and perform the dynamic analysis? (Winkler Method)
I am trying to determine the relative motion between two surfaces in contact. Although I know how to calculate the relative motion, I don't know how to extract the paired nodes (closest nodes) of surfaces in ABAQUS when my geometry of study is undeformed.
For relative motion I will be using the following formula:
If there are contact surfaces named A and B, where there are i-th number of nodes:
X - Relative motion: square root( ( (X Deformed Node1B - X Deformed Node 1A) - (X Undeformed Node1B - X Undeformed Node 1A) )^2 )
Y - Relative motion: square root( ( (Y Deformed Node1B - Y Deformed Node 1A) - (Y Undeformed Node1B - Y Undeformed Node 1A) )^2 )
Z - Relative motion: square root( ( (Z Deformed Node1B - Z Deformed Node 1A) - (Z Undeformed Node1B - Z Undeformed Node 1A) )^2 )
Total relative motion: square root ( (X - Relative motion)^2 + (Y- Relative motion)^2 + (Z - Relative motion)^2 )
Please let me know if I can make my question more understandable or if there's more information required to make it clearer.
Non-linear problem on Implicit Ls-Dyna.
Unable to achieve convergence. If someone has experience in the Implicit solver of Ls-Dyna, please let me know.
Thanks in advance
hello how to input materials parameter for the following
elastic - plastic material
I have the following parameters only
young modulus and poisson's ratio
I know how to input everything except lame constants
I have found an answer here, http://www.cfd-online.com/Forums/ansys-meshing/127554-mesh-quality.html
please, someone can me is it way to evaluate the quality in the workbench. if not please suggest any other method to do so in ansys16.
Dear all, I have a problem with defining ZeroLenght element.
I want to connect black nodes with 4-dof (soil nodes) with green ones (intermediate nodes) with ZeroLenght element by defining p-y, t-z and q-z materials, and then connect green nodes with yellows (pile nodes with 6-dof) by equalDOF command.
Any idea for doing this correctly? I got this error:
"WARNING ZeroLength::setDomain cannot handle 3dofs at nodes in 4 d problem"
I think the problem is the fourth DOF of soil nodes that contain pore pressure of soil.
Please find attached the image T.jpg.
The image of the FE model attached is a hollow body with some prismatic textures on the interior surfaces. Here I need to select all the nodes at the interior surfaces of the FE model. I have tried to use:
NSEL, S, LOC, X, X1, X2
but as the body is having a certain curvature on one side, all the required nodes are not getting selected. And as the number of nodes is many i.e. above 100000, graphical picking seems to be a cumbersome task.
We know that locking in the finite element method (FEM) is a numerical artifact due to the choice of the approximation functions. A couple of implications of locking in a static analysis can be mentioned as follows
- A FEM model of a beam subjected to a point load at its tip can severely underpredict the tip displacement if the FEM model is prone to shear locking.
- A FEM model of a beam acted upon by pure bending moment would develop spurious membrane strains if the FEM model is prone to membrane locking.
As far as modal analysis is concerned, what is the effect of the locking phenomenon on the determination of the natural frequencies and mode shapes of the system?
Hello everyone! I have a query regarding the Torsional constant and the Polar moment of inertia being used in Ansys workbench for a non circular cross-section .
In the Ansys help, i found that for the special case of a circular cross-sections, the torsionnal constant is equal to the polar moment of inertia and calculated by using this formula: Ixx=J=Iyy+Izz. Could any one clarify as to what formulation Ansys follows for the calculation of the Torsional constant and Polar moment of inertia of a non circular cross section.
I am working on seismic analysis of shear walls. So I am trying to calibrate CDP parameters for my further research by comparing load-Disp hysteresis (experimental and ABAQUS analysis) of U wall under cyclic loading.
For Experimental data I am referring this article:
I have attached an image showing best match (along with CDP parameters) which I could get for E=7000 MPa, which is very less than usually taken values like 25MPa. Is this normal when doing nonlinear cyclic analysis?
And how can I make my curve look similar to experimental one (there is huge difference in peak values and shape of cycles - experimental result shows narrow cycles whereas my ABAQUS analysis is resulting in wider cycles)
Say that I have 'p' number of variables and 'm' number of constraint equations between these variables. Therefore, I must have 'p - m' independent variables, and the remaining variables can be related to the independent ones through the constraint equations. Is there any rationale for selecting these 'p - m' independent variables from available 'p' variables?
I am simulating piled raft foundation subjected to seismic load (earthquake) in ABAQUS. I have modeled soil as solid elements and Mohr-Coulomb parameter. I want to know how can I apply geometric damping (silent boundary) to prevent the reflection of seismic waves?
When I plot elements of a FE model with node numbering and multi plots ON, I am also able to see the nodes which are of elements that are opposite/adjacent/not relevant to a particular element of interest. Is there any option in ANSYS APDL to make sure that only the nodes of a particular element is only seen and not that of another element that is adjacent or opposite to that particular element of interest?
N.B: In the attached image, I don't want to see the red-marked nodes.
So far world knows agile has emerged from IT/software solution projects. The methodology/ concept of agile is so highly effective that companies now want to explore its scope in managing mechanical product development.
1 biggest challenge i see before even embarking on the concept is, having an agile approach in CAD. A CAD engineer will take several days in general to modify or create a new model. Similarly, FEA/CFD will take days to iterate constraints to reach a solution. This cycle time is too big to go the agile way. How can we break down this work chain and check midway to make sure the progress is in right direction and effort will not need a redo?
Mechanical engineers are orthodox in working pattern so to say. There has been many improvisations and upgrades in CAD software but none in working style or thinking style.