Science topic

# Finite Element Analysis - Science topic

A computer based method of simulating or analyzing the behavior of structures or components.

Questions related to Finite Element Analysis

In 1D cases Hermite shape functions can be easily implemented. However, in 2D cases, if we want to use cubic Hermite triangle element (10 DOFs), then it is pointed out that the transformation between the physical triangle and the reference triangle is not affine-equivalent (or it is nonconforming). In this case, if calculating the gradient matrix directly then it will lead to wrong results.

The nonconforming nature of cubic Hermite triangle element is mentioned in Reddy's "An introduction to nonlinear finite element analysis" (see the attached figure), however, further discussion and examples of applying cubic Hermite triangle element are not presented in this book.

I am wondering if there are any available books/references that cover the details of the information related to this question.

I know FEA for simple concrete including the material testing and structural members testing. As of now, I have been searching for FEA of self compacting concrete with varying proportions and new Supplementary cementitious materials such as Non-ferrous metallurgy slags, bauxite residue.

Can you suggest some document or resource for this.

i am trying to simulate a tunnel under blast loading in abaqus , i am using coupled eulerian lagrangian, I find some difficulties,Any help (tutorial ,steps) would be highly appreciated.

I conducted pipe stress analysis using CAESAR II. And now I am trying to create similar analysis but in this case I use ANSYS APDL.

I find a problem while creating the boundary conditions, where in ANSYS APDL I can't model the Y+ supports because ANSYS APDL only has an option to restraint movement in both Y- and Y+ direction (the UY option, as can be seen in Figure 2).

Can anyone help me to model the Y+ support in ANSYS APDL?

I'd like to appreciate any responses.

I would like to develop 2D open cell foam models which can be further used in the FE modelling. Could anyone please suggest any modelling tool?

Thank you

Hello Everyone,

I am trying to define a non-linear spring element in Abaqus using the following values.

-8505.0193, -40

-6854, -30

-5514.401, -20

-4075.366, -10

0, 0

4075.366, 10

5514.401, 20

6854, 30

8505.0193, 40.

It is working fine with positive values. But when I define zero or negative values. it is showing an error as

"The independent variables must be arranged in ascending order. This error may have been caused by a possible empty line on the datacards in the property definition."

What do the stiffness matrix's eigenvalues tell about the finite element's quality? I have read similar answers on ResearchGate, but many refer to dynamic analysis.

Hi All,

I am trying to generate the 3D corneal surface from the Zernike Polynomials. I am using the following steps, can anyone please let me know whether they are accurate

Step 1: Converted the cartesian data (x, y, z) to polar data (rho, theta, z)

Step 2: Nomalised the rho values, so that they will be less than one

Step 3: Based on the order, calculated the Zernike polynomials (Zpoly), (for example: if the order is 6, the number of polynomials is 28 )

Step 4: Zfit = C1 * Z1 + C2 * Z2 + C3 * Z3 + ......... + C28 * Z28

Step 5: Using regression analysis, calculated the coefficient (C) values

Step 6: Calculated the error between the predicted value (Zfit) and the actual elevation value (Z)

Step 7: Finally, converted the polar data (rho, theta, Zfit) to Cartesian coordinates to get the approximated corneal surface

Thanks & Regards,

Nithin

For more details, see the link : https://zurl.co/roQB

The objective of the FMVSS222 standard is to enhance the safety of school bus occupants by reducing the number of deaths and the severity of injuries resulting from impacts with structures within the vehicle during crashes and sudden driving maneuvers. Finite Element Analysis (FEA) using Abaqus software allows to ensure compliance with the norms without conducting high-priced physical tests.

Specifically, the focus was on the passenger seat of the school bus, which has another seat in front of it. It was subjected to the application of force through loading bars.

I am modeling a concrete cylinder compression test (see attached). Loading is applied along z direction, and I am checking the sigma_33 stresses. I am having maximum signma_33 at the element centroid around 78 MPa (see attached graph). I don't get it why it is higher than the ultimate concrete strength of concrete (58 MPa).

Which stress does ABAQUS consider to check yielding and damage for concrete material?

Can you please recommend me any useful material that will help me to understand CDP model generally used in ABAQUS for concrete materials? I have read some fundamental papers like Lee and Fenves, Lubliner et. al., etc. to understand the theory behind it. I got it to some extent. Now, I am looking for something that describes CDP from practical point of view. My main goal is to understand the output that I am getting from my analysis.

Any sort of information will be greatly appreciated.

Hi all,

I am trying to model a contact problem in DIANA FEA. I went through the DIANA manual and found that DIANA has contact elements which imposes the contact constraint. But there aren't any tutorial or examples available online to do this.

The material property for the contact element has two options target and contactor. When I try to assign the contact element material properties to an existing steel object, the object loses its steel material properties and contains only the contact elements properties which is friction and penetration depth.

Could someone explain how can I assign the contact constraint in DIANA when two steel cubes are touching each other.

ABAQUS ERROR: ONE OF THE ELEMENT IS CLOSE TO PARALLEL WITH ITS BEAM SECTION AXIS, so I'd like to know how to solve this problem? The element property is beam element, so I should define the section oritention in all elements.

Below you can find equetion which express flow curve which describes the plastic deformation behavior of a material in a uniaxial tensile (or compression) test. I looking for books, articles which gives me information how values of C and n depends on geometry (eg. diamater and wallthicknes of drawn tube) as well as initial mechanical properties, before material work hardening. Do wires and rods of the same material but with different dimensions have a different form of the flow-curve, or does it depend only on the initial properties of the material?

Hello dear colleagues

Hope you're fine.

I'm trying to model a threaded connection with a 2D axisymmetric model.

I need to make several models with slight changes and differences.

In some models, once the job is submitted, before the analysis gets started, it gets aborted due to "some nodes have Negative coordinate values" error.

When I check the error node set, they are all placed on the axis of symmetry.

I tried several ideas to work this out but none of them was successful like:

>changing element type,

>constraining the part in the direction prependicular to the axis of symmetry

>Using another datumn coordinate system

I appreciate it if you have any ideas to fix this error.

PS: some other models get solved without this error while these models are copied from one another and I couldn't see any difference seem to be related to this error between them

I am using VDFLUX for surface heat flux and VUSDFLD for element deletion.

I am just writing the two subroutines and submitting it during job. It's not throwing any error but it's not applying the surface heat flux load.

How to do quasi static compression test (2mm/min) in ansys Workbench? Please help me

Hello everyone,

I am currently conducting a stencil printing simulation using ABAQUS. The simulation needs to be performed in 20 different locations on the stencil, requiring a separate simulation for each of these locations. In my case, all components remain fixed, and only the location of the blade changes across these 20 locations. The simulation consists of seven steps. Throughout these 20 simulations, all conditions remain identical from the first step until the fifth step. However, after the fifth step, I change the blade's location in the sixth step and continue the simulation in the seventh step.

Given that the first five steps are the same in all simulations, I would like to explore if there is a way to execute these steps only once and then reuse or restart the results for the remaining 19 simulations. In other words, I aim to find a method that avoids repeating the first five steps in the subsequent simulations. Although I have attempted to utilize the restart option, it did not prove successful due to the blade's location change in the sixth step.

Finite element method will be used to determine the stress-strain of a 3D composite material made structure.

I am a final year Masters's Student from Heriot-Watt University currently working on my dissertation project titled "A THEORETICAL ASSESSMENT OF THE STRUCTURE OF A LIQUID STORAGE TANK UNDER SEISMIC FORCES" with the following objectives:

1. Verification of Current Theories (Housner, Preethi, and Malhotra) of liquid Structure Behavior (sloshing wave height) under seismic forces for petroleum-filled storage tanks using Finite Element Modelling and Finite Element Analysis.

2. Assessment of the possible failure mechanism of the superstructure of the various liquid storage vessels under exposure to seismic forces using Finite Element Modelling and Finite Element Analysis based on the API 650 Design Standard.

3. Proposal and initial assessment of the effectiveness of a Bass Isolation System on the sloshing wave height using Finite Element Modelling and Finite Element Analysis.

Can the

**Ansys modal analysis module**be used to model a fluid-filled storage tank and determine the sloshing wave height along with the impulsive and convective mass components of the fluid based on the application of specific Acceleration, Velocity, and displacement values?Can I subsequently transfer the model to the

**Ansys Static Structural Module**to determine the various resulting stresses that will develop within the tank structure due to the seismic forces and the fluid-structure interactions?If not, can you guys offer any advice on what methodology I should take?

Dear Researchers :

I will very much appreciate the help.

I have a 2D model in COMSOL. It's a plate, made of Polyethylene. An AC Voltage is applied on the upper electrode, the lower electrode is on V=0 (ground)

The sinusoidal function of the voltage is : Vo*Sin[wt + phi] where phi = 0 and V_o is equal to 2.4 kV

I am attaching an image of my 2D Geometry

I am solving the model in two steps

Step 1 : Using a Time Dependent Study (just to solve the physics of the electric currents module)

Step 2 : A stationary solver, to solve the Heat Transfer in Solids part.

I used the Multiphysics interphase of Electromagnetic Heating

I can correctly solve the Electric part of the model

But for the temperature, this is the graph that I get, which of course is not correct

Does someone might know where the mistake might be ?

Best Regards all :)

Hello everyone,

I am currently investigating the phenomenon known as the Indentation Size Effect (ISE) using the Finite Element Method (FEM). My research involves conducting indentation tests through simulation using ABAQUS.

Here are some specifications of the model:

- It is a 2D axisymmetric model.
- The indenter is represented as a rigid body and possesses a semi-angle of 70.3°.
- The specimen material is assumed to be homogeneous and isotropic, characterized by an ideal elastoplastic model.
- Mesh is refined near the indenter tip to capture stress concentration accurately.
- Contact Interaction: Surface-to-surface contact, Tangential behaviour - Frictionless, Normal behaviour - Hard Contact.

I have conducted simulations at various depths, ranging from 500 nm to 5000 nm. To determine the hardness, I have employed the Oliver-Pharr Method. According to the concept of ISE, the hardness should decrease as the indentation depth or load increases. However, in my results, I have observed that the hardness remains almost constant regardless of the depth. Consequently, I am unable to observe the anticipated trend associated with the Indentation Size Effect in my findings.

For your convenience, I have attached the .cae file and the hardness vs indentation depth plot.

I would greatly appreciate any assistance or insights you can provide to help me address this issue.

Thank you all in advance.

Dear colleagues

I'm modeling bone healing around dental implants using Abaqus subroutines (UMAT / USDFLD).

I wonder:

1. How SDVs of

**current and previous increment**can be accessed in the current increment through**UMAT**?2. and how SDVs of

**previous increments**(eg. 10 previous increments) can be accessed in the current increment through**USDFLD**?Thanks in advance,

Yunus.

PS: The value of SDVs at the beginning of the current increment can be accessed by GETVRM utility routine in USDFLD

Could any one provide me with a MATLAB code for fixed-fixed beam that calculates the Mass and Stiffness matrices, Natural frequency, and mode shapes.

Hi,

I am modeling a reinforced concrete(RC) slab in DIANA FEA.

The RC slab is simply mounted on a steel girder (see config 1)
Therefore, there is no bonding between the RC slab and the steel girder.
In order to satisfy these interface conditions, it is set as shown in Figure 2.
When a vertical downward pressing force (bending stress) from the center of the slab is applied, it is expected that the slab located on the girder will be lifted up (as in the principle of lever). See Fig 3).
As expected, the upward displacement of the slab on the girder occurred, but in some sections it appeared as if it had been bonded and no lifting occurred (See Figure 4)
Please advise why this is happening and what interface setting should be done.

Thank you.

What references do you recommend? What theory should I use to model unsteady aerodynamics? Is it better to use software or coding? Please share some insights.

I'm struggling to obtain the right behavior of gfrp bars, in the process of validating my model i achieve a bilinear behavior in the displacement x force graph when using gfrp bars as reinforcement, but in the research that i'm using the experimental behavior was linear. Even though i've tried to change a lot of parameters in my model I still couldn't obtain something close.

The model has steel stirrups and upper layer reinforcement and only the lower reinforcement uses GFRP bars.

The bars were modeled as wire T3D2 and the beam as solid c3d8r

For the properties data:

For concrete i'm using de young's modulus, poisson and CDP

For GFRP bars young's modulus, poisson and tensile strenght also rupture strenght

Anyone knows what can i do to correct the behavior that i'm having?

In the image i show the behavior that i need in black and what i am obtaining in the other colors

Hello everyone,

I have a problem calculating the modal assurance criterion (MAC) of a experimental mode shape and a FEM mode shape. I can calculate the AutoMAC for each mode shape, for which the values are all correct. Both matrices show that the same mode shape gets a value of 1, while the rest is near 0.

However if I now apply the same formula to the normal MAC nothing seems right. The sensors for the experimental mode shape can measure displacement in one DOF. So at each node the displacement is a complex value in the direction of one of the local X, Y or Z-axis. The FEM mode shape contains real values at each node and the displacement can occur in all 3 DOFs.

I hope someone can help me resolve this problem.

Thanks in advance!

I have modeled a two-dimensional plane strain embankment in Abaqus. I did not apply any forces, boundary conditions, or displacement to the infinite element, and I defined it as CINPE4. I defined two steps for the model: the first step is static to apply gravity load, and the second step is dynamic implicit. In the second step, I applied the time history of the Loma Prieta earthquake horizontally on the base of the model. Ultimately, I observe a concentration of shear strain at the boundary between the infinite and finite elements, as shown in the image below.

In addition, I have attached my model's .inp file to this question for reference.

I have some STL files describing the geometry I intend to use in FEA simulation in CalculiX code. I'm struggling to find resources on how I can do this. Any advice would be very much appreciated !

Explicit scheme : By varying the mesh size, we see that for smaller sizes, the computation time for the usual mass matrix (not diagonal) exceeds that of the lumped mass matrix (diagonal). This I understand. But when the mesh size becomes large the computation time for the lumped mass matrix (diagonal) exceeds that of the usual mass matrix (not diagonal). Why ?

**I need to carry out a finite element analysis of the human foot. But I am not getting the CT scan file with more than 128 slices. Is it possible to model a human foot with 128 slices? How many slices at a minimum are needed for proper modeling and Finite Element Analysis?**

Hi :),

I currently am doing a project where I have to analyse the deformation of a circular plate on abaqus , as loads I have added a pressure load and a body force and as boundary condition I have fixed ( encastre). How can I define a deflection on abaqus or what expression can I use in order to input in the software?

thank you in advance

Hello,

I have several structures which is composed of an upper body and an under body. I want to compare different upper body with each other (therefore several different structures) with Finite element software. I also want to lower the stiffness of these under body to have the same stiffness on the different models and thus be able to compare upper body between them. For this the solution is to vary the Young's Modulus of these different under body. The problem is that some are longer than others in terms of length. How to take this parameter into account?

I'm looking to develop my knowledge to get hired as a stress engineer for my first job onwards. It seems like reinventing the wheel sometimes to try and understand how the software works. Is it bad / waste of time to do that?

I have made a model in Abaqus program. I want to define "E" as a constant value at each node in the part.

I have entered in inp. File

*Depvar

1,

*Elastic, dependencies=1

1000., 0.25, , 1000.

6e+09, 0.25, , 6e+09

*User Defined Field

and I have entered the constant values of "E" at each node like this .

*Initial Conditions, type=Field, Var=1

Part-1 . 1 , 22980538

Part-1 . 2 , 52880552

....... and all of nodes of the part

Moreover, I have defined a subroutine USDFLD as presented in this figure.

The problem is that after calling FV1 it is not equal to the values that I have interred in this command *Initial Conditions, type=Field, Var=1......How could I Solve this problem or is there any way to define "E" at each node of the part???

I am writing a FEA solver (using MATLAB) for computing stresses and stresses in a 2D rectangular plate with an elliptic hole (rotated to an angle). I computed the global stiffness matrix using Gauss quadrature (3 gauss points) and have also calculated stress and strain in each element.

How do I calculate the nodal stresses from the element stress values. I think the element stress values that I obtained are calculated at the centroid of each element. How do I extrapolate/interpolate these values to get nodal stress and strains?

Please advise with some resources or tutorials or solved examples.

Hi all,

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.

It seems that the most simple way to get both an infinite number of tessellated solids and lattices with periodic minimal surfaces in R3 consists on using a Pearce "saddle tetrahedron". The resultant convex solids:

1) Have configurations which tesselate the euclidean space. These tesselations are not Voronoi and have curved boundaries in a bcc lattice.

2) Define minimal surfaces for any 3 dimensional quadrelateral on the external closed surface of the solid.

Is there any topological description of such solids in the literature? How can we get a Weierstrass representation of the external surface of each polyhedron? How can we get the conjugate continous surfaces? Can we consider this to be a good design method for structural lattices?

Any comment will be wellcome.

Hi,

I would like to apply a defined value of initial stress on 3D Shell elements in the initial step in Abaqus CAE. These shell elements are connected to a 3D Deformable Solid by a Tie Constrain. I have also tried to connect them through "

*shell-to-solid-coupling*" constrain, but the same result. After the initial step, I provided a self-equilibrium step without any loading (**Figure 4**).My problem is that after the next steps when loading starts a fast relaxation of this shell element (

**Figure 1**) occurs without transferring the stresses to the tied 3D Solid shape (**Figure 2**). The tie properties are as shown in**Figure 3**.My question is how to transfer a prestressing load (predefined field: stress) from a shell element to a 3D Solid, tied to each other since the main reason for this prestressing is to provide a negative deflection in the main structure?

Abaqus provides the option to define the mode mix ratio based on energy or traction. The traction-based mixed mode response ( Mode I/II problem) where pure Mode I and II traction separation relation is already defined in the input file. Is the Abaqus interpolates for the intermediate mode mix ratios?

am working on static analysis on abaqus where friction coeff. is defined to be 0.01 and everything is going on well ....... on replacing the friction coeff. from

**0.01**to**0.3**the job is being aborted**even by changing the intial and minimum step time to EXTREME values .......**Any one had this problem before ???

I am looking to design and further running simulations and analyse a low speed shaft of a typical wind turbine. What should be the optimal shaft diameter and length for a given torque and rotational speed requirement in a transmission system of a wind turbine. Do you recommend any good software to run FEA simulations for validation analysis purposes.

Any suggestion, I will much appreciate.

I am looking to design and further running simulations and analyse a low speed shaft of a typical wind turbine. In particular I am looking to design the shaft diameter and length and any other connection components such bearings, keys and so on, for a given torque and rotational speed requirement in a transmission system of a wind turbine. Do you recommend any good software to run FEA simulations for validation analysis purposes.

Any suggestions or comments, I will much appreciate.

I cannot find the PLA material in ansys. I tried to add PLA in library. After that also it shows error in PLA properties.

Please tell the way to add the PLA, ABS in Ansys workbench.

Thanking you.

I am simulating the fatigue behaviour of Compact Tension (CT) samples using Ansys. I have to apply force which is calculated against any %UTS value it i cannot find which area will be used to accurately calculate the force for that ultimate stress value.

Dear sir or ma'am,

I am solving a 3D heat conduction equation involving a moving heat source (a laser). The goal is to get the thermal behaviour of the domain with time.

I am using structured grid and using the element size less than the dia of laser spot, which is way too small. It is computationally very heavy for my small laptop.

There is a method which uses adaptive moving mesh. A finer mesh surrounds the laser spot as it moves. But I do not have any idea how to implement that in my code.

Could you please recommed any thing where I can start? or how should I proceed?

Thank you and regards,

Ravi Varma

I get this error when I define material properties as nonlinear elastic

TB,MELAS

I cannot graph or plot the table.

I'm trying to simulate nonlinear compressive buckling of a material. However, it's not buckling as I would (theoretically) expect for lengths crossing the buckling threshold. It would just compress and fail at the failure strength/strain as specified in MAT024 - Piecewise Linear Plasticity. For further reference, I am using solid elements and it's a pin-pin configuration.

Theoretically, I'm thinking that a small lateral load/perturbation is needed to trigger the buckling and/or build the meshing with an out-of-straightness. I'm not an expert in FEA/LSDYNA, so any help with choosing the right keywords to get my specimen to buckle is appreciated.

I've already got the specimen to buckle elastically (eigenvalue), but struggling with nonlinear buckling.

Currently using Msc Marc Mentat for FEA. Now i conduct the mesh convergence/sensitivity analysis manually. So I need to know if there any automatic way to conduct the mesh convergence/sensitivity analysis

I am using bone model in finite element analysis. There are not many references that emphasize on how their mesh convergence analysis was done in detail. What I assume is by finding the max Von Mises stress on one simulation having element size of X, and redo the simulation with element size of X/2 and get another max Von Mises stress. I'd do it repeatedly until X/16.

But is my assumption already correct? Or should I use something like root mean square calculation?

Greetings to all.

I am trying to simulate heat transfer between 2 parallel plates.

The source plate have heat condition and I want to get temperature profile in upper plate, where heat flow through convection between the two .

Can someone assist me with some tips?

I am an undergraduate student doing a thesis regarding slope stability analysis using PLAXIS 2D. My study area is at Kajang, Malaysia. I only assumed the phreatic water level because I don't have any borehole data. I have already done the model but I have questions regarding my model:

1. Is the water level that I have marked and assumed logical? (40 m above flat land)

2. What does the legend on the right represent, and is it the FOS? (The FOS that I obtained from the model is 1.780 as shown in the picture below)

3. Is the part that I have marked in the picture the critical slip surface (Picture 3)?

Thank you in advance for your help.

I have applied load axial to the column and pressure at beam but when i am try to plot x y data the reaction forces are zero at every node whereas in legend the reactions forces are showing.

#abaqus #FEA

I am attempting to model a pretensioned concrete beam in ansys by varying prestressing force along the Straight Pre-Tensioning Strand.

During the experiment, the beam was fabricated segment by segment. The applied prestress was then released decrementally after each concrete segment.

The results of the distribution of prestress should be similar to the attached Figure 1.

However, in the finite model, the beam model is already been fully constructed.

I am trying to consider the prestressing force as push in pressure at the both ends of the strand.

Hence:

How do vary the pretensioning force for each concrete segment ?

If possible, please help me to provide some background source.

Thanks

I exported the global stiffness matrix for my linear elastic instance in Abaqus, by attaching the following commands to the input file:

** Output Global Stiffness Matrix

*Step, name=Global_Stiffness_Matrix

*MATRIX GENERATE, STIFFNESS

*MATRIX OUTPUT, STIFFNESS, FORMAT=MATRIX INPUT

*End Step

However, the resulting matrix has most of the diagonal elements with very large values, for example:

1635,3, 1635,3, 1.000000000000000e+36

Why is this happening? And how could I solve?

Thanks!

Hello,

Recently, I am learning how to develop a full microstructure-resolved 3D model. And I want to use X-ray nano-tomography or focused ion beam/scanning electron microscope (FIB/SEM) to reconstruct the microstructure of commercial electrodes with sufficient nanoscale details. The microstructure-resolved models can be imported into computational programs to mimic the electrode behavior under the battery operation condition. But I encountered some questions. Firstly, how to add the current collector and separator into the segmented volume to construct a battery half-cell? Secondly, how to export the battery half-cell and import it into computational programs like COMSOL? Does any examples or source code about these questions?

I would appreciate it if you can help me.

Hello. I am working on a project that investigates the stresses in severe scoliosis. Unfortunately, severe scoliosis has not been studied much using FEM. Can you help me to find the suitable

**Loading**and**Torque**for the situation when the cobb angle is**greater than 40 degrees**? Or to Recommend me an article that has good information in this field.Thank you so much for your attention and participation.

Help i am getting the following error message in abaqus

**WARNING: Surf-1 is ambiguously connected at node ###.
This surface cannot be used with *CONTACT PAIR.
***ERROR: 1 improperly defined surface(s). Please check your surface
definitions. Make sure that all surface normals point outward.

Note:

The mesh is an orphan mesh and is generated outside ABAQUS.

The mesh is fine and has a huge number of elements.

Element typr for the mesh is C3D4

i have defined the surface using ABAQUS CAE and it was generated automatically using the following commands

*elset, elset=surf-1-S1-1

*elset, elset=surf-1-S2-1

*elset, elset=surf-1-S3-1

*elset, elset=surf-1-S4-1

....

*surface,type=element,name=surf-1

surf-1-S1-1,S1

surf-1-S2-1,S2

surf-1-S3-1,S3

surf-1-S4-1,S4

As you will see, i have followed section

**2.3.2 Element-based surface definition in abaqus user's guide.****if you read "**Creating surface facets by specifying solid, continuum shell, and cohesive element faces" you will see i have followed it.

So what is the issue here?

I have created a solid mesh of a flange model in hypermesh. However, only one of the mesh quality criteria is not satisfied. The max angle of some hexahendral elements is slightly higher than 135° (136°). How can this affect the final results?

Note: aspect ratio, jacobian, warping angle,skewness are fine

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.

If there is 2 DOF (Translational, Rotational) Cantilever beam, and it has 7 elements, I want to use System reduction technique to get rid of the rotational Dof, Do I expect to obtain the same first seven natural frequencies?

Because I tried to use SEREP technique and I did not get the first seven natural frequencies, I got the 1,3,5,7,9,11,13 natural frequencies?

Does anyone has explanations please?

FEM modelling software such as ANSYS, MATLAB, OpenSees, and Abaqus are available. Similarly, I'm looking for FEM software that could be used to analyze air pollutant dispersion. Is there anything such as this available?

Hi there,

I am starting to learn finite element analysis. I am basically doing research on large scale landslide. I am willing to learn the modelling of soil nailing by using the finite element analysis. Can you please suggest me some research works and books so that I can get some help. I will ABAQUS for FEM.