What is Fea: Definition and 123 Discussions

Hi, I am a newcomer to FEA/FEM. I am aware that for any practical purpose, software is used to solve problems. However, before I utilize software, I want to understand the process the computer goes about doing. This document is simply an attempt to summarize the solving procedure in a concise...

I'd like to calculate the whole structure including welded beams and then calculate rails and the beam used for suspend a robotic arm. The problem is I've no idea how could I start. I was trying to find some training materials (mainly books) on this topic (design of supporting structures for...

Hi, I'm working on a simple FEA involving a preloaded bolt: The bolt is modeled as a single part (shank + head + nut), glued (perfect bonding) to both rings. Pretension force ##F_{preload}=200 \ N## is applied in the first step of the analysis while in the second, pretension force stops...

Hi Im slightly stuck not sure what i put is ok. FEA was used to carry out analysis on 3 structures and diagram results obtain (no data) Explain where the first point of failure is likely to originate, and why. An analysis of the studies, do you think that they will be an accurate...

Hey Im doing FEA and got stuck on question. The diagram go me stuck, because looking through the workbook it says high stresses are in red and low in blue, whereas they included both different kind of stresses on the same diagram and no data. Note: High Compressive strains are noted by blue...

This is a bit of a multi-part question on impact engineering and FEA usage. I am working on making my Alumina ceramic model as accurate as possible in ANSYS for impact simulations. But I am noticing a common theme, while using model parameters in scientific journals I am not getting any...

As is well known, the stiffness of an FEA model decreases with a refined mesh. What's the rigorous derivation of this?

A PDE is solved by finite elements. The PDE then becomes a discrete system solved by Newton iteration. Every iteration step comes with a residual error. When the solution is completed, how far is the residual error of the PDE from the residual error of the finite element discrete system?

Hello, so recently I have been doing one preetty simple project in FEA, my task was to do a front impact analysis on go-kart chasis. While the simulation itself isn't hard at all and to be honest I had easy job thanks to various sources of tutorials around the web, I feel like I don't understand...

Hi all, Sorry of this is a silly question but it is one that recently came to mind and I cannot seem to find an answer to it: "should I change my mesh depending on the type of FEA analysis I am doing?" My feeling is that I should not change it, but that is a total guess on my part. Any...

I'm building a computer that I'll be using primarily for FEA. No games. I'm leaning towards the Ryzen 9 5950x. I have a budget up to $1000-ish +200 maybe for the CPU. That will hurt seeing how I'm considering a $750 CPU (5950x), but I'd be willing to if need be and the gain is significant...

Hi all, I’m trying to get a better understanding of ANSYS as I don’t have a lot of experience with it. My question is with respect to a static structural analysis of a solid part: “how can I be reasonably confident that FEA is giving me reasonably accurate stress values?” I’ll analyse a...

For a 2D problem with unknown displacements u(x,y) and v(x,y), is it allowed to give such a set of BCs u(0,y)=1 and vy(0,y)=0, the former being a displacement BC, the latter being a force BC (vy is the y strain)? How is this implemented in FEA software?

I would like to solve a coupled system of two PDEs using Comsol for the following geometry: Equation 1 (valid for 0⩽Z⩽bm): The initial and boundary conditions are: Tm(r,t→0)=20 Tm(r→rw,t)=70 Tm(r→∞,t)=20 However, for bm⩽Z⩽bm+b2, the equation to solve is: With the following initial and...

Hi, solid elements used in FEA don't have rotational DOFs so normally it's not possible to read the angle of twist from simulation involving torsion. Some programs allow the transformation of results to cylindrical coordinate system but it's not always the case. From what I've heard, it's...

I'm new to composite materials. I've studied mechanical engineering but I am actually usually involved in hydrodynamics (in which I've done my masters). However for a project we do fluid structure interaction with composites, and as these things go, you cannot get away with the 'black box'...

Hi, 2 part question trying to get tetrahedron Finite Element shape functions working: 1) How do I properly setup the shape coefficient matrix and 2) How do I build the coefficient quantities in the shape functions properly? ANY tips or corrections may unblock me and would be of much value...

This is the analytical working out. I substituted the value of 306mm ( the maximum length of the beam) to find the maximum deflection along the Z-axis. Which came out to be -2.39mm. But according to Ansys the average deflection is 0.3mm and the maximum deflection is 0.8mm. This is the Ansys Values.

I'm making a custom wrench for personal use. For fun, I'd like to run an FEA and see if the wrench will fail. Below is a similar wrench. 100ft-lbs are applied with a torque wrench to the square socket. Where do I fix and apply the load? Should it be a torque or a force? I'm doing the FEA in...

Hi, advanced FEA programs allow their users to perform fatigue analyses. However, there are still many programs where such simulations can't be performed. I've heard that in such case one can use results obtained from regular linear static FEA to calculate fatigue life manually. Theoretically...

Dear FEA experts, I'm trying to model the mechanical behavior (static, modal, and buckling analyses) of an underwater floating structure (e.g. submarine capsule or buoy) under hydrostatic pressure by Finite Element Analysis. To obtain feasible results, the structure should be modeled as freely...

Hi, I want to model the phenomena that a windshield gets covered in ice during a night with clear sky even tough the air holds a temperature of a few degrees above zero Celsius (at which water freezes for sea level pressure). Clearly the windshield gets a temperature below zero Celsius, and...

I am a mechanical an engineer with a few years of experience. Most of the work I do is transient, structural finite element analysis. I have gotten reasonably competent at building models and pumping out results, but I regularly come across gaps in my fundamental knowledge. I have been doing...

Hi, it's been a while since I last posted. Anyway, so I went through the trouble of enrolling in two finite element analyses classes and yet, they still don't teach how the 2D formulation has been made. I'll list the things that 'I know' already to get some things clear. I know how to derive...

Hi PF! I am solving ##\nabla^2\phi = 0## in Mathematica via NDSolveValue. Rather than waste your time explaining the 2D domain ##\Omega##, check out the code at the bottom of page (copy-paste into Mathematica). Specifically, I am enforcing a Neumann BC on the curved boundary ##\Gamma## through...

Hi, I am facing issues with my program. Listed below. This is form my masters project. Also in what way can I connect the filleted surfaces shown in fig by a weld or just load or stress transfer connection. fini /clear /title,C160T2B70-1L /prep7 et,1,shell181 r,1,2 mp,ex,1,1.85e5...

Hi PF! Can someone help me understand the difference between interpolation order (linear, quadratic, etc) vs element number? Like, if we had a 1D beam (for simplicity) what's the difference between using 1 element and a quadratic interpolation vs 2 elements but a linear interpolation? Not...

Hi, I'm trying to do some stress analysis on a tank filled with water, I have split the walls into sections and applied the appropriate pressures. However, I'm confused as to whether I apply the weight of the water+pressure at that height difference to the bottom of the plate; or will the...

Hello, Does anyone know if a finite element skeleton source code exists. Finite element can be used for structural memebers, gas dynamics, etc. But the over all stepping software is the same and then just input the core equations. My application is for pseudo one dimensional compressible...

Hi all, I have performed a small static analysis with one element (C3D8). The bottom face of element is completely constrained, and the top part is displaced. In the geometrical linear analysis, the internal energy (ALLIE) and the work done (ALLWK) are equal. So, with ETOTAL = ALLIE - ALLWK...

Hi, Im wondering if / how commercial FEA codes take into account additional unbalance forces due to the off-axis displacement of masses. For instance, if I am modeling a jeffcott rotor with an unbalance, I would traditionally represent this unbalance with a force that increases with speed^2...

Hi all, I have some doubts regarding the strain tensors Abaqus uses for the case of Geometrical non linear analysis. In the case of geometrically linear analysis, all the strain tensors will be equal to engineering strain, So it doesn't matter which strain tensor Abaqus uses. But for...

Hi all, I have a personal project I am working on in Abaqus CAE/Explicit 2017. I have a tube, that I am trying to advance into a larger tube with a bend in it. The idea is that the small tube enters and then deforms around the bend as it comes into contact with the radius of curvature of the...

I am trying to simulate a linear eddy current brake. To do this, I am modeling my brake as a single magnet moving above an aluminum plate. I plan to measure the drag force on this magnet and calculate my braking force as a superposition of single magnets. Here's my current setup: Model: A...

I am doing FE analysis for symmetric shape in boundary conditions and geometry, I would like to know if I can use symmetry in my analysis or not. I have tried to run trials, the results are very similar but I am not sure if this just a coincident

Hello, I have a fairly simple question but I guess I am having a hard time trying to understand it. I have a plastic connection of two different geometries (see attachment). When I hold end of the front portion (of the uniform diameter) and apply torque at the bigger cylinder geometry, there...

Hi,I have been reading a text on "Finite Element model updating". This question is not related to the subject of "Finite Element Model Updating" but rather to the subject of "Structural Dynamics" and experimental modal analysis. My questions is: 1)Let us say I have carried out a free...

I'm working on a question which asks to determine the deflection, curvature, forces and moments of a simply supported beam with a distributed load. diagram shown in here http://imgur.com/a/wpI4kInitially, I've done the calculation with 1 plane beam element with 2 nodes. At L = 0 and L = 3. But...

Hi everyone! I am a soon-to-be graduate of the Technical University of Munich and work in the field of Computer-Aided Engineering (CAE) – looking to exchange experience and ideas on CFD, FEA,Thermal Analysis and their applications in product design!

Hello, I am doing a project which includes attempting to map a theoretical pressure distribution across a capillary tube. I am trying to do a finite element analysis using Hagen-Poiseuille's Law to map the theoretical pressure distribution before I move onto using a SolidWorks Flow Simulation...

I have ran an FEA analysis on part screenshot below. I wanted to do some hand calculations to validate the results. What formula should I use to calculate the stress?

Hello, I want to ask how I want to make a rotation using angle in Ansys Workbench ? I already read some suggestions that it can be done by using local coordinate system but unfortunately I can't done it right. Is there any youtube video or tutorials that I can refer ? I hope someone can help...

When choosing between a 2D 4-node quadrilateral element and 8-node for FEA stress analysis, why is the 8 node option preferred? I understand it has much more flexibility with different shapes due to the central mid node but are there any other reasons?

Hi, I am a bit confused. So I have a shaft with a step on both sides so it gets really large in the middle. I am trying to model torsion on the rotor of a BLDC motor with FEA (or by hand calculations). If I apply a moment on the sides and fix the faces at the end of the shaft I get 1 result...

Hey everyone, I've started to do research for my undergraduate thesis topic and I would like to use FEA with an application to quantum computers. I'm thinking of something in regards to mechanical vibrations, however I'm open to consider anything given it's possible at the undergraduate level...

So I am planning on doing an FEA for a rotational component as part of university project. I am fairly confident about the analysis itself, meshing, convergence, etc.. I feel I am capable of setting up an accurate model. However, I need to validate my study with a simple preparatory FEA which...

Greetings to all, I am doing FEA analysis of a jib crane. I am using Autodesk Inventor. The results show that the max Von Mises stress in the support pin is 773 MPa. This value exceeds the yield strength of the Carbon Steel. Does this mean that the Pin will fail under load ?

Why do axisymmetric FEA models of magnets and their fields make the field farther from the axis appear denser than it really is when the flux line mode is enabled? I'm using the F.E.M.M. system at the moment. All integrals and graphs give correct values, but the depicted lines of flux appear...

Hi all, Can anyone point me to a quantitative explanation of the geometric multigrid and Vanka smoothers? I found a qualitative article describing the GMG smoother, but it doesn't quantify how much it reduces the cost of a problem. I have found nothing yet on the Vanka smoother except that it...

Hi, My name is Gordon Mutten. I have been a stress engineer for 40 years working on aircraft, spacecraft , and several other products involving metals and composites etc. I would like to offer my help with simple stress analysis questions. I am soon to start a website for this subject so I...