# Tag Info

### What is the difference between FEA and CFD?

CFD (computational fluid dynamics) includes any numerical method used to solve fluid flow problems. FEA (finite element analysis) is one numerical method for solving partial differential equations, ...
• 12.6k
Accepted

### What is the physical interpretation of the eigenvalues of the stiffness matrix in the finite element method?

Assume a 1d version of the equation. Then the K matrix becomes a k, spring constant. In 1-D The equation reduces to : $m \ddot{q} + kq = f$ The q matrix also becomes x vector in one dimension. ...
• 906

### Why doesnt steel melt when pouring titanium through it

Firstly you're mixing units The melting point of titanium is 1668C (3000F) The melting point of steel starts at around 1300C up to around 1500C depending on carbon content. For brief contact ...
• 15.2k
Accepted

### FEM - is symmetry a boundary condition?

The symmetry itself is not a boundary condition. It is a property of your system which means that both the geometry and the load are symmetric with respect to an axis or a plane. It allows to reduce ...
• 174
Accepted

• 13.1k

### FEM - is symmetry a boundary condition?

Symmetry is used to reduce the size of the object and therefore the mesh or allow more mesh to represent that reduced object. So the “cut plane” of symmetry is not a boundary where the material ...
• 15.9k
Accepted

### Representing slabs in FEM

The general rule of thumb is never to introduce a degree of complexity you don't need. Use the expected behaviour of the structure to determine the element type. A two-way slab is usually best ...
• 1,288

### Is the compatibility condition based Cauchy-Green strain used in FEM

The reason the compatibility equations are important is to ensure that the displacement of the structure is physically sensible, for example the deformed shape can not contain "holes" or ...
• 12.6k

### Stress Concentration Factor – Why a Specific Range?

From what I see, in this picture from the Shigley book, if I really had to, I would extrapolate to 0.5 (or more precisely interpolate between the limit cases). The limit cases for very thick plate (d/...
• 24.4k
Accepted

### Computing the stress field of a structure made of 4-nodes shell elements (accounting for membrane action, bending and shear)

Here be dragons. Or, to paraphrase a hadith of the Prophet Mohammed, "There are seventy ways to compute element stresses, and all of them are wrong." The naive approach is to differentiate ...
• 12.6k

### Boundary condition at supported end of a rod

None of the three would occur if the material of the element holding the rod is "rigid", or is much stiffer than the rod. For such cases, my assessment is as shown below. For the case that ...
• 8,247

### What is stress stiffening in Finite Element Analysis?

My undestanding is that stress stiffening is the additional stiffness in structures when there is an applied prestressed state. The most common example, -I know of- is how the guitar string (or a beam)...
• 24.4k

### What is stress stiffening in Finite Element Analysis?

Stress stiffening is the work done to displace the structure that is caused by its internal stress. The simplest formulation of FEA (and classical theories like Euler-Timoshenko beam theory) assume ...
• 12.6k

### Why is my FEM analysis producing unusually-large stress results?

First of all, whenever I see stresses so localised near the boundary, I always think that there is something wrong. IMHO, the max stress at corner is an artifact, probably due to overconstraining the ...
• 24.4k

### When a jet engine propels an aircraft forward, where does the thrust force on aircraft act?

The thrust force acts on the axle bearings that support the compressor stage shaft of the turbine. That reaction force is conveyed out to the engine mounts which are in turn bolted to the airframe.
• 15.1k

### When a jet engine propels an aircraft forward, where does the thrust force on aircraft act?

I think the thrust is generally applied as show on the top part of the following image. If you are trying to apply the force on the mount, then the same force is applied, however you need to add a ...
• 24.4k