# Tag Info

Accepted

### Deflection of thin plate with 1 free edge and deflection > thickness

You are correct that this problem falls within the category of 'large-deflection' problems since the deflection is larger then about $\frac{t}{2}$. To correctly analyse a plate under large-deflections ...
• 2,641

From a theoretical standpoint, the displacement gradient is equivalent to strain (assuming a structural problem). Numerically, you can obtain the derivate of a quantity through multiplication with ...

### Negative Eigenvalues in Ritz Solution of First-Order Shear Deformation Theory

The only way you can get negative eigenvalues is by including stress stiffness effects (sometimes called "geometric stiffness"), if there are compressive stresses which would cause the plate to buckle....
• 12.5k
Accepted

• 1,443
1 vote

### How to code this iterative scheme for solving 2-group diffusion equation?

You haven't given enough information to answer this exactly, but I am assuming from your equations that you are solving mesh-centered equations and the assumption is that the flux is linear in each ...
1 vote

### Implicit and Explicit finite difference discretization of steady state heat conduction equation

A non-iterative solution for steady-state heat flow must be implicit. You are solving for the temperatures "everywhere" in the structure in a single "step", so every boundary condition must affect the ...
• 12.5k
1 vote

### Calculate surface area and outward normal of each face(non-planar) for a irregular hexahedron.

If the surface is nonplanar then the surface normal is a (hopefully continuous and differentiable) function of location. You will have to integrate the surface function S(x,y,z) over any two of the ...
• 4,229
1 vote

### Temperature not changing in my code for 1-D heat equation: Explicit Scheme

This stackexchange doesn't really seek to solve these homework-like problems directly. However, I can offer some hints on how to proceed. Are you sure the scale of ...
• 4,061
1 vote

### Example of real-life problem solved with numerical methods?

You could develop some saturated steam equations by running a regression on steam table data. Even if it was a giant equation, sure would be nice to not have to do a a table lookup in an otherwise ...
• 8,181
1 vote

### Mechanical Engineering- Modeling contact in Abaqus

There can be thousands of causes for your error. You need to give many more informations to be able to make a guess. Like: discretization, solving methods for the DEQs, grid topology, boundary ...
• 223
1 vote

### J2 orbit propagation problem in MATLAB (solver instability)

https://www.mathworks.com/matlabcentral/fileexchange/55167-high-precision-orbit-propagator?s_tid=srchtitle https://www.researchgate.net/publication/340793133_High_Precision_Orbit_Propagator_C_code The ...
1 vote
Accepted

### J2 orbit propagation problem in MATLAB (solver instability)

Solved it, thanks to a colleague. The problem is, I used "J2 Propagator" in STK, which in fact uses secular rates of orbital precession. Comparing that result with the real integration that MATLAB ...
• 31
1 vote

### J2 orbit propagation problem in MATLAB (solver instability)

As far as I can see, you are trying to integrate a nonlinear ODE of a conservative system. It is very likely that your system exhibits chaotic behavior. RK4 is a fourth order numerical scheme. These ...
• 1,036
1 vote

### Deflection of thin plate with 1 free edge and deflection > thickness

The small deflection approximation is not based on deflection vs thickness, it is based on deflection over span. So for your maximum case of 10mm deflection on a 1250mm span, you are only looking at a ...
• 111
1 vote

### Normalization and Non-Dimensionalization of a mass balance equation

Sorry with not being familiar with all of your variables. If it is a mass balance as you say, then you can't get a Reynolds or Péclet number. A Reynolds number appears in the dimensional analysis of ...
• 679
1 vote

### External diffusion: calculation of surface concentration

The way you have solved your problem you have treated the concentration at the surface of the sphere as known ($y_{B,\text{surf}}$). Notice that in your final answer, if you plug in $r=r_\text{sphere}$...

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