Composite sandwich products loaded in bending tend to fail by buckling of the laminate under compression. The author’s intuition is that corrugating the surface under compression should help. So the question is; does it help, and how much. That is what will be investigated in this article.
Articles tagged with "FEA"
linecommand in CalculiX Graphics can create lines, arc and splines but not elliptical arcs. This article describes how to approximate elliptical arcs using splines.
In this article the difference in the images of the stresses between a quadrilateral hexahedron (“hex”) mesh and a tetraeder (“tet”) mesh will be investigated. In both cases, second order elements will be used.
Hopefully this will make it clear to the reader why hex meshes are generally preferred.
The way FEA works can lead to concentrations of high stress in single elements or even nodes. This article aims to show how such singularities can be recognized and when they can be safely ignored.
Honeycomb cores are often used in composite structures as an alternative core material to e.g. polymeric foams or end-grain balsa.
In FEA we want to be able to treat honeycomb as a continuous material instead of having to model individual cells. Otherwise even simple FEA models involving honeycomb would become unmanageably large.
My CalculiX projects are all kept in their own directories. In each of those directories there exists a
Makefile. This contains instructions for the make program.
By default, invoking
makein this directory runs the pre-processor and the solver. But there are also specific sub-commands, for example:
- “make mesh” shows the mesh used in the FEA.
- “make disp” shows the deformed product in the post-processor.
- “make stress” shows the stresses in the product in the post-processor.
Recently I was looking for material data for 60 Shore A rubber for a simulation. This article describes what I found and how I transformed that to material data.
This is the second part in a series how to analyse sandwich structures with FEA. The first part is here. If you haven’t done so, you should probably read that first.
In that part we built and analyzed a sandwich where the core and skins shared nodes. We saw how that leads to incorrect stress distribution images because of nodal averaging. In this article, we’re going to fix that by using
This is the first part of a series of articles where I hope to show how to analyze deflection and stress in structures using the free CalculiX software. I’m using version 2.17. The focus will be on sandwich structures because that is the area in which I’m most interested. Compared to parts consisting out of a single material this is a bit more tricky as we will see in this article. The main reason for using finite element analysis (“FEA”) in general is that it allows for complete analysis of problems where no integral solution exists.
Additionally, some of the assumptions used in Euler–Bernoulli beam theory for analyzing deformation and stresses in beams and plates do not hold for sandwiches.