All Questions
18
questions
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20
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Seeking Advice: Improving Resin Application in Honeycomb Lamination for a Sustainable Project
I am trying to laminate a honeycomb structure with a fiberglass and resin reinforcement. However, I have problems because a large amount of resin falls through the holes of the honeycomb and the final ...
- 1
0
votes
1
answer
48
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Why the size of top and bottom rollers is different in three point bend test?
In a short beam shear testing of polymers, the configuration is such that the top (loading) roller is bigger than the bottom (support) rollers. Why is this the case, and what happens when the size of ...
- 1
0
votes
1
answer
189
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Why don't people use sodium silicate to bind fiberglass instead of epoxy?
I tried to search for it, but I couldn't find any answer on the subject. I could only find that water glass is normally used mixed with other stuff like sand to make casting molds.
In my mind it would ...
- 51
1
vote
0
answers
18
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why did my ceramic matrix composite turn out brittle as snow?
I have attempted making a ceramic matrix composite (cmc) by wetting glass fiber cloth with waterglass and baking it at 200°C. The resulting material disintegrated on touch. Unwetted fibers did not ...
- 378
-1
votes
1
answer
55
views
How to know the material of key-top?
There are keys (push buttons) on the front panel of an avionics device that fits inside the aircraft cockpit. I need to know the material of which those key-tops are made from.
I can guess the ...
- 109
1
vote
0
answers
328
views
How can I calculate the shear modulus (Gxy) for the material of a composite laminate [10/-10/-10/10] using test data?
I have the data from a tensile test including axial displacement, force, and strain, as well as E1, E2, Nu12, and Nu21 for the carbon fiber prepreg. I am trying to use this axial data to calculate Gxy ...
- 11
0
votes
2
answers
170
views
What are equations related to the compaction of composite metal powders?
Say I am trying to create a metal composite and have a mixture of 3 different metal powders each with varying weight %'s. I'm going to compact them into the shape of a ring by applying a force P. The ...
- 15
-1
votes
1
answer
107
views
Why do people build the core of a sandwich structure using composite
Usually I see composite as a laminate wrapped around the core of a sandwich structure. Usually in loading such as bending the bending stress is the highest furthest away from the neutral axis, while ...
- 1
0
votes
0
answers
65
views
Buckling of composite plates help
I am trying to write code for the buckling of composite plates using the Ritz approximation but I can't understand something. According to Reddy (Mechanics of laminated composites), this is the ...
1
vote
2
answers
231
views
Young's modulus for composite auxetic material
If you look at the screenshot you will see a composite auxetic material. How would you calculate the E-modulus for it? Is it as simple as the rule of mixtures, ...
- 145
2
votes
2
answers
2k
views
Can we make engineering grade paper mache by improving on the paper?
Can we bring engineering to the paper in paper mache? It's a mix of a binder and a reinforcing matrix. PVA is common for the binder and is strong. That's fine as I think it's strong enough and ...
- 916
2
votes
3
answers
532
views
Can you postcure epoxy composites outside the mold?
Say I make a fiberglass/epoxy part on a plastic mold, and it cures at room temperature. The epoxy system calls for a postcure at 250F, but the mold cannot withstand 250F.
If I take off the part and ...
- 23
1
vote
1
answer
213
views
Design a composite material with good wear resistance and electrical conductivity
For a electrical switching device which opens and closes frequently and forcefully. Would a combination of a soft polymer matrix and a conductive metal fibre be a good choice for this? While polymer ...
- 201
4
votes
1
answer
925
views
How do I cut a crack into a polymer/plastic?
We need to cut a very thin crack into a polymer plate for a research project. The closest thing to what we are looking for is Wire EDM but since the polymer we are using is not conductive we cant use ...
- 147
1
vote
2
answers
8k
views
How do I calculate the structural properties of a fiberglass laminated wood panel?
I'm constructing 2.2 meters span, 1 m wide shelf. Want to make it cheap but thin.
I'm planning to use 18mm thick OSB board and reinforce it with a layer of stronger material stuck to it's bottom.
My ...
- 163