FEA Simulation for ASTM C393
ASTM C393_Standard Test Method for Shear Strength
*work in progress*
Intro
This page will show the simulation results for a 3-point bend test on 75 x 200 mm sandwich construction with various core thicknesses. The purpose of this test is to obtain the compressive strength and from that compressive strength, calculate shear strength. We will use the results from this simulation to compare with our in-person results to see if they conform to our standards.
Stackup:
The test specimen I used was a sandwich of a top layer using 3 layers of 0.15 mm prepreg, a 1 inch, 1/2 inch, or 1/4 inch Nomex and a bottom layer again using 3 layers of 0.15mm prepreg.
Figure 1: Picture of the test specimen with fibre directions
The loading condition:
For this simulation, I used a nodal force of 1000 N downwards on the top face. There are also fixed supports on both ends of the specimen, on the bottom face.
Figure 2: Loading and Boundary Conditions
Figure 3: Deformation of sandwich construction (1/4 inch core)
Results:
Specimen | Maximum Deformation (mm) |
---|---|
1/4 Inch Nomex | 1.2 |
1/2 Inch Nomex | 0.58726 |
1 Inch Nomex | 0.27903 |
1/4 Inch Nomex
Sandwich Layer | Minimum Stress (MPa) | Maximum Stress (MPa) | Notes |
---|---|---|---|
Top Layer | -79.27 | 67.87 | Averaged value |
Honeycomb | -0.0015432 | 0.0014185 |
|
Bottom Layer | -64.94 | 76.18 | Averaged value |
1/2 Inch Nomex
Sandwich Layer | Minimum Stress (MPa) | Maximum Stress (MPa) | Notes |
---|---|---|---|
Top Layer | -40.422 | 34.893 | Averaged value |
Honeycomb | -0.00082218 | 0.00076126 |
|
Bottom Layer | -34.106 | 39.51 | Averaged value |
I Inch Nomex
Sandwich Layer | Minimum Stress (MPa) | Maximum Stress (MPa) | Notes |
---|---|---|---|
Top Layer | -20.348 | 17.697 | Averaged value |
Honeycomb | -0.0004234 | 0.00039471 |
|
Bottom Layer | -17.492 | 20.113 | Averaged value |
Below is a table of where the stresses occurred in the 1/4 inch Nomex
Layer | Stress |
---|---|
Top |
Comment: Max stress of 64.94 MPa on red area. |
Middle | Comment: Max stress of 0.0014185 on red area. |
Bottom | Comment: max stress of 72.423 MPa on red area. |