== Problem Description ==

The failure index and strength ratio of a honeycomb sandwich plate under the biaxial loading condition are predicted using the MSG plate model. For a plate structural analysis, the loads are usually expressed in terms of plate stress resultants {N11, N22, N12, M11, M22, M12}. In this example, N11=N22=10 N is assumed.

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== Software Used == 

[https://cdmhub.org/tools/scstandard/ Gmsh4SC 1.6.5] [[BR]]

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== Solution Procedure == 

Below describes the step-by-step procedure you followed to solve the problem. [[BR]]

=== 1. step 1 ===
 * Open Gmsh4SC and create a new model (Change the default name). Click Material->Thermoelastic and input the matrix and fiber properties as shown in Fig. 1 and Fig. 2. [[BR]]
 [[Image(Gmsh2_1.JPG, 800px)]]  [[BR]]
 Fig. 1 [[BR]]
 [[Image(Gmsh2_2.JPG, 800px)]]  [[BR]]
 Fig. 2 [[BR]]
* Click Geometry->Common SG->3D SG->Honeycomb. Select the materials for core and skim as shown in Fig. 3. [[BR]]
 [[Image(Gmsh2_3.JPG, 500px)]]  [[BR]]
 Fig. 3 [[BR]]
* Click Mesh->Generate 3D mesh->Generate (Fig. 4.). [[BR]]
 [[Image(Gmsh2_4.JPG, 500px)]]  [[BR]]
 Fig. 4 [[BR]]
* Click SwiftComp->Homogenization->Plate model. Keep the default parameters and click save and run. The homogenization results will automatically pop up (Fig. 5.). 
 [[Image(Gmsh2_5.JPG, 800px)]]  [[BR]]
 Fig. 5 [[BR]]
=== 2. step 2 ===
* Click SwiftComp->Static failure->Input failure constants. Assign failure criterion (max-stress) to the core first (Fig. 6.) and input the failure constants (Fig. 7.). Repeat this step to define the fiber failure constants as shown in Fig. 8 and 9. Note that the lam is non-isotropic material and we will use Tsai-Wu failure criterion in this example. [[BR]]
 [[Image(Gmsh2_6.JPG, 400px)]]  [[BR]]
 Fig. 6 [[BR]]
 [[Image(Gmsh2_7.JPG, 600px)]]  [[BR]]
 Fig. 7 [[BR]]
 [[Image(Gmsh2_8.JPG, 400px)]]  [[BR]]
 Fig. 8 [[BR]]
 [[Image(Gmsh2_9.JPG, 800px)]]  [[BR]]
 Fig. 9 [[BR]]
* Click Failure index and strength ratio and select stress-based failure criterion. Click add. Select plate model and input and loads as shown in Fig. 10.
 [[Image(Gmsh2_10.JPG, 600px)]]  [[BR]]
 Fig. 10 [[BR]]
* Click Run. The contour plots of the failure index and strength ratio under this loading condition is given as shown in Fig. 11 and 12. [[BR]] 
 [[Image(Gmsh2_11.JPG, 500px)]]  [[BR]]
 Fig. 11 [[BR]]
 [[Image(Gmsh2_12.JPG, 500px)]]  [[BR]]
 Fig. 12 [[BR]]