To check the solidity of your model, select "Solidity Check" instead of "Default view" in the lower right corner of the viewer 3D. This functionality is made simple to use thanks to a visual color code from green (good) to red (fragile), illustrating the strength of the 3D object.
The automatic tool Sculpteo strength verification allows you to observe and verify the risk areas before printing. If it's green, you can print without risk. Otherwise, you should try to print in another size or a different material.
This tool is dynamic: if you change the material or the size of the 3D printing, the strength test will change accordingly. This allows you to adjust the ratio of your size-strength-material.
You can see the minimum recommended thickness on the lower right-hand side of the solidity check; the minimum thickness will also change when the material is changed.
If you want to know the thickness of a fragile area, you can use the cursor and then the left-hand click of the mouse over the weak areas, and the thickness will be shown: