Scan&Solve™ operates under the assumption of linear isotropic materials. Materials that are “linear” have a proportional relationship between stress and strain. That is, any increase in strain results in a proportional increase in stress, and vice versa. Materials that are “isotropic” possess the same mechanical properties in any orientation.

Scan&Solve™ supports the following failure criteria:

• Von Mises -used for ductile materials.
• Maximum Shear Stress -used for ductile materials, it is also known as the Tresca or Guest criterion and is slightly more conservative than the von Mises criterion.
• Rankine -used for brittle materials, it is also known as maximum normal stress criterion.
• Coulomb Mohr -used for brittle materials, more conservative than Rankine criterion.
• Modified Mohr -used for brittle materials, more conservative than Coulomb Mohr criterion.

Scan&Solve™ computes the Danger Level in the [View] tab based on the Yield Strength, Tensile Strength, and Compressive Strength specified in the material database. The von Mises and maximum shear stress failure criteria are only applicable to ductile materials- materials that flex, stretch, or compress significantly before failure. The Rankine, Coulomb-Mohr, and Modified Mohr failure criteria must be used for brittle materials such as glass, ceramics, and concrete- materials that fail without significant deformation.

Different failure criteria may be selected when editing material properties. When editing, the von Mises and Maximum Shear Stress criteria require a positive yield strength to be specified. The Rankine, Coulomb-Mohr, and Modified Mohr criteria require positive tensile strength and compressive strength entries.

• Materials and Failure Criteria