Stress in second principal direction result

The Stress in second principal direction result shows the second principal stress in the part (Warp or Stress analysis), or in the wire or paddle (Microchip Encapsulation analysis), at the selected layer through the cross-section, after ejection.

Positive values correspond to tension in the part, and negative values to compression.

Note: This result is only available if you have selected an appropriate option in the Stress result(s) to output drop-down menu in the Process Settings Wizard.

Note: The direction of the second principal stress (minimum normal stress) on the top/bottom of each element is perpendicular to the direction of the first principal stress.

Using this result

Consider the second principal stress when the material is brittle. Consider the areas with a high level of stress and compare the results against the relevant material criteria. If the absolute value of the second principal stress of an element is greater than the relevant material criteria then the part will fail.

Note that the plot corresponds to one particular position through the cross-section, as specified by a normalized thickness value where -1 is the bottom of the element, 0 is the centerline through the element, and +1 is the top of the element.

The normalized thickness value can be viewed or modified on the Animation tab of the Plot Properties dialog.

Also consider the first principal stress when the material is brittle.

Things to look for

• Always use the maximum value of stress (either top or bottom result) when checking to see if the part will fail.