Stress is created in the plastic as it flows through the mold. Friction between the moving plastic and the mold wall causes this stress.
Ideally, the shear stress is less than the critical maximum value for that material. (You can obtain this value from the Material Database).
If a part has a yellow or red Quality Prediction result, find out why. If it is due to high shear stress, make some of the changes recommended here.
If the part is mostly green with some small yellow areas, it can be acceptable. However, carefully examine the other result displays to see exactly how and where the results went wrong.
High shear stress can cause cracks in the plastic, which can make the part degrade and fail.
Try to reduce the friction between the moving plastic and the mold wall. Thicken the part by reducing the plastic viscosity, or by slowing the plastic flow. Some ways of achieving these changes are:
This action reduces the plastic viscosity.
You can make the part thicker at the end of flow or in thin sections.
This action makes the plastic inject more quickly, which increases the shear heating. As the plastic heats up, its viscosity decreases.