Shear rate is the rate of change of shear strain with time.
Shear strain is the ratio of the deformation of the polymer due to a shear force.
Ideally, the shear rate is less than the critical maximum value for that material. (You can obtrain this value fromthe Material Database).
If a part has a yellow or red Quality Prediction result, find out why. If it is due to high shear rate, 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 you can make further improvements.
High shear rate can cause the material to degrade, become brittle, and have a poor surface finish.
To reduce the shear rate in an area, you can increase/decrease the material viscosity, ease the polymer flow through the cavity, and/or apply some of the following recommendations:
Thicken the part
You can make the part thicker at the end of flow or in thin sections.
Decrease the injection time
This action increases the shear heating, which decreases the viscosity.
Increase the melt temperature
This action also decreases the viscosity.
Select a less viscous material (higher melt flow rate).
This action allows a quicker material flow.
Increase the gate size
This action increases the flow rate for a given injection pressure