NLZ

In Figure 16(a), there are properly 7 impulses (e.g., from impulse B1 to impulse B7) in the LZ of wheelset bearing, and there are almost impulses in NLZ of the wheelset bearing due to the small forces applied on defective roller.

There are 7 impulses in the LZ of wheelset bearing (e.g., from impulse B1 to impulse B7); when the defective roller enters the NLZ of wheelset bearing, there are almost significant impulses with a large shock amplitude compared to the LZ.