加之，审美是容易产生疲劳的。
情绪较好的时候，精神疲劳不明显，而情绪低落时，则精神容易产生疲劳。
When good mood, mental fatigue is not obvious, and depressed, then the spirit prone to fatigue.
并且它形状复杂、刚性差，又存在严重的应力集中现象，容易产生疲劳破坏。
The shape is very complex, rigidity is poor. It exist serious stress concentrates, and it can cause fatigue break down easily.
应用推荐