highly significantP<0.05
Note: P<0.01 (highly significant, **); 0.01≤P<0.05 (significant, *).
Note: P<0.01 (highly significant, **); 0.01≤P<0.05 (significant, *).
When only considered the impact of the drop height on the index, as the drop height increased, the maximum value of the test index had an increasing trend.