Study of Manufacturing Process of Holes in Aeroengine Heat Shield

Table 5

Variance analysis table.

Factors	Sum of squares of variance ()	Degrees of freedom ()	-ratio	critical value	Significant
	1800	3	36.73	29.5
	1969	3	40.18	29.5
	49	3	1	29.5
	4593	3	93.73	29.5
	1553	3	31.69	29.5
Error	49	3

Note: is used as the error term. The -ratio in the table is the ratio of the squared sum of the variance of each factor and the error. The critical value of the -ratio greater than is significant. According to the size of the -ratio, the influence degree of each factor on the quality of laser cutting is obtained as follows: . The conclusion of the ANOVA was consistent with the result obtained in Table 4 in the intuitive analysis, which further proves the correctness of the intuitive analysis. It can be seen in Table 5 that , , , and play a leading role in the laser cutting process, and they do not interfere with test error and interaction. The effect of current was not significant compared with the other four parameters; however, it is consistent with current floating with the intuitive analysis.