length of tangent

On the basis of analysing their advantages and drawbacks,a calculation algorithm of fixed-length tangent based on layered thickness is proposed,which overcomes some deficiencies of the above-mentioned two typical approaches.

在分析顶尖高度法和相邻截面面积变化率法两种典型的层片厚度计算方法原理的基础上,根据光滑曲线可由其上切线包络的原理,提出了一种基于定长切线的层片厚度计算方法,解决了顶尖高度法层厚计算公式太多,曲率半径ρ计算较困难,而相邻截面面积变化率法计算截面面积精度要求高,且难以找到最佳层厚的问题。