本研究採用有限元素法分析三維螺紋節鋼筋應力集中與二維軸對稱鋼筋應力集中之關係，以二維軸對稱數值分析方法推算三維螺紋節鋼筋應力集中。因三維模型建置過程及分析時間較複雜，在ABAQUS軟體建置模型及分析時間都較二維模型來得複雜及費時，三維模型之數值準確度也較二維模型來得差，因此分析兩者之關係並提出三維模型之轉換式，使得二維軸對稱模型帶入轉換式推衍即可得出三維螺紋節鋼筋之應力集中。並提供各尺寸螺紋節鋼筋應力集中之推衍結果，以及提出分析時出現之各種現象討論，包含直徑及節距對於應力集中影響之分析，與鋼筋竹節表面之根部曲面半徑(r)與竹節節高(h)比值(r/h)對應力集中容差值之分析，以及高應力集中區現象說明。 首先針對三維螺紋節鋼筋分析其應力集中，第二為了判斷螺紋節鋼筋之螺旋角對於應力集中之影響，因而建置三維水平螺紋節鋼筋與之相比，第三建置二維軸對稱鋼筋模型與三維水平螺紋節鋼筋比較，第四找出三者之關係並提出轉換式以及推算結果，最後提出螺紋節鋼筋分析的現象以及討論，以供後續分析螺紋節鋼筋應力集中之參考。 ;The finite element method was used for the stress concentration of the 3D threaded bar reinforcement and the stress concentration of the 2D axisymmetric reinforcement, and the stress concentration of the 3D threaded bar reinforcement was calculated by the 2D axisymmetric numerical analysis method. Because the 3D model building process and analysis time are more complicated, the modeling and analysis time in ABAQUS software is more complicated and time-consuming than the 2D model. The numerical accuracy of the 3D model is also worse than that of the 2D model. Therefore, the analysis of the two, the conversion formula of the 3D model is proposed, so that the 2D axisymmetric model is brought into the conversion formula to calculate the stress concentration of the 3D threaded bar reinforcement. It also provides the calculation results of the stress concentration of the steel bars of various sizes of threaded joints, as well as the discussion of various phenomena that occurred during the analysis. First, analyze the stress concentration of the 3D threaded steel bars. Secondly, in order to determine the influence of the helix angle of the threaded steel bars on the stress concentration, build a 3D horizontal threaded steel bar. Compared with the third, build a 2D axisymmetric steel bar model. Compared with the 3D horizontal threaded steel bar, the fourth finds the relationship between the three and proposes the conversion formula and the calculation result. Finally, the phenomenon and discussion of the threaded steel bar analysis are presented for the reference of the subsequent analysis of the stress concentration of the threaded steel bar.
