FE Analysis of Stress Distribution in Inner Upset Transitional Section of Drill Pipe

Analyzed and calculated here in the paper are the finite elements of the stress distribution and concentration factors of the inner upset transitional section of the G-105 Φ127 mm×9.17 mm IEU drill pipe under tensile and bending loads. The result shows the key data of the said drill pipe, namely, MIU=103.7~161.9mm, and R>300mm; stress concentration factor K_t=1.011~1.06 under tensile stress and stress concentration factor K_tb<1 under bending stress.