Fatigue analysis of aluminum drill pipes

Abstract

An experimental program was performed to investigate the fundamental fatigue mechanisms of aluminum drill pipes. Initially, the fatigue properties were determined through small-scale tests performed in an optic-mechanical fatigue apparatus. Additionally, full-scale fatigue tests were carried out with three aluminum drill pipe specimens under combined loading of cyclic bending and constant axial tension. Finally, a finite element model was developed to simulate the stress field along the aluminum drill pipe during the fatigue tests and to estimate the stress concentration factors inside the tool joints. By this way, it was possible to estimate the stress values in regions not monitored during the fatigue tests

Finite element analysis of tooth load distribution on P-110S conic threaded connections

“…Brennan and Dover [11] made analysis in stress strength on both pipe threaded and conic threaded connections. Placido [12] conducted some experiments on full and reduced scale samples of aluminum drill pipes under cyclic bending and constant tensile loads to investigate their fatigue mechanism. Tanaka [13,14] introduced a modified two-dimensional finite element method to analyze such cases as threaded connections subjected to a transverse displacement and flange coupling under an arbitrary type of loading for typical examples of the threaded connections subjected to an external load.…”

Estimation of the drill pipes residual resource under the multiaxial stress state

“…where N -the number of cycles to failure; σ -the effective stress in the dangerous section of the experimental sample. For example, the authors of [1,2] perform tests of the fatigue of aluminum and steel drill pipes under the action of alternating normal stresses. In addition, a qualitative analysis of the results is carried out, but the explicit form of dependence (1) is not provided.…”

Inverse solution to heat transfer coefficient during heat assembly of aluminum alloy drill pipes

“…MI Lourenco et al introduced experimental testing procedures targeting different pipe materials (Al-Zn-Mg alloys) and sizes, and performed numerical analysis. 2,3 During assembly, steel joint is heated and then screwed to the end of aluminum alloy pipe; after cooling, the assembly can provide reliable permanent connection. Vadim Tikhonov et al studied in detail the stress distribution within the assembly and calculated the stress concentration factors under different axial loads, flexural moment ranges, interference friction coefficients, and interference magnitudes of connection.…”