Numerical/Experimental Analysis of an API 8-Round Connection

Assanelli, Andrea P.; Xu, Quan; Benedetto, Fabián; Johnson, Daniel; Dvorkin, Eduardo N.

doi:10.1115/1.2794980

Cited by 19 publications

(20 citation statements)

References 9 publications

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“…Assanelli et al 19 used finite element analysis to evaluate the influence of make-up torque in the jump-out load of a a) For the API Buttress connection, the face of the coupling advances to one turn of the base of the triangle stamp for minimum make-up and to the apex of the triangle stamp for maximum make-up. 5 ½ in., J-55 API 8-Round casing connection.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of Standard API Casing Connections and Parametric API Buttress Improvement by Finite Element Analysis

et al. 2016

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Threaded and coupled connections generally present a non-uniform stress distribution, which is related to the higher stiffness of the box when compared to the pin. The non-uniform stress distribution can contribute to fatigue cracks and other failure modes in high pressure oil wells. An API 5CT P110 steel obtained from a seamless pipe was mechanically characterized. FEA models were carried out to investigate and compare two API casing connections under make-up torque and tensile efforts. A parametric study was performed using numerical models to determine the influence of some geometric features on the behavior of the API Buttress threaded connection. The API Buttress connection supported higher tensile loads than the API Short Round, however both standard connections showed high stress concentration in the last engaged thread and a non-uniform stress distribution. The manufacturing of grooves at the first and the last engaged threads proved to be an efficient way to reduce the stress concentration of Buttress casing connection and could be an alternative to the development of new products.

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Section: Resultsmentioning

confidence: 99%

Evaluation of Standard API Casing Connections and Parametric API Buttress Improvement by Finite Element Analysis

et al. 2016

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“…The simulation of threaded connections is characterized by three main non-linearities: surface interactions together with sliding between pin and box, material plasticity and geometric non-linearity due to thread large deformation [9]. Therefore, the problem of thread galling is a complicated system governed by highly non-linear equations for the stress, strain and displacement.…”

Section: Finite Element Modelsmentioning

confidence: 99%

Numerical and experimental distribution of temperature and stress fields in API round threaded connection

Yuan

Yao

Wang

et al. 2006

Engineering Failure Analysis

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“…This shifted value should be used as input for the finite element models since there is a perfect match between the geometry of pin and box in the models. In a previous study of Assanelli et al [4] an analogue shift was observed for an API 8-round threaded connection.…”

Section: A) B)mentioning

confidence: 99%

“…It is general practice to model threaded connections using 2D axisymmetric models, as can be seen in [2] and [4][5][6]. The advantage of this approach is the reduced calculation time compared to full 3D models.…”

Section: General Practicementioning

confidence: 99%

“…It is known from Newport and Glinka [3] that the thread type has an influence on the stress concentration factor in the root of the threads since a thread acts like a notch and has a stress raising effect on the local stress. Assanelli et al [4] showed that the load distribution over the threads can be changed by altering the taper angle of the pin or box, creating a small mismatch.…”

Section: Introductionmentioning

confidence: 99%

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Numerical and experimental study of the fatigue of threaded pipe couplings

Wittenberghe

Baets

Waele

et al. 2009

WIT Transactions on Engineering Sciences

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Threaded pipe couplings are used in the oil and gas industry as an alternative to welding and in applications where pipes should be frequently coupled and uncoupled as is the case for drill pipes. To maintain a sealed and secure connection while being subjected to external variable loads, they are commonly preloaded by using threaded connections with a conical shape. In this study a series of finite element analyses of conical threaded API Line Pipe couplings is carried out to quantify the influence of its contact parameters (coefficient of friction, preload and taper angle). In the assembled pipes, small sliding of the thread contact surfaces is still possible due to elastic deformation under external loads. This means that the contact zones of the threads can change under load, which complicates the analysis of the couplings. It was found that the coefficient of friction between the threads had a significant influence on this sliding. The shape of the threads inherently causes local stress concentrations, which can in turn initiate fatigue cracks. To validate the results of the finite element simulations, both static and dynamic tests were carried out on an API Line Pipe coupling. The preloading of the connection was carried out on a torque machine and an experimental fatigue test was carried out on a four-point bending test setup. Strains measured by strain gauges on the connections are in good agreement with the strains predicted by the finite element simulations. Fatigue cracks appearing emanated from the root of the last engaged thread of the male part of the connection, which is the region with the highest stress concentration factor in the numerical model.

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Numerical/Experimental Analysis of an API 8-Round Connection

Cited by 19 publications

References 9 publications

Evaluation of Standard API Casing Connections and Parametric API Buttress Improvement by Finite Element Analysis

Evaluation of Standard API Casing Connections and Parametric API Buttress Improvement by Finite Element Analysis

Numerical and experimental distribution of temperature and stress fields in API round threaded connection

Numerical and experimental study of the fatigue of threaded pipe couplings

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