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An Empirical Model to Calculate the Threads Stripping of a Bolt Installed in a Tapped Part

Authors: Manuel Martínez Martínez, Daniel Zavala Ríos


To determine the length of engagement threads of a bolt installed in a tapped part in order to avoid the threads stripping remains a very current problem in the design of the thread assemblies. It does not exist a calculation method formalized for the cases where the bolt is screwed directly in a ductile material. In this article, we study the behavior of the threads stripping of a loaded assembly by using a modelling by finite elements and a rupture criterion by damage. This modelling enables us to study the different parameters likely to influence the behavior of this bolted connection. We study in particular, the influence of couple of materials constituting the connection, of the bolt-s diameter and the geometrical characteristics of the tapped part, like the external diameter and the length of engagement threads. We established an experiments design to know the most significant parameters. That enables us to propose a simple expression making possible to calculate the resistance of the threads whatever the metallic materials of the bolt and the tapped part. We carried out stripping tests in order to validate our model. The estimated results are very close to those obtained by the tests.

Keywords: Plasticity, Damage, bolt, stripping, thread assemblies

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[1] Alexander E M, Analysis and Design of Threaded Assemblies, Int. Automotive Eng. Congress and Exposition, Detroit, 1977, Ref. No 770420.
[2] Dose G.F., Pittner K.J, Neuartige Berechnung von Schrauben unter Ber├╝cksichtigung der Werkstoffkennwerte., Konstruktion, 1996, 48.
[3] Thomala, Zur Berechnung der Erforderlichen Mutterhohe Bei Schraubenverbindungen, Konstruktion, 1995, 47.
[4] Martinez-Martinez M, Ferrand A, Guillot J, Finite Element Analysis of Thread Stripping of a Threaded Assembly, Computational Methods in Contact Mechanics V, J. Dominguez and C. A. Brebbia, WITPRESS , 2001, pp. 263-272.
[5] Martinez-Martinez M, Ferrand A, Guillot J, Calculation of Nuts Threads Stripping, Proceedings of 2001 ASME International Mechanical Engineering Congress and Exposition, November 11 to 16, 2001, New York, NY. To be published.
[6] Martinez-Martinez M, Ferrand A, Chaussumier M, Modelling of Thread Stripping in Tapped Parts, Proceedings of 2002 IDMME, May 14 to 16, 2002, Clermont-Ferrand, France.
[7] Chaboche L, 1988, Continuum Damage Mechanics, Parts I and II, J Appl. Mech., 55, pp. 59-72.
[8] ABAQUS/Standar User-s Manual, Volume 1, version 5.8.