Stress Analysis of Bolted Joints Part II. Contact and Slip Analysis of a Four Bolt Joint

Abstract

For up-to-date bolted joints, first of all in vehicles, high strength bolts of 10.9 or even 12.9 are used, which are preloaded up to 90% or even 100% of the yield strength. The primary aim of this high degree utilization is the weight reduction. For the analytic dimensioning of bolted joints, the VDI 2230 Richtlinien German standard [1] provides support. However, the analytic model can mostly consider the true structural characteristics only in a limited way. The analytic modeling is especially uncertain in case of multiple bolted joints when the load distribution among the bolts depends reasonably upon the elastic deformation of the participating elements in the joints over the geometry of the bolted joint. The first part of this paper deals with the problems of numerical modeling and stress analysis, respectively specifying the analytic dimensioning procedure by applying elastic or rather elastic-plastic material law. The error magnitude in bolted joint calculation was examined in case of omitting the existing threaded connectionbetween the bolt and the nutin order to simplify the model. The second part of the paper deals with the dimensioning of stands and cantilevers multi-bolt fixing problems, first of all, with the load distribution among the bolts keeping in view the analysis of the local slipping relations. For demonstrating the above technique, an elaborated numeric procedure is presented for a four-bolted cantilever, having bolted joints pre-tightened to the yield strength.

Share and Cite:

L. Molnár, K. Váradi, J. Holubán and A. Tamási, "Stress Analysis of Bolted Joints Part II. Contact and Slip Analysis of a Four Bolt Joint," Modern Mechanical Engineering, Vol. 4 No. 1, 2014, pp. 46-55. doi: 10.4236/mme.2014.41006.

Conflicts of Interest

The authors declare no conflicts of interest.

 [1] Systematische Berechnung Hochbeanspruchter Schraubenverbindungen Zylindrische Einschrau-Benverbindungen. VDI-Richtlinien, VDI 2230, 2003. [2] L. Molnár, K. Váradi and B. Liktor, “Stress Analysis of Bolted Joints. Part I. Numerical Dimensioning Method,” Modern Mechanical Engineering.