SHAKEDOWN OF BOLTS WITH A ONE-SIDED PROPAGATING CRACK

Mindaugas Leonavičius,Marijonas Sušukšta

doi:10.1080/13923730.2002.10531260

Mindaugas Leonavičius, Marijonas Sušukšta

Open Access

https://doi.org/10.1080/13923730.2002.10531260

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Abstract

Abstract Cyclic strains of joints may cause formation of a crack or cracks in a bolt thus changing its loading conditions. After crack appearance in a bolt it can be used if its length does not exceed a critical one. Modification of the shakedown theorem—the method of additional load—was applied in the investigation. The results—the analytical expressions of shakedown conditions are in a sufficiently good agreement with those achieved by other methods. Differences occur due to failure to get an accurate analytic expression. Solution of the shakedown problem plays an essential role in determining the safety factor of bolts subjected to cyclic strains.

Highlights

IntroductionConditions that are sufficient for the development of shakedown are validated by the Melan's principle (the static theorem of shakedown) and Coiter's kinematic theorem
Conditions that are sufficient for the development of shakedown are validated by the Melan's principle and Coiter's kinematic theorem
The results - the analytical expressions of shakedown conditions are in a sufficiently good agreement with those achieved by other methods

Summary

Introduction

Conditions that are sufficient for the development of shakedown are validated by the Melan's principle (the static theorem of shakedown) and Coiter's kinematic theorem. The further investigations of shakedown theories are presented in works of G. Provided defect (crack) is propagating, the rupture risk and evolution of shakedown conditions have to be investigated. The analytical expressions [9,10,11,12] derived and shakedown diagrams developed on their basis are used to elaborate a reserve calculation procedure for a progressive profile change in different threaded joints (without a crack, with one- and double-sided cracks). The shakedown of a bolt with a double-sided crack has been previously investigated [I 0, 12]. Modification of the static theorem of shakedown - the method of additional load- was applied in the investigation [10]. In the present work this method is used for a bolt subjected to a complex deformation when a one-sided fatigue crack propagates over the cross-section of the bolt

The investigation aim

Geometrical properties of the cross-section

Conditions of shakedown

Conclusions