Overview
ABSTRACT
The aim of this article is to explain the behavior of axially loaded screw joints. A prestressed joint subjected to an external stress carried by the bolt axis is provided: prestressing, loading the joint and joining. Following, the determination of stiffness is presented, such as the distribution of constraints, the axial stiffness of the bolt or the stiffness of the assembled parts. Thermal stresses are then addressed: general expression, specific case, calculation of constraints, and so forth. The article concludes with discussions concerning the distance between two successive bolts or screws.
Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.
Read the articleAUTHOR
-
Jean GUILLOT: Professor Emeritus - National Institute of Applied Sciences of Toulouse (INSAT)
INTRODUCTION
The first part of this report deals with the behavior of preloaded bolted assemblies for which it can be assumed that the load applied to them is axial.
For this type of assembly, the additional stress borne by the bolt is always much lower than the applied stress and depends on the relative stiffness of the assembly components and the shape of the parts.
This phenomenon, which is characteristic of prestressed systems, is particularly interesting in the case of fatigue stresses, since, if sufficient prestressing has been installed, a judicious choice of the shape of the parts and their stiffness can greatly reduce the value of the alternating stress in the screw and thus ensure good fatigue safety.
In the second part, the latest models for calculating the stiffness of bolts and parts are presented and discussed. The calculation of stresses due to temperature variations is then addressed, as well as the problems of contact pressure distribution at the interface and the determination of the spacing between two successive bolts.
The Ultimate Scientific and Technical Reference
This article is included in
Mechanical functions and components
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Calculation of bolted assemblies
Preloaded assembly subjected to an external force carried by the bolt axis
Bibliography
The Ultimate Scientific and Technical Reference
