By using an idealised joint model@ the concept of a load/deflection diagram is developed to show the influence of pretensioning through to joint separation. That analysis is then built on to show how the load paths may be determined in a practical joint@ including the effects of prying apart when the load is off-set from the fastener axis@ dimensional tolerances on squareness and flatness of the components@ fastener yielding@ level of pretension@ and changes in materials properties with temperature. Guidance is included on estimating the stiffness contribution made by each component of the joint and@ in particular@ to assist in rapid calculation of the feet@ graphs are provided. Factors governing the selection of fastener size@ avoidance of separation@ and fatigue loading of the fastener are explained. Sketches illustrate the influence of bolt size and material@ hinge point position@ washer and plate and foot thicknesses@ load@ and other parameters on pretension values for bolt yielding and joint separation. Two extensive practical worked examples illustrate the use of the methods. A program of the method@ ESDUpac A8521@ is provided on disc (uncompiled) in the software volume and compiled within ESDUview@ a user-friendly shell running under MS DOS that prompts on screen for input data. The program treats any combination of material properties@ washers of different design on either end of the bolt@ plates between the feet or layered over the feet and under the bolt head or nut@ and non-standard features such as Belleville washers represented by their stiffness.
ESDU 85021 C-2005 history
2012ESDU 85021 C-2012 Analysis of pretensioned bolted joints subject to tensile (separating) forces
2005ESDU 85021 C-2005 Analysis of pretensioned bolted joints subject to tensile (separating) forces.