scope:

This standard, analogously to VDI 2230 Part 1, applies to high-strength bolted joints made of steel with screw thread, in other words, to strength grades 8.8 to 12.9 or 70 and 80 and with a frictional transmission of the working load which basically acts  on the clamped components or on the structure. As regards bolts made of other materials, or with lower strength grades or with strengths which deviate from DIN ISO 898-1, the standard can be applied mutatis mutandis.

This standard does not in principle do away with the need for experimental tests or where applicable, when analytical methods are used, for numerical analyses to verify the results of calculations. This is in particular advisable in the case of critical MBJs and also with analytical approaches which examine the system with a marked degree of simplification (such as, for example, the rigid body model).

The principle aim of the standard is to provide design engineers with assistance in determining and separating out the most highly loaded SBJ within a bolt array (MBJ). This is done by describing different calculation methods and also by their systematic presentation with respect to procedure and to possibilities and limits. With the loading and calculation quantities thus obtained by calculation an improvement is achieved in the quality of the subsequent functionally and operationally safe design as specified in VDI 2230 Part 1.

With approximative analytical calculations, methods of rigid body mechanics will, with comparatively little effort, yield results which can be precise enough for a series of practical cases. However it is not possible to provide criteria of universal application for this. Ultimately it is the responsibility of the design engineer to verify his results. While paying due regard to practical experience, corrections have been made in some cases to give a closer approximation to real situations.

In cases requiring a more precise calculation and where FE results are not available, the analytic methods of elastomechanics are a possibility. However these are more complex and are not suitable for use with all calculation problems.

The aim of the software-independent information regarding FE application is firstly to provide the engineer with useful modelling variants depending on the objective of the FE calculation. In order to reduce the number of variants, different classes of model have been defined which make it possible to develop a realistic computational model which nevertheless does not involve an unacceptable level of effort.

Secondly, the closeness of the results to reality should be ensured by requirements relating to evaluation  of the FE results for the most highly loaded bolt and relating to determination of the loading and calculation quantities required for calculations in accordance with VDI 2230 Part 1. In this way VDI 2230 Part 1 and Part 2 supplement each other.