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1

Determination of Bolt Forces and Normal Contact Pressure Between Elements in the System With Many Bolts for its Assembly Conditions

Grzejda Rafał

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 1

116--121

EN

The paper put forward a thesis that modelling dissymmetric non-linear multi-bolted connections as a system is possible. Modelling of the systems composed of four subsystems on the assembly state was presented. These subsystems included: a couple of joined elements (a flange and a support), a contact layer between them, and bolts. The physical model of the system was described considering the tightening of bolts according to a specific sequence. In this model: the flange and the support were built using spatial finite elements, the contact layer was formed as the non-linear Winkler model, and the bolts were replaced with simplified models made of flexible beams. The calculation model which can be applied to determine the changes in bolt forces, as well as in the normal contact pressure between the joined elements during the tightening of the system and at its end, was presented. The results of sample calculations for the selected multi-bolted system were shown.

2

FE-modelling of a bolted lap connection using a simplified bolt model

Grzejda R.

Modelowanie Inżynierskie

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2017

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T. 31, nr 62

24--28

EN

Modelling and calculations of a bolted lap connection are presented. Analysis of forces acting on the bolts based on the theoretical formulas and using the finite element method (FEM) is performed. In the case of theoretical calculations the recommendations given in the standard PN-EN 1993-1-8 are applied. For a case of numerical calculations a simplified model of the bolt is used. The obtained results of calculations are checked in terms of fulfilment of the adopted criterion for load capacity of the connection. Selected results of simulation studies of the bolted lap connection FEM-model in the form of a displacement map and a reduced stress map of the model under specified external load are pointed out. Based on the comparison of the theoretical and numerical analyses results, usefulness of the simplified bolt model for calculations of operational forces in the bolts in bolted lap connections is determined.

PL

Przedstawiono modelowanie i obliczenia zakładkowego połączenia śrubowego. Przeprowadzono analizę sił występujących w śrubach na podstawie wzorów teoretycznych oraz za pomocą metody elementów skończonych (MES). W obliczeniach teoretycznych zastosowano zalecenia podane w normie PN-EN 1993-1-8. W obliczeniach numerycznych wykorzystano uproszczony model śruby. Otrzymane wyniki sprawdzono pod kątem spełnienia przyjętego kryterium nośności połączenia. Przedstawiono wybrane wyniki badań numerycznych modelu połączenia w postaci mapy przemieszczeń i mapy naprężeń zredukowanych modelu wywołanych zadanym obciążeniem zewnętrznym. Na podstawie porównania wyników obliczeń teoretycznych oraz wyników obliczeń numerycznych określono przydatność uproszczonego modelu śruby do obliczeń sił roboczych w śrubach w połączeniach zakładkowych.

3

Impact of nonlinearity of the contact layer between elements joined in a preloaded bolted flange joint on operational forces in the bolts

Grzejda R.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 3

541--548

EN

Modelling of an asymmetrical preloaded bolted ange joint, loaded with a normal external force is presented. The physical model of the joint is designed as a pair of elements (which are a flexible flange element and a rigid support) clamped using simplified models of bolts. Between the joined elements the Winkler model of a contact layer is introduced. The impact of nonlinearity of the contact layer on operational forces in the bolts is analysed. Conclusions of major importance to modelling of preloaded bolted flange joints are put up.

4

Analysis of the Tightening Process of an Asymmetrical Multi-Bolted Connection

Grzejda R.

Machine Dynamics Research

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2015

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Vol. 39, No. 3

25-32

EN

The paper deals with modelling and calculations of a multi-bolted connection characterized by an asymmetric arrangement of bolts. Equations of system equilibrium on the preloading stage of the connection are described. The iterative algorithm of the computational process is presented, which is related to both nonlinearity of spring elements used for modelling of the contact layer between joined elements and one-sidedness of constraints imposed on the connection. Results of calculations of the selected multi-bolted connection are presented.