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Papers by Jerzy Jachimowicz
Journal of KONES. Powertrain and Transport, 2012
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Journal of KONES. Powertrain and Transport, 2012
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Fatigue of Aircraft Structures, 2012
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Journal of KONES. Powertrain and Transport, 2012
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Fatigue of Aircraft Structures, 2009
Methods for Global and Local FEM Analysis of Riveted Joint on the Example of the PZL M28 Skytruck... more Methods for Global and Local FEM Analysis of Riveted Joint on the Example of the PZL M28 Skytruck Aircraft
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Welding International, 2011
Modelling of the resistance spot welding process on sheet metal by the finite element method was ... more Modelling of the resistance spot welding process on sheet metal by the finite element method was described in the article. The assumptions and theoretical foundations of the modelling of the process, as well as the discussion of the results in terms of applications of the presented modelling method for the determination of the expected joint size, were also demonstrated. The results of the numerical simulation consisting in the alteration of the thermal field during welding were presented in the article.
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![Research paper thumbnail of Applications of ENDOR spectroscopy to radicals of low symmetry: Radical anions of 2-phenylcycl[3.2.2]azines1](https://attachments.academia-assets.com/47679167/thumbnails/1.jpg)
](Journal of Magnetic Resonance (1969), 1975
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This paper deals with the displacement and stress analyses in riveted joint. This is a stage of s... more This paper deals with the displacement and stress analyses in riveted joint. This is a stage of study of the local physical phenomena in riveted joint. The aim of the investigation is to improve the prediction method for the joint failure mode associated with a crack initiation and propagation at a rivet hole. Riveting is the most commonly used method of joining sheet metal components of the aircraft structures. The residual stress and strain state appears in the joint after the riveting process. Furthermore in service condition aircraft structures are subjected to variable fatigue loads. The riveted joints are critical areas of the aircraft structure due to severe stress concentrations, plastic strain and effects such as surface damage (fretting wear) and secondary bending. Therefore the fatigue crack initiation will start at the rivets holes. Fretting fatigue is recognised as a surface damage phenomenon and describes situation where microslip between contacting surfaces appears to give rise to reduction in fatigue life [2]. The object of the analysis is a tensile loaded lap joint. Fatigue tests are performed for the riveted joint specimens consisting of a steel rivet (shank diameter 5mm) and two D-16 aluminium alloy plates (thickness 2.8 mm). Steel and aluminium interaction due to their different properties causes fretting corrosion and decreasing in fatigue life. This feature is convenient to experimental tests. Numerical FE simulations are carried out with the MARC code for a single lap riveted joint specimen. Three-dimensional numerical model is used to analyse the resulting displacement fields at a hole and a rivet in the neighbourhood of a contact interface. Relative displacements between the rivet and the hole are investigated for various friction coefficients. The local numerical model describes a single rivet, a hole and its neighbourhood in two plates. This type of problem requires the use of contact between the elements assembled and non-linear geometric and elasto-plastic multilinear material models to simulate the behaviour of the rivet and plates [1]. The double sided contact for deformable bodies is defined between the two metal plates and between the rivet and the hole. Although the literature on the fatigue behaviour of riveted joints is quite abundant, many aspects are still not sufficiently understood and investigated and, therefore, they require a further study. The advantage of the numerical simulation is to limit development costs and to improve analysis by giving more complete information about contact stress compared to the pure experimental way.
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Procedia Engineering, 2009
The analysis of riveted structures requires a local–global approach in modelling. The local model... more The analysis of riveted structures requires a local–global approach in modelling. The local model is used to calculate the residual stress and strain fields around the rivet hole and analyse the influence of technological imperfections on the quality of the joint. The influence of the rivet with compensator on the stress distribution at the rivet hole is presented. Contact phenomena
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The paper deals with the modelling of riveted joints in aircraft structures with Finite Element M... more The paper deals with the modelling of riveted joints in aircraft structures with Finite Element Method. Presented works were carried out within Eureka project No. E!3496 called IMPERJA. The goal of the IMPERJA project is to increase the fatigue life of riveted joints, which will lead to an increase of the aircraft service life, a smaller number of inspections and lower operation costs of an aircraft. The project assumed FEM modelling of the operating aircraft 's structure at three different complexity levels, namely considering the complete structure, a structural detail and a single riveted joint. The paper presents analyses of various rivet models and calculations of a structure and a riveted joint. In the first part examples of various models, at global and local level, were presented and usefulness of them was discussed, influence of the following simplification was analysed; • neglection of rivets in a model (elements are jointed continuously) • rivet as a rigid element (MPC) • neglection of contact phenomenon • neglection of secondary bending • neglection of residual stresses after riveting process The basis of the analysis was the asymmetric butt joint model with 14 rivets. The model which took into account secondary bending and contact phenomenon was analysed as well. The method of modelling residual stresses with temperature and thermal coefficient was used. In the second part, the example of analysis of riveted joint was demonstrated for a wing of PZL M28 Skytruck aircraft. It 's is a twin-engine, high-wing, cantilever monoplane of all-metal structure with maximum take-off and landing weight 7500 kg. A submodeling technique was used there. At first, part of the wing model, based on a CAD model, was built. It includes 7 ribs and 6 bulkheads between them. Dimensions of the model eliminate stress perturbation, connected with boundary conditions, in the area near the middle rib. It was a shell model. The boundary conditions were taken on a basis of operation data. Presence of rivets wasn't taken into account. Instead of this, parts were connected continuously (nodes were merged). The Linear model of material was used. The purpose of the part of the wing model was to gain accurate boundary conditions for next model of riveted joint on the middle rib. The behaviour of whole model is correct but stress distribution around rivets is not correct. A shell model of riveted joint was build. A boundary conditions were set on a basis of result from previous analysis. Forces, instead of displacements, were used, as boundary conditions, on account of a large stiffness difference between part models (part of wing and riveted joint model). The nonlinear model of material was used. A contact effect and secondary bending were taken into account. Thanks to that, phenomena around rivets were represented considerably better. Results from this analysis could be used as boundary conditions in a detailed calculation of one or few rivets with solid elements. Such a model was considered as well. The presented method allows to analyse phenomena that appear around a rivet in a real structure, during operation. Analyses were performed with MSC PATRAN, NASTRAN and MARC software.
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Journal of KONES. Powertrain and Transport, 2012
Bookmarks Related papers MentionsView impact
Journal of KONES. Powertrain and Transport, 2012
Bookmarks Related papers MentionsView impact
Fatigue of Aircraft Structures, 2012
Bookmarks Related papers MentionsView impact
Journal of KONES. Powertrain and Transport, 2012
Bookmarks Related papers MentionsView impact
Fatigue of Aircraft Structures, 2009
Methods for Global and Local FEM Analysis of Riveted Joint on the Example of the PZL M28 Skytruck... more Methods for Global and Local FEM Analysis of Riveted Joint on the Example of the PZL M28 Skytruck Aircraft
Bookmarks Related papers MentionsView impact
Welding International, 2011
Modelling of the resistance spot welding process on sheet metal by the finite element method was ... more Modelling of the resistance spot welding process on sheet metal by the finite element method was described in the article. The assumptions and theoretical foundations of the modelling of the process, as well as the discussion of the results in terms of applications of the presented modelling method for the determination of the expected joint size, were also demonstrated. The results of the numerical simulation consisting in the alteration of the thermal field during welding were presented in the article.
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Journal of Magnetic Resonance (1969), 1975
Bookmarks Related papers MentionsView impact
This paper deals with the displacement and stress analyses in riveted joint. This is a stage of s... more This paper deals with the displacement and stress analyses in riveted joint. This is a stage of study of the local physical phenomena in riveted joint. The aim of the investigation is to improve the prediction method for the joint failure mode associated with a crack initiation and propagation at a rivet hole. Riveting is the most commonly used method of joining sheet metal components of the aircraft structures. The residual stress and strain state appears in the joint after the riveting process. Furthermore in service condition aircraft structures are subjected to variable fatigue loads. The riveted joints are critical areas of the aircraft structure due to severe stress concentrations, plastic strain and effects such as surface damage (fretting wear) and secondary bending. Therefore the fatigue crack initiation will start at the rivets holes. Fretting fatigue is recognised as a surface damage phenomenon and describes situation where microslip between contacting surfaces appears to give rise to reduction in fatigue life [2]. The object of the analysis is a tensile loaded lap joint. Fatigue tests are performed for the riveted joint specimens consisting of a steel rivet (shank diameter 5mm) and two D-16 aluminium alloy plates (thickness 2.8 mm). Steel and aluminium interaction due to their different properties causes fretting corrosion and decreasing in fatigue life. This feature is convenient to experimental tests. Numerical FE simulations are carried out with the MARC code for a single lap riveted joint specimen. Three-dimensional numerical model is used to analyse the resulting displacement fields at a hole and a rivet in the neighbourhood of a contact interface. Relative displacements between the rivet and the hole are investigated for various friction coefficients. The local numerical model describes a single rivet, a hole and its neighbourhood in two plates. This type of problem requires the use of contact between the elements assembled and non-linear geometric and elasto-plastic multilinear material models to simulate the behaviour of the rivet and plates [1]. The double sided contact for deformable bodies is defined between the two metal plates and between the rivet and the hole. Although the literature on the fatigue behaviour of riveted joints is quite abundant, many aspects are still not sufficiently understood and investigated and, therefore, they require a further study. The advantage of the numerical simulation is to limit development costs and to improve analysis by giving more complete information about contact stress compared to the pure experimental way.
Bookmarks Related papers MentionsView impact
Procedia Engineering, 2009
The analysis of riveted structures requires a local–global approach in modelling. The local model... more The analysis of riveted structures requires a local–global approach in modelling. The local model is used to calculate the residual stress and strain fields around the rivet hole and analyse the influence of technological imperfections on the quality of the joint. The influence of the rivet with compensator on the stress distribution at the rivet hole is presented. Contact phenomena
Bookmarks Related papers MentionsView impact
The paper deals with the modelling of riveted joints in aircraft structures with Finite Element M... more The paper deals with the modelling of riveted joints in aircraft structures with Finite Element Method. Presented works were carried out within Eureka project No. E!3496 called IMPERJA. The goal of the IMPERJA project is to increase the fatigue life of riveted joints, which will lead to an increase of the aircraft service life, a smaller number of inspections and lower operation costs of an aircraft. The project assumed FEM modelling of the operating aircraft 's structure at three different complexity levels, namely considering the complete structure, a structural detail and a single riveted joint. The paper presents analyses of various rivet models and calculations of a structure and a riveted joint. In the first part examples of various models, at global and local level, were presented and usefulness of them was discussed, influence of the following simplification was analysed; • neglection of rivets in a model (elements are jointed continuously) • rivet as a rigid element (MPC) • neglection of contact phenomenon • neglection of secondary bending • neglection of residual stresses after riveting process The basis of the analysis was the asymmetric butt joint model with 14 rivets. The model which took into account secondary bending and contact phenomenon was analysed as well. The method of modelling residual stresses with temperature and thermal coefficient was used. In the second part, the example of analysis of riveted joint was demonstrated for a wing of PZL M28 Skytruck aircraft. It 's is a twin-engine, high-wing, cantilever monoplane of all-metal structure with maximum take-off and landing weight 7500 kg. A submodeling technique was used there. At first, part of the wing model, based on a CAD model, was built. It includes 7 ribs and 6 bulkheads between them. Dimensions of the model eliminate stress perturbation, connected with boundary conditions, in the area near the middle rib. It was a shell model. The boundary conditions were taken on a basis of operation data. Presence of rivets wasn't taken into account. Instead of this, parts were connected continuously (nodes were merged). The Linear model of material was used. The purpose of the part of the wing model was to gain accurate boundary conditions for next model of riveted joint on the middle rib. The behaviour of whole model is correct but stress distribution around rivets is not correct. A shell model of riveted joint was build. A boundary conditions were set on a basis of result from previous analysis. Forces, instead of displacements, were used, as boundary conditions, on account of a large stiffness difference between part models (part of wing and riveted joint model). The nonlinear model of material was used. A contact effect and secondary bending were taken into account. Thanks to that, phenomena around rivets were represented considerably better. Results from this analysis could be used as boundary conditions in a detailed calculation of one or few rivets with solid elements. Such a model was considered as well. The presented method allows to analyse phenomena that appear around a rivet in a real structure, during operation. Analyses were performed with MSC PATRAN, NASTRAN and MARC software.
Bookmarks Related papers MentionsView impact