| 1. |
- Berglund, Daniel, et al.
(författare)
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Simulation of welding and stress relief heat treatment of an aero engine component
- 2003
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Ingår i: Finite elements in analysis and design (Print). - 0168-874X .- 1872-6925. ; 39:9, s. 865-881
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Tidskriftsartikel (refereegranskat)abstract
- It is important to control key dimensions in aero engine components during manufacture. This is achieved by finding a stable process-parameter window for each manufacturing operation and to choose an order of manufacture which give an adequate result. Production planning has traditionally been carried out from experience and experiments. However, in order to reduce lead-time and cost, computer based numerical simulations using the finite element method is increasingly being used. Simulations can give valuable information about component dimensions, shape, and residual stresses after each manufacturing process. This paper presents a method and the results of a simulation where welding and stress relief heat treatment operations are combined. Computational fluid dynamics was also used to estimate the heat transfer coefficient of the component's surface during the heat treatment.
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| 2. |
- Runnemalm, Henrik, et al.
(författare)
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Virtual manufacturing of light weight aero engine components
- 2009
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Konferensbidrag (refereegranskat)abstract
- Light weight design has been identified as one of Volvo Aero key contribution in the effort to meet the global challenges of reduced CO2 emissions from aviation. This has resulted in a number of design solutions where fabrication of large structural components is the preferable way and has indicated weight savings by up to 20% in comparison to corresponding products in today's existing engines. Introducing these new design solutions requires an existing industrial structure to come up with new and innovative solutions that will support the introduction of the new products. In this paper virtual manufacturing technologies supporting design as well as manufacturing engineers in decision making and preparation of new design solutions will be described.
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| 3. |
- Berglund, Daniel, et al.
(författare)
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Comparison of deformation pattern and residual stresses in finite element models of a TIG-welded stainless steel plate
- 2003
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Ingår i: Trends in welding research. - : ASM International. - 0871707802 ; , s. 826-831
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Konferensbidrag (refereegranskat)abstract
- Information about the shape, dimension and residual stresses in a component after the different manufacturing steps are of great interest in order to reducing cost and time spent during product development. Information about the residual stresses also give input for lifetime prediction, which is important in the aerospace industry. Process parameters and different fixture set-ups can be evaluated without doing a large number of experiments by the use of a virtual model. The finite element method has been used to predict the material response due to welding and the use of this method have shown good correlation between measured and calculated results, especially considering residual stresses. Industrial applications do often involve complex geometrical shapes and thereby make this type of simulations time consuming. Therefore it is of great interest to investigate if simple models can replace detailed analysis at least during the preliminary design stages when a qualitative correct model can give useful result in a short period of time. Comparison between results from 2D, 3D-shell and 3D-solid models are compared in this study and conclusions are drawn about the applicability of the different models.
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| 4. |
- Jansson, E, et al.
(författare)
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On the acoustical function of the violin
- 1997
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Ingår i: 25. Congresso nazionale : Perugia, 21-23 maggio 1997 : atti / Associazione italiana di acustica.
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Konferensbidrag (refereegranskat)
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| 5. |
- Lindgren, Lars-Erik, et al.
(författare)
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Developments in finite element techniques for facilitating the simulation of welding in industrial applications
- 2001
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Ingår i: Mathematical modelling of weld phenomena 5. - London : Institute of Materials. - 1861251157 ; , s. 743-753
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Konferensbidrag (refereegranskat)abstract
- Using the examples of EB welding of a copper canister (for spent nuclear fuel storage) and multirun submerged arc welding of thick steel plates, the finite element (FE) methods (2D and 3D models) developed to simulate such industrial welding applications are examined. With respect to multirun welding, challenges imposed by addition of filler material, history dependency of the material and computer resources are considered. The FE developments discussed include combined shell and solid elements, adaptive meshing, techniques for extending the FE model, and computing phase changes/material properties for low alloy steels.
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| 6. |
- Lindgren, Lars-Erik, et al.
(författare)
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Simulation of multipass welding of a thick plate
- 1999
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Ingår i: International Journal for Numerical Methods in Engineering. - 0029-5981 .- 1097-0207. ; 44:9, s. 1301-1316
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Tidskriftsartikel (refereegranskat)abstract
- Multipass butt welding of a very thick steel plate has been performed. Transient temperatures and residual stresses have been measured. The agreement between calculations and experiments is good. Two different approaches, quiet and inactive elements, for modelling multipass welding are compared. The first approach is straightforward to apply in most finite element codes. The inactive element method requires a code that can regenerate the finite element model automatically or otherwise very tedious manual work is necessary as the elements are added to the model when welds are laid. It is shown that both techniques give the same results but the computational effort is reduced by using inactive elements. It also circumvents the problem in the quiet element approach of choosing properties of elements in the model that represent the case when welds are not laid.
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| 7. |
- Lundbäck, Andreas, et al.
(författare)
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Validation of three-dimensional finite element model for electron beam welding of Inconel 718
- 2005
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Ingår i: Science and technology of welding and joining. - 1362-1718 .- 1743-2936. ; 10:6, s. 717-724
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Tidskriftsartikel (refereegranskat)abstract
- A three-dimensional finite element model for the prediction of the distortion and residual stresses induced during electron beam welding is described. The model is validated by butt welding experiments on two Inconel 718 plates. A particular effort is made to determine a good model for the heat input. A combined conical and double ellipsoid heat source is used to model the deep penetration characteristic of the electron beam and this source is calibrated using the results from a separate thermodynamic simulation, using the ELSIM finite difference code. Parallel computation is used to reduce the overall simulation time in the coupled thermomechanical simulation of welding. The agreement between calculations and experiments is good with respect to the residual stresses. Measured and computed deformations agree qualitatively although they differ in magnitude
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| 8. |
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| 9. |
- Runnemalm, Henrik, et al.
(författare)
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Accuracy in thermal analysis of laser
- 1995
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Ingår i: Computational methods and experimental measurements VII. - Southampton : WIT Press. - 1853123137 ; , s. 85-92
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Konferensbidrag (refereegranskat)abstract
- The paper focuses on the problem of obtaining accurate thermal fields despite the uncertainty of the thermal heat input and thermal properties at high temperatures. The net heat input is the primary factor for obtaining an accurate temperature field. A good correlation between simulations and experiments is obtained. The net heat input during laser welding a bead on a thin plate made of austenitic stainless steel is determined using a water calorimeter. Transient temperature is measured by thermocouples. The FEM is used in the numerical simulation of the process
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| 10. |
- Runnemalm, Henrik
(författare)
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Efficient finite element modelling and simulation of welding
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents development of methods, methodologies and tools for efficient finite element modelling and simulation of welding. A novel 8- to 16-noded solid shell element has been developed. It uses only displacement degrees of freedom, thus it can easily be connected with a regular brick element. The element has proven to perform well in standard tests for shell as well as in geometrical and material non-linear problems. An error based adaptive remeshing scheme has been developed. It is found that the combination of the two error measures, based on the heat flux and the effective stress, is predicting an accurate mesh for a plate and a pipe welding case. To improve the efficiency of material addition in multipass welding two different strategies was compared. These two strategies, named quiet and inactive element, were used in a simulation of a very thick plate. Results showed that the inactive element strategy was preferable in terms of numerical efficiency. A generic process methodology is used to identify and develop critical activities in the modelling and simulation of welding. The methodology is used to compare simulation results of elementary case studies to results of more refined analysis. The elementary case studies is suggested to support decision making in the early design phase of product development.
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