| 1. |
- Fällström, Karl-Evert, et al.
(författare)
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A nondestructive method to determine material properties in anisotropic plates
- 1991
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Ingår i: Polymer Composites. - : Wiley. - 0272-8397 .- 1548-0569. ; 12:5, s. 293-305
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Tidskriftsartikel (refereegranskat)abstract
- Material parameters in anisotropic rectangular plates are determined in a nondestructive way. Real-time, TV-holography is used to determine frequencies and shapes of the first five modes of vibration of plates with free-free boundary conditions. According to rules given in the paper, finite element analysis is then used to determine two effective Young's moduli, the shear modulus, and the Poisson's ratio
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| 2. |
- Jonsson, Erland, 1946, et al.
(författare)
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A practical dependability measure for degradable computer systems with non-exponential degradation
- 1994
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Ingår i: IFAC Symposium on Fault Detection, Supervision and Safety for Technical Processe - SAFEPROCESS 1994. ; Vol. 1, s. 231-237
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a vectorized measure for a set of behavioural dependability attributes. The measure is based on Markov processes and is intended for practical dependability trade-offs. It describes the system performance on a number of service levels. Thus, it is possible to merge attributes such as reliability, safety and performability into one single quality. Whereas reliability describes the functional fulfillment of a system, performability reflects its ability of functional degradation. The safety attribute handles a class of failures with catastrophic consequences and can be accommodated by means of introducing two or more service levels for a failed system.Many systems exhibit time-dependent degradation rates and non–exponential lifetimes. This situation can be handled by means of applying phase–type assumptions and introducing some additional states to the system, which would allow us to remain within the universe of Markov modelling.
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| 3. |
- Jonsson, Mikael, et al.
(författare)
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Experimentally determined deformations and stresses in narrow gap and single-U multi-pass butt-welded pipes
- 1991
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Ingår i: Proceedings of the 10th International Conference on Offshore Mechanics and Arctic Engineering, 1991. - New York : American Society of Mechanical Engineers. - 0791807193 ; , s. 17-24
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Konferensbidrag (refereegranskat)abstract
- Multi-pass butt-welding of thick walled pipes is studied. Two different groove shapes are used, single-U and narrow gap groove. Strains have been measured on both the pipe outer and inner surfaces during and after welding. Residual stresses and radial deflections have been measured on the outer surface after welding. The measured quantities are compared and discussed for the two different groove shapes. Residual stresses at the weld center and radial deflections were somewhat larger for the narrow gap groove. Furthermore, the residual stress fields for both grooves were found to be rotationally nonsymmetric. The experimentally obtained residual stresses and radial deflections are compared with corresponding analytical and empirical results based on methods from the literature and with numerical results for the same pipe from a separate study. Deviations between the measurements (on OX524D) and the results from the literature are discussed.
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| 4. |
- Jonsson, Mikael, et al.
(författare)
-
Experimentally determined deformations and stresses in narrow-gap and single-U multi-pass butt-welded pipes
- 1993
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Ingår i: Journal of Offshore Mechanics and Arctic Engineering-Transactions of The Asme. - : ASME International. - 0892-7219 .- 1528-896X. ; 115:2, s. 116-122
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a study of the multi-pass butt-welding of thick-walled pipes. Two different groove shapes were used: single-U and narrow-gap grooves. Strains were measured on both the pipe outer and inner surfaces during and after welding. Residual stresses and radial deflections were measured on the outer surface after welding. Measured parameters of the two different groove shapes are compared and discussed. Residual stresses at the weld center and radial deflections in the narrow-gap pipe were somewhat larger than those in the single-U pipe. The residual stress fields of both types of groove were found to be rotationally nonsymmetrical. The experimentally obtained residual stresses and radial deflections are compared with corresponding analytical and empirical results based on methods described in the literature and with numerical results for the same pipe from a separate study. Deviations between the measurements presented in this study and published results are discussed.
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| 5. |
- Jonsson, Mikael
(författare)
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Simulation of dynamical behaviour of a front wheel suspension
- 1991
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 0042-3114 .- 1744-5159. ; 20:5, s. 269-281
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Tidskriftsartikel (refereegranskat)abstract
- A MacPherson front wheel suspension and its components are modelled with the finite element method. Nonlinearities due to both the geometry and the characteristics of the components (springs, dampers and bushings) are considered. The force due to a given compression/elongation of the spring strut is calculated and compared with experimental results. Kinematical results, change in track width and camber angle, are also shown and compared with experimental results. Good agreement between numerical and experimental results is obtained.
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| 6. |
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| 7. |
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| 8. |
- Lindgren, Lars-Erik, et al.
(författare)
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Accuracy and efficiency in computational plasticity
- 1991
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Ingår i: Proceedings of the International Conference on Mechanics of Solids and Structures. - Singapore : World Scientific and Engineering Academy and Society. - 9810207387
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Konferensbidrag (refereegranskat)
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| 9. |
- Lindgren, Lars-Erik, et al.
(författare)
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Computational model of flame-cutting
- 1993
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Ingår i: Journal of engineering materials and technology. - : ASME International. - 0094-4289 .- 1528-8889. ; 115:4, s. 440-445
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Tidskriftsartikel (refereegranskat)abstract
- A computational model for simulation of flame-cutting has been developed. Two different cutting conditions are compared with respect to the residual stresses. The first case is a plate cut at room temperature and the other is the cutting of a preheated plate. The model depends on measured micro-structure to estimate the required heat input. The model is verified by comparing the calculations for the preheated plate with experimentally obtained residual stresses. Lower residual stresses in the preheated plate prevents subsequent cracking
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| 10. |
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