A parametric study of residual stresses in multi-pass butt-welded stainless steel pipes

Simulation of welding has advanced from the analysis of laboratory setups to real engineering applications during the last three decades. This development is outlined and the directions for future research are summarized in this review, which consists of three parts. This part shows that the increased complexity of the models gives a better description of the engineering applications. The important development of material modeling and computational efficiency are outlined in Parts 2 and 3, respectively.

Finite element modeling and simulation of welding part 1: increased complexity

Simulation of welding has advanced from the analysis of laboratory setups to real engineering applications during the last three decades. This development is outlined and the directions for future research are summarized in this review, which consists of three parts. The material modeling is maybe the most crucial and difficult aspect of modeling welding processes. The material behavior may be very complex for the large temperature range considered.

Finite element modeling and simulation of welding. part 2: improved material modeling

Welding simulation has advanced from the analysis of laboratory setups to real engineering applications during the last three decades. This development is outlined and the directions for future research are summarized in this review, which consists of three parts. This parts focuses on computational strategies and how they are integrated with other methods to facilitate the use of simulations in engineering. These developments have lead to the increased application of welding simulations in industry.

Finite element modeling and simulation of welding. part 3: efficiency and integration

http://astakhov.tripod.com/MC/FEA1976-1996.pdf

Finite-element analysis and simulation of machining: a bibliography (1976–1996)

Single pass butt-welding of a pipe is studied. Low heat input has been used to obtain high cooling rate with adherent martensite in the final phase transformation in the heat affected zone. Strains and stresses have been measured during and after welding on the pipe outer surface. Deviations from rotationally symmetric strain and stress fields in the pipe are studied. Two different analytical solutions for the residual stress field from the literature are discussed. The experimentally obtained residual stresses are compared with those analytical solutions. Qualitatively good agreement between experiments and analytical solutions was obtained, although the analytical solutions do not consider effects of phase transformations.

Experimentally determined transient and residual stresses in a butt-welded pipe

Deformations and stresses during butt-welding of a pipe are calculated as well as the residual deformations and stresses. The temperature field during welding is calculated using an analytical solu ...

Residual stresses and deformations in a welded thin-walled pipe

The expression “acoustic optimization” can be applied to numerous different disciplines within the field of acoustics. From seismic waves, sound in the atmosphere through bioacoustic, psychoacoustics, and room and theater acoustics over shock and vibration in mechanical structures. This paper deals with the latter. Sound generated by vibrating structures is often called noise which is to be minimized. However, not all vibrating structures produce noise, for example the violin is also a vibrating structure that in most people's opinion produces sound called music. In the case of the violin, great effort is made not to minimize but to optimize the sound, i.e. to get the “right” sound out of the structure. Acoustic optimization within this discipline involves automatic changes of structural design variables to obtain minimum or specified sound in specified regions inside or outside the structure. Examples of problem formulations and some theoretical considerations in the field of acoustic optimization in connection with vibrating mechanical structures will be pointed out. Four simple test cases are included as numerical examples of the method proposed.

Optimization of acoustic response

Simulation of automatic butt-welding of large plates was investigated. Two different steels were considered. The plates were tack-welded before the butt-welding. The simulation includes the tack-welding, the butt-welding and the cooling to room temperature. The simulations should lead to an understanding of the mechanics behind the change in gap width in front of the moving arc, which is of importance in automatic welding production. The residual stresses due to the butt-welding were also studied. The magnitude and the distribution of the residual stresses are important in design of welded structures. The change in gap width in front of the moving arc and the residual stresses depend on the material in the plates, the restraints of the plates, the size of the plates and the welding parameters. The most important welding parameters are the arc energy per unit length of the weld and the welding speed. The change in gap width depends also on the tack-welding procedure.

Deformations and Stresses in Butt-Welding of Large Plates With Special Reference to the Mechanical Material Properties

In butt joint welding of plates, the change in root opening in front of the welding arc is of great importance. In order to automate the welding process, one must know how the change in root opening is affected by welding variables and plate configuration. The most important welding variables are the welding speed and the arc energy per unit length of the weld. The configuration is dependent on the material of the plates, their size, their restraints and the tack welding procedure. In this paper, the influence of the tack welding procedure on the change in root opening was inves­ tigated. This change during the first part of welding depends on the order in which the tack welds are made. It is also affected by the starting position of the welding arc. These effects were studied in seven theoretical analyses —three cases where the tack welding procedures differed and four cases where the tem­ perature fields at the beginning of the butt joint welding differed. In two of the cases, theoretical results were compared with experiments. In the theoretical anal­ yses, the finite element method was used. It was found that the change in root opening during the first part of welding is strongly dependent on the tack welding procedure.

Mikael Jonsson

Papers

Experimentally determined transient and residual stresses in a butt-welded pipe

Residual stresses and deformations in a welded thin-walled pipe

Optimization of acoustic response

Deformations and Stresses in Butt-Welding of Large Plates With Special Reference to the Mechanical Material Properties

Simulation of Tack Welding Procedures in Butt Joint Welding of Plates