Predikce distorzí tlustostěnných svařovaných konstrukcí

Distortion prediction of heavy-wall welded constructions

journal article - other

Czech

This article is engaged in computational modelling of welding heavy-wall constructions and resulting prediction of residual distortions. It is necessary to determine resulting distortions very often at the cases of geometrically and topology complex heavy-wall welded constructions as e.g. hulls of deepwatermans or components of fusion reactor. The aim of works is optimization technology of welding with regard to minimization of residual distortions. Numerical simulations of welding with the aid of FEM are very efficient instrument for prediction of distortions. We can use for these purposes e.g. commercially accessible product Sysweld. Base of success is correct attunement of characteristics, which define the model of heat source. To this purpose series of verification experimental measurements have been accomplished on the simple solids (plates). Primary simulations used of classically heat source moving in time, which is very exacting in term of computational time. On this account it is difficult to apply of above-mentioned heat source for simulation of welding real heavy-wall steel constructions with many weld joints. That is why the other possibilities have been searched for entering heat source. Perspective possibility is setting of total inserted heat into the model of weld bead in a very short time. This method is called macro bead deposit (MBD). Particular possibilities of MBD are setting of temperature into the nodes or setting heat into the elements. In many cases we need to weld large construction units. However utilization of numerical simulations is limited with time demandingness, which passes from hardware equipment. On this account a new method of welding simulation based on so-called local and global approach has been created. Methodology of local and global approach is based on transferring of local weld joints partial effects onto the global model, which represents the whole heavy-wall welded construction. Selected part of fusion reactor vacuum vessel segment was manufactured as a real model on scale 1:1. This mock-up is an example of extremely complex welded heavy-wall construction. In this case local and global approach has been successfully used.

This article is engaged in computational modelling of welding heavy-wall constructions and resulting prediction of residual distortions. It is necessary to determine resulting distortions very often at the cases of geometrically and topology complex heavy-wall welded constructions as e.g. hulls of deepwatermans or components of fusion reactor. The aim of works is optimization technology of welding with regard to minimization of residual distortions. Numerical simulations of welding with the aid of FEM are very efficient instrument for prediction of distortions. We can use for these purposes e.g. commercially accessible product Sysweld. Base of success is correct attunement of characteristics, which define the model of heat source. To this purpose series of verification experimental measurements have been accomplished on the simple solids (plates). Primary simulations used of classically heat source moving in time, which is very exacting in term of computational time. On this account it is difficult to apply of above-mentioned heat source for simulation of welding real heavy-wall steel constructions with many weld joints. That is why the other possibilities have been searched for entering heat source. Perspective possibility is setting of total inserted heat into the model of weld bead in a very short time. This method is called macro bead deposit (MBD). Particular possibilities of MBD are setting of temperature into the nodes or setting heat into the elements. In many cases we need to weld large construction units. However utilization of numerical simulations is limited with time demandingness, which passes from hardware equipment. On this account a new method of welding simulation based on so-called local and global approach has been created. Methodology of local and global approach is based on transferring of local weld joints partial effects onto the global model, which represents the whole heavy-wall welded construction. Selected part of fusion reactor vacuum vessel segment was manufactured as a real model on scale 1:1. This mock-up is an example of extremely complex welded heavy-wall construction. In this case local and global approach has been successfully used.

svařování, MKP, distorze, ITER

welding, FEM, distortion, ITER

JARÝ, M.; DIVIŠ, V.; VLČEK, L.

2009

9. 11. 2009

AF Power agency a.s.

Praha

1802-8535

All for Power

3

4/2009

Czech Republic

110

114

5