МЕЖДУНАРОДНОЕ СОТРУДНИЧЕСТВО
G U A N Q i a o
(P. O. Box 863, Beijing, 100024,China)
DISTORTION-FREE WELDING OF THIN-WALLED
ELEMENTS BASED ON THERMAL TENSIONING
EFFECTS
1
Buckling distortions are more marked than other forms of welding
distortions in manufacturing thin-walled structural elements. They are
the main troublesome problems in sheet metal fabrication where fusion
welding is applied especially for aerospace structures such as sheet
metal formed airframe panels, fuel tanks, shells of jet engine cases
etc. with material thickness less than 4 mm. Extensive research and
development studies to explore distortion-free welding techniques were
carried out at Beijing Aeronautical Manufacturing Technology Research
Institute (BAMTRI).
To prevent buckling, Low Stress No Distortion (LSND) welding
techniques were pioneered at BAMTRI and implemented successfully
for product engineering and component manufacturing. Two innovative
methods of LSND welding techniques have been developed for industrial
application: one is based on the whole cross-section thermal tensioning
effect, the other is based on the localized thermal tensioning effect.
The nature of LSND welding techniques is to create active in-process
control of incompatible (inherent) plastic strains and stresses formation
during welding to achieve distortion-free results implying that no post
weld costly reworking operations for distortion correction is required.
In this paper, the mechanisms of LSND welding techniques either using
whole cross-section thermal tensioning effect or using localized thermal
tensioning effect are described and analyzed in details.
Introduction.
Buckling distortions affect the performance of welded
structures in a great many ways. During the past decades efforts have
been made and progress has been achieved in solving buckling problems
by experts in the welding science and technology field world-wide. Many
effective methods for removal, mitigation and prevention of buckling
distortions adopted before welding, during welding or after welding have
been successfully developed and widely applied in industries (Refs. 1–7).
Over the past 25 years, the present author and his team have devoted
their efforts to achieve distortion-free results in manufacturing thin-
walled aerospace structural components by implementing active in-process
control of inherent residual plastic strain formation during welding without
having to undertake costly reworking operations for distortion correction
after welding (Refs. 8–10). Two innovative methods of LSND welding
1
The paper is published without any redaction.
92 ISSN 0236-3941. Вестник МГТУ им. Н.Э. Баумана. Сер. “Машиностроение”. 2005. № 4
