The calculated results and the measurement results of X-rays are consistent, which further improves the simulation accuracy of the welding stress
The applied stresses on the rod tip can be classified into stresses by the designed bottom spring, by the upward flowing coolant, by the capsule vibration, and by the residual welding stress
However, the study of the welding temperature field is a prerequisite for the analysis of welding stress
and deformation .
The welding strength is given effects in terms of different parameters: protruded length, surface roughness, welding time, welding stress
, and the ultrasonic parameters which have been preset.
After introducing types of welding residual stress and distortion, topics discussed include using computational welding mechanics to understand welding stress
; modeling the effects of phase transformations on welding distortion; and minimizing welding distortion using such methods as differential heating, thermal tensioning methods, weld cooling, hybrid arc laser welding, and reverse side heating.
The experimental welding stress
is set at a low level of 0.2 MPa.
He covers the temperature field in welding, welding stresses
and strains, the load-carrying capacity of welded structures, diagnostics and prediction of the residual life of welded structures, acoustic emission techniques for the analysis of welded structures, and numerical technical and tests for welded structures.
As a result of a welding process residual welding stresses
are close to or even exceeding a material yield point.
In the case of designing ship's structure by welding technology on materials made of applied alloy, maximum stress of parts in contact with the sea water should not exceed 0,4 [R.sub.0,2] Due to high ratio between the values of residual welding stresses
and allowed stresses ([[sigma].sub.1,2]/[R.sub.0.2]) approximately 0,6 in weld and 0,5 in the basic material, it is necessary to make their relaxation in the ship structure which is in contact with the sea water.
The use of ultrasonics to impart compressive stresses into metallic parts was originally invented in Russia to reduce welding stresses
and deformations, introduce compressive stresses, increase corrosion-fatigue strength of welded joints, and enhance fatigue resistance at subzero temperatures.
With the higher welding stresses
produced by the unnecessary repair, in time a failure would then develop in equipment that would not have occurred if the repair had not been undertaken.
In order to avoid welding stresses
underannealing should be applied at temperatures ranging from 723 K to 773 K using the soaking time of 0.54hours.