阴APP导航

A considerable amount of work has been performed on evaluation of ice-induced fatigue and other mechanical damage and failures in the arctic region. Many of these studies used computer simulations to evaluate the behavior of structures under the severe conditions of Arctic weather. In all such studies it is very important to know the actual stresses created in the structures under the loads and fatigue conditions, so that the created models can be checked against reliable experimental data. The recently developed computerized Complex UltraMARS can be used successfully for creation of such databases.

The application of an ultrasonic non-destructive method for residual stress (RS) measurements has shown that, in many cases, this technique is very efficient and allows measuring the RS both in laboratory conditions and in real structures in field for a wide range of materials. Using this technique, one can measure the RS at the same points many times, studying for instance, the changes of RS under the action of service loading or effectiveness of stress-relieving techniques.

The ultrasonic computerized complex (UCC) for non-destructive measurement of residual and applied stresses that was developed recently includes a measurement unit with transducers and basic supporting software. An advanced database and an Expert System also were developed for analysis of the influence of RS on the fatigue life of welded elements. The developed system allows measuring the RS either averaged through thickness or in surface or subsurface layers. The present version of UCC allows measuring the averaged through thickness biaxial RS in plates 2 - 150 mm thick and surface/subsurface RS at the predetermined depth. The results of ultrasonic RS measurement in large scale welded specimens and structures are also discussed in this paper.