STRENGTH DESIGN AND LIFE ASSESSMENT OF WELDED STRUCTURES SUBJECTED TOHIGH-TEMPERATURE CREEP

Premature failures of weldments have taken a large percentage among th e failure cases of high temperature components. The accurate predictio n of the high temperature creep behavior of welded components is hence becoming increasingly important in order to realize an optimized desi gn and management of a plant life. In the present paper, design and li fe assessment procedure for welded structures at elevated temperature is discussed. A concept of structural creep-rupture strength is propos ed to define the weldment creep strength reduction factor. Multiaxial effect is taken into account. A damage mechanics approach is introduce d to study the life reduction and ductility reduction due to the prese nce of a weld in structures at high temperature.