Review of Concepts and Status of Procedures for Fracture-Safe Design of Complex Welded Structures Involving Metals of Low to Ultrahigh Strength Levels

Rapid Inexpensive Tests for Determining Fracture Toughness

“…The DWT cannot be used for the nonferrous metals such as aluminum or titanium alloy s since they do not display sharp transitions in fracture toughness with temperature . This lack of a sharp transition in these materials is a result of only a ductile (microvoid coalescence) microfracturing mode operating for fracture generated by impact loading over a wide range of temperature (-320 to +300° F) (Goode and Huber , 196 5;Pellini , 1965 Figure G-9 , the calculated K i~ values are in good agreement with measurements.…”

“…The rise of the DT energy curve with temperature is relatable to the nilductility transition temperature (NDT) and to the Robertson crack arrest temperatu re (CAT) curve for low-and intermediate-strength steels (Pellini et al, 1965;Pellini and Loss, 1969;Hawthorne and Loss, 1974) . The nil-ductility transit ion temperature, determined by ASTM E208-69 (ASTM 1973) has been shown to -correspond to the transition of brittle (cleavage) to mixed mode (cleav age and microvoid coalescence) fracture which alway s is located at the toe region of the DT versus temperature curves .…”

“…Although the maximum constraint conditions are imposed for the section size of all specimens, the K it ransition curves occur at lower temperature s compared to NDT and DT transition due to loading rate effects . The Naval Research Laboratory references cover in detail the relationship between K j~, K id, NDT , and DT energy transitions for steels and their relationships to NDT and the fracture anal ysis diagram (FAD) (Goode , 1972(Goode , , 1974Goode and Huber , 1965;Goode et al, 1967 ;Goode , April 1973, November 1973;Jud y et al ., 1973;Pellini , 1967Pellini , , 1968Pellini , , 1969Pellini , , 1973Pellini et al, 1965 ;Pellini andPuzak , 1963, 1964 The cost of preparing 5/8-in . DT specimens is equivalent w the cost of preparing C v specimen s (ASTM E23-72).…”

Heat Effects of Welding

“…The most extensive statements in this respect can be obtained from the brittle fracture diagram according to Puzak and Pellini [406,407,411] (Fig. 255).…”

Gültigkeits‐ und Anwendungsbereich der Rißbruchmechanik

“…Der entscheidende Grund dafiir ist, daB der Bruch in der Ubergangs-und Hochlage der Kerbschlagzahigkeit nach groRer plastischer Formanderung eingeleitet wird, was den Verhaltnissen in der Konstruktion widerspricht. Es wird auf folgende Weiterentwicklung des Versuches gesetzt : Instrumentierung des Versuchs mit ringekerbter Probe zur 6,-und KI,-Auswertung [34] und die VergroBerung der Probe bis zur naturlichen Wanddicke (Drop Weight Tear Test) [21].…”