IIW History 1948-1958

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This method, which was approved by the majority of the members of the Commission, has been proposed to ISO/TC 44 Sub-Commission z which has accepted it as regards the stresses d j_, -rJ_ and -ru but which has asked that, for the stress cr1 f , further checks should be carried out before the formula is adopted in the most general sense. The corresponding experiments are now being carried out in the various member countries. In addition to the tests already undertaken to study the strength of a weld seam in relation to the direction of the stress, Professor VREEDENBURGH has undertaken advanced experimental studies, on a statistical basis, to establish definite data concerning the strength of joints with longitudinal seams. The preliminary phase of these tests is mentioned in documents XV-47-46 and XV- 64-57; in the tests, consideration is given to all possible variants in the form and execution of the joint; this constitutes a happy application of statistical methods and shows the advantages which can be drawn from them as regards the number of tests to be carried out. Apart from the usual methods mentioned above, the second aspect of the problem, that is the manner of calculating the stresses in seams in relation to the known external loading, was subsequently studied; a series of standard joints, whether simple or complex, which do not fit into usual strength of materials methods, is at present being examined in order to find simple hypotheses which are likely to make these methods applicable. In particular, consideration is given to simple assemblies which include both longitudinal and transverse weld seams, the axes of which are situated in the same plane and which are submitted to stres~es acting in this plane itself; more complex joints with weld seams placed in several planes at right-angles to one another are also considered. Natur– ally, a check will be carried out experimentally to see whether the hypotheses thus developed are firmly based. Sub-Commission C started work in 1955 ; the purpose of its work is to establish a series of recommendations likely to assist the draughtsmen responsible for developing a design for welded construction . Simple principles, illustrated by typical examples, will be given in order to allow users to benefit from the advantages resulting from the application of welding and to avoid the disadvan– tages which the application of welding may also entail. In its work, the Sub-Commission is making use of the work accomplished by other Commissions of the IIW or is asking advice and suggestions from these Commissions ; it is, indeed, impossible to lay down rules for the design of welded constructions without taking into account, for instance, the parent metal, the results of shrinkage or fatigue phenomena.

Sub-Commission B (Calculation of welded constructions subject to dynamic loading) will begin its work during the year 1957-58 in close liaison with Com– mission XIII (Fatigue testing). The working group on the influence of the difference of the yield point between the parent metal and the weld has already considered important experi– mental results which, so far, have not shown that any disadvantages result from this difference in yield point. Further investigations are being carried out.