The Plastic Design of Latticed Portal Frames

The Institution welcomes as its President for the Session, 1961-62, Mr. F. R. Bullen, BSc. (Eng.), M.I.Struct.E., M.I.C.E., who takes office on the 5th October.

(1) . From 1956 to 1958 during the construction of certain prestressed concrete works in Lagos, it was noted from inspection of wire deliveries that a significant proportion of wire exhibited varying degrees of corrosion and - in particular - pitting. Various tests were carried out on samples of this wire prior to the tests described in this paper. The tests, comprising physical and chemical examination, static tensile strength tests and bend tests, were carried out both by a number of wire manufacturers and an independent tester. In due course the wire showing significant pitting (this generally being coupled with corrosion) was replaced by wire free from these characteristics. Subsequently, however, the matter was examined further and particular attention was directed to the effects of pitting on fatigue resistance as measured by ‘ push-pull ’ tests in an Amsler vibrophore. The results of these tests are reported below. Following a study of them, it was considered that further tests should be implemented on specimens which had corroded under controlled conditions with a view to ascertaining more general data than could be obtained from the necessarily ad hoc experiments on the samples of wire taken from Lagos. The results of those tests are reported separately in Paper B. A. Goldstein and C. F. Brereton

This paper reviews the economic and procedural effects on Structural practice of developments in present day circumstance. These have introduced a wide choice of structural forms accompanied by codified design rules and the mechanisation of construction techniques. L. R. Creasy