κέλῡφος and καλύπτω

Though καλύπτω ‘cover’ is normally and correctly associated with *√ḱel- ‘cover’, the origin of the entire base καλυφ- remains unclear. The basis of clarification consists in an appreciation of the formally resemblant s-stem κέλῡφος, whose meaning ‘sheath, case, shell, husk, pod’ has invited comparison. The author therefore hypothesizes that the bases καλυφ- and κελῡφ- include related layers of nominal material. Starting from an originally adnominal *ḱel-ó- (> OIr. cel ‘death’), the author reconstructs the u-stem substantive *ḱó/él-u- ‘covering’, for which the evidence of Proto-Germanic *χlewa- ‘shelter’ and Greek κολεόν ‘sheath’ is adduced. The element in -φ- is then argued to reflect a nominalized form of *√bʰuhx- ‘become’ qua light verb of an anti-causative periphrasis whose originally acrostatic heavy member *ḱó/él-u- was employed as a predicative instrumental *ḱéluh₁ eventually fossilized as an indeclinable adnominal eligible for use as a First Compound Member (FCM) (> κέλῡφος). By comparison to the allomorphically archaic πόλις ‘city’ (gen. πόληος), the author finally argues for the paradigmatic renewal of *ḱó/él-u- (> > *ḱól-u- : ḱl̥-u̯- : ḱl̥l-éu̯) and the eligibility of its weak stem as first member of a compound from which was formed the *-i̯e/o- present ancestral to καλύπτω.

Case shell joint at short-term creep

A technological system and proportions for the technology computation of shell pressure joint are offered. A method of work balance is used. The equations of material state under conditions of the plasticity and short-term creep are adopted. The results of computation and technological works are given.

Fatigue Life Prediction of Welded Case Shell on Aeroengine under Combined Internal Pressure and Axial Loads

Stress and fatigue analysis of welded case shell on aeroengine under combined internal pressure and axial loads using elastic-plastic finite element has been performed. The results show that the largest stress concentration appears on the mutational cross section of the fixture seat and fixture fringe structure some distance from the weld toe. The positions with the weakest fatigue life locate at the fixture fringe close to the weld toe of girth joint, and also appear at the ring closed weld of the case shell middle.