TABLE OF CONTENTS ROBERT E. MELCHERS
Centre for Infrastructure Performance and Reliability
The University of Newcastle, Australia, 2308
E-mail: rob.melchers@newcastle.edu.au
The basic concepts in structural reliability analysis using probability theory are overviewed and the important effect of structural deterioration is noted. For representation of material loss due to corrosion and for pitting corrosion appropriately accurate models are required. These should account for the many variables involved in natural environments. Recently introduced probabilistic phenomenological models for marine immersion corrosion are then described both for general and for pitting corrosion. These show that the nature of the corrosion process changes from being controlled by oxygen diffusion and later by anaerobic bacterial action. This change has important implications for longer-term prediction of general corrosion loss and for maximum pit depth. A summary is given also of the effects of steel composition, water velocity, salinity, pollution and season of first immersion.
In the design of new structures and the assessment of existing structures, long-term durability increasingly is becoming an issue of interest. This is the case both for offshore structures and shipping and for land-based structural systems. Because of the uncertainties involved it is appropriate to employ structural reliability methods. In addition to models for the applied loadings Q these require probabilistic models for the structural strength properties R( t), here shown as a function of time since typically structural strength and capacity tend to deteriorate with time. This must be considered in any reliability assessment. Thus models are required...
