BENEFIT OF PARTLY DISPLACEMENT CONTROLLED CONDITION IN SAGBEND

摘要

Some codes like BS8010 and DNV-OS-F101 distinguish between load controlled condition or displacement controlled (or strain based) condition. Even though the principles are clear, it is often hard to determine the difference in practice. A displacement controlled condition allows a higher utilization and is therefore beneficial, and can be applied provided that the condition can be classified as a displacement controlled condition. Many projects have had intense discussions on this matter during the last 15 years, however, without much progress. The objective of this paper is two-fold. First it will show that a discussion on load controlled versus displacement controlled is of limited value. The discussion should rather be on how to take benefit of a partially displacement controlled condition. Second, the paper gives a suggestion on how to allow for a partially displacement controlled condition, also determining the degree of displacement control. The suggestion is supported by specific FE-calculations.