Optimised design is an indispensable prerequisite for safety, reliability and e conomic usage of a large scale of industrial components and plants. In order to make the most of service life and in view of the possibility of life time exte nsion all relevant parameters and loadings influencing the usage have to be tak en into account during design. Recent efforts for fatigue design on European l evel (Eurocode 3) have led to fundamental changes in approach and some signific ant improvements, but have also highlighted important deficiencies, notably: - Iack of design data for castings, at a time when their industrial use is incr easing; - conflicting evidence on the effect of temperature over the range of interest (-50 to 400°C); - poorly defined rules for very low-cycle fatigue; - an urgent need to provide the link between detailed stress analysis methods (eg FEA) and fatigue data generated using simple small-scale specimens of the k ind used to provide most current design data. Apart from safety issues, these highlight a growing mis-match between industrial practice and design specificat ions, which limit the designer's ability to take full advantage of new material s and analytical techniques. The industrial objective is the development of an advanced design and reliability method for low-cycle fatigue (LCF)-loaded comp onents operating in the temperature range of -50 up to +400 °C based on improve d fatigue data and verified by representative tests with complex service type l oading conditions (feature tests) and advanced numerical computations. It is proposed to develop new low-cycle fatigue design procedures mainly on the basis of detailed testing and analysis of full-scale structural components fabricate d in steel or cast iron. These will be subjected to realistic fatigue loading c onditions, including multiaxial or combined loading if appropriate. The structu ral components will be selected from a range of industries utilising pressurise d equipment on the basis that design improvement or optimisation would lead to significant improvements in safety or economy. The structural tests would be an alysed using FEA and available fatigue data but, where necessary (eg castings), new data would be generated. To facilitate application of the methods develop ed, a Low-Cycle Fatigue Computer Aided Design (LCF-CAD) system will be produced and commercialised.
Funding SchemeCSC - Cost-sharing contracts
PA4 8DJ Renfrew
CB1 6AL Cambridge