The project has been concerned with the residual life prediction in metal matrix composite materials (MMC). The overall purpose was to provide new methodologies and tools for damage mechanics, damage detection and reliability engineering in MMCs and to derive consistent design and product control procedures. Particulate reinforced and short fibre reinforced composites have been considered.
Two specific applications have been considered for validation and demonstration purposes: the inter-valve seat of cylinder heads, and the connecting rod. The selected applications are intended to verify and quantify the applicability of the new methodology to those components where high temperatures, and fatigue phenomena are experienced.
Both analytical and experimental work has been carried out. The main results obtained within the framework of the research performed include:
full characterization of the microstructural, macromechanical, fatigue and thermal fatigue behaviour of the materials, and measurement of the residual stresses due to the machining process;
assessment and calibration of methodologies for non-destructive examination of the materials and for the assessment of damage initiation and growth in the materials;
development of design tools including predictive probabilistic and deterministic models for the reliability analysis (the models developed can be used as design tools for mechanical components, by allowing the engineer to assess, early in the design phase, the probability of failure of the component under fatigue loading);
manufacturing of two prototypes of automotive components and performance of an extensive test programme (the results of this work have provided a full set of results under real loading conditions which have been used as a basis for validation of the proposed methodology on real components).