To take full advantage of and learn from overall structure of existing engine case, this paper presents parameterized, object-oriented method and similarity retrieval algorithms. A case library of parameterized engine overall structure is established by “top-down” master modeling method. On this basis, the management of engine parameters in case library is achieved, which built a foundation for the rapid design of new program at stage of overall structure design.

In this paper, the probabilistic compliance methodology for damage tolerance design of thicker composite structures were investigated, and the research results show that for the composite laminates withstanding impact energy below 90J, if it cannot produce barely visible impact damage (BVID), then using the probabilistic methodology can meet certification requirements of damage tolerance.

The environment which can have a great effect on the composite aircraft structure performances must be considered during the design and certification process. In this paper, the extreme temperature and humidity span of the worst environment conditions in aircraft structure design and certification are investigated, and some test methods involving environment influences are also discussed. The studying results can be used in design and certification for environment influences of composite aircraft structures.

Monolithic Nd: YAG lasers pumped by laser diodes have been widely used in precision measurement fields due to its low frequency noise and intensity noise. Previously, people found that the intensity noise of the pump laser would affect the frequency noise of the Nd: YAG lasers, but the cause has not been well explained so far. In this paper, we propose that this effect is thermally induced. The experimental results agreed well with the theoretical model predictions in up to 60 kHz frequency range. The finding can provide ideas for further reducing the frequency noise of Nd: YAG lasers. We get about 300 Hz linewidth in NPRO laser pumped by single laser diode.

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