PBX 9502 Multimode Damage Accumulation Cycles-to-Failure Study
In FY13, we performed a detailed cycles-to-failure study of PBX 9502 using 3- point bend specimens. In that study we examined the effect of temperature and cyclic frequency on the failure behavior of PBX 9502. We identified cycles-to-failure curves for samples tested at -20°C, ~19°C and 50°C and at cyclic frequencies of 0.0001 up to 1-Hz. We also did cyclic conditioning of parts in an effort to establish damage accumulation criteria that could then be used in predictive models. As follow-on to that work, in FY14 we have added multimode cycles-to-failure to our test suite. Work this year re-established the baseline cycles-to-failure behavior of the PBX 9502 material tested round ~19°C at 1-Hz and also looked at damage accumulation under a multimode loading environment. This fresh baseline development was performed to remove any time related or test rig related variables. The multimode loading was done because real-world applications are not mono-modal and we desire for our predictive capability to be robust and include more complex, realistic scenarios. In the following sections we briefly describe the test setup, we provide a summary of the new baseline results and we show the multimode cycles-to-failure data and how it compares to the mono-modal test data.