I have a question regarding the degradation in mechanical properties of 6061-T6 aluminium alloy at elevated temperatures.
The application involves operation at 250degC which creates quite a severe reduction in the strength properties. If I review published data (ESDU, MMPDS-4 etc) there are...
I have an empirical formula developed by the RAE for calculating the equivalent static loading from a birdstrike. The report details are:
The Design of Leading Edge and Intake Wall Structures to Resist Bird Impact
Report No. RAE TR72056
I have not been able to obtain a copy of this report and...
If I am designing a vibration fixture for testing in the vertical axis, does it matter if the test item is mounted upside down?
Some opinions say yes, since gravity is adding a 1g downward acceleration.
My opinion is that the feedback loop in the vibration controller will neutralise this and...
If I run a stress analysis with a random vibration input spectrum, the output stresses will be in Grms (1-sigma), and therefore for a fatigue analysis I can also determine the 2-sigma and 3-sigma stresses. However, the thing I'm uncertain about is how to determine the number of cycles at each...
I have a query related to the DO-160 Helicopter Vibration test procedure. A sine sweep has been conducted on a piece of equipment that has identified several closely spaced resonances within the 1st sinusoidal test band. The test house is conducting 4 separate sine dwells at the 4 highest...
Can I ask a couple of questions about Fatigue Modifying factors when performing a fatigue analysis of an aluminium component:
1. Temperature Factor - I have seen it recommended that a temperature factor of 1 is applied for temperatures up to 450degC. Whereas I have also seen it proposed that the...
I'm doing some stress analysis for a filter system that is subjected to 1,500,000 pressure cycles from 0 to 260bar, with a pulse rise rate of 100,000 to 200,000psi/sec. Previous analyses have been carried out assuming a steadily applied load repeated for the required number of cycles. However...
