Sharon,

 

I would like to take the opportunity to explain the matrix I included for yesturday's telecom.  Even with the additional factor of 1.25, the conclusions are very much the same.  See the attached, updated, matrix.

 

The loads, by themselves, are not very significant.  They are based on all the flexures, in all the locations, with several launch configurations, and a MUF included.  They do, however, provide a means of defining a requirement, and allow us a simple means of controlling a qualification test.  But, they do not imply anything beyond that.  As a design engineer, I am more concerned with ensuring that the structure we design will survive the launch environment.  Ultimately, this means that I am concerned about the stress in the part, and enveloping the critical stress conditions through testing.  The matrix that I sent, shows that we envelope the critical CLA predicted stress levels for both flexure types, in a combined manner, even though we do not exceed the combined CLA loads, per the requirement.  So, the point of this matrix demonstrates that any test we design to meet the combined load requirements of the CLA will not be as severe as the random vibration static equivalent tests performed to date, so long as we don't use the random vibration test configuration to provide the load.

 

With that said, we intend to re-design the test to meet CLA specified combined loads for both flexure types.  I believe that we can do this by selecting the proper axis to test and removing two flexures, as required.  This will put more shear load into the flexures under test, without adding axial load that will overstress the hardware (analysis will ultimately determine the success of this test).  Since this is a change of scope, I will put together a quick plan to accomplish this and obtain approval from Tom Borden to proceed.

 

I hope that this makes a little more sense now.  If you have any questions, please contact me.

 

Thanks, Erik  

 

Erik A. Swensen

Deputy General Manager, HYTEC Engineering Inc.

110 Eastgate Drive

Los Alamos, NM  87544

 

Phone:         (505) 661-4991

Fax:             (505) 662-5179

Web:            http://www.hytecinc.com/hei/index.html