Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Global Supports Status W.O. Miller, R. Smith, W.K. Miller, G. Hayman, R. Baer HYTEC G. Gilchriese, E. Anderssen, N. Hartman, F. Goozen LBNL Outer Frame and End Cone

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Topics Identification of remaining frame issues –Needs: Confirmation and finalization of the global support frame design –Need information on outer support tube and connection of frame to support tube although largely decoupled by plates at end of frame to which mounts attach –Present approach Preparation of global support details drawings in process Updating of the frame dynamic analysis studies will be postponed until all information is firm Present results of testing with an end cone designed for the 500mm dia. Frame The easiest item first –Frame----where we are now and what we are doing in the near term

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Revised Mass Inputs Updating of the mass information is in process via Marco         Changes to 0.52 major addition Barrels(1&2) +disk services, along the outer frame up to PPO Current assumption is no weight sharing with outer support tube 10.4kg

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Service Ties Proposed general position of inserts on frame Approximate location of corner splice Also here?

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Frame Dynamic Solutions Comments on new mass inputs –New input agrees fairly closely to what has been used in our FE analysis: for example the barrel services on the end cone per side was 1.29kg, now is 1.2kg –Other individual items used at the CDR agree well –The new item of 5.2kg per side for services (barrel and disks), is shown as “along the outer frame up to PP0” Question: what is the mass distribution between frame and support tube? At the present we are holding off on any new frame solutions until issues are resolved with the integration of the frame with the support tube and we need this information by about mid-November –We are, however, proceeding with the preparation of the detail frame drawings and the tooling design –Our objective is to prepare for the PRR in February 2002

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector End Cone Developments (Sponsored by a DOE SBIR)

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Development End Cone Salient construction points –End Cone for 500mm frame design –P30Carbon-carbon facings, ~0.44mm –XN50/cyanate ester graphite fiber honeycomb, 4mm thick –YSH50 quasi-isotropic laminate for outer supports and inner tabs Static tests –End Cone is mounted on an optical table, using the 8-mounting tabs –Force is applied and the deflection monitored with holographic imaging system White paint on short tab for holographic measurements

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector End Cone Components Panel bonding fixture End cone components Cone Bi-panel testing Emphasis on correlations with predictions

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Static Test –Load application on inner mounting tabs –Compliance recorded for mounting tab of 17.6  m/N, load applied 2.223cm from end of tab –Slight error noted in fringe counting over large deflection range –Approximately 78  m’s for 1lbf(4.448N) load –We note that the fringes are smooth and continuous over the Bi-panel joint indicating proper structural behavior Bi-Panel Static Test

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector End Cone TVH Testing Static Load Tests –Concentrated force applied to short and long tabs For long tab, force was applied at two radial locations –1.5875cm,  m/N –2.8575cm, two values  m/N and  m/N For short tab force was applied at one location –0.635cm—two values  m/N and  m/N Analysis –Can not explain data for the long tab, force applied at cm and cm, performed on separate tabs as well For a given tab, deflection does not scale as one would expect Observations –However, fringe patterns appear to be smooth and continuous, indicating proper structural behavior Long Tab Short Tab

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Long Tab Compliance Long tab under increased loading –Blow-up of fringe region –We see a very localized fringe where tab joins the sandwich –The localized pattern is suggestive of local bending of the facings The FE model may be falling short of correctly depicting the compliance at this interface Current thinking is that we need to improve the load transfer in the region of the tab connection to the end cone. Blue lines are the approximate edge of the sandwich facing

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector End Cone TVH Results Results –Decent comparison between measured predicted only exists for the inner short tab –No reasonable explanation exists at this point in time between predicted and measured data for the end cone on the long tabs –Tests were repeated on the long tab at a location of cm, using dial indicator, and similar range in values was noted –More testing is needed

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Axial Compliance A possible question----how efficient is the conical sandwich structure? Consider the deflection of a short tab without sandwich panels on either side. –For 1kgf, the strip deflects cm, at point of load application, a compliance of  m/N (versus 1.733) –Compliance of a short strip without sandwich panels has greater compliance. Effect of the panels is quite pronounced, which is desired Short Tab Continuous over the joint Strip only Units cm

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Next, look at the deflection of a long strip without sandwich panels on either side. –For 1kgf, the strip deflects cm, at point of load application, a compliance of  m/N (versus ~16.5) –Compliance of long tab without sandwich panels has 6.1 greater compliance. Again, the panel effect is substantial Axial Compliance Full cone Long tab Strip only Units cm

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Tangential Compliance Objective: figure of merit for R  compliance –Load applied to short tab causing a rotation about a corner –Deflection amounts to.0396  m/N or 0.44  rad/N of rotation at the applied load Tangential compliance quoted is for one tab: –For outer shell the tangential compliance goes down by factor of 8, with a shell connected to all 8-tabs Applied load Units cm

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector Long Tab, connected to three shells End Cone Tabs Short Tab, connected to one shell Stiffness of tabs will be enhanced to some extent by connection to the shell, multiple shells in the case of the long tab

Global Supports Update W.O. Miller October 2001 US ATLAS Pixel Detector End Cone Summary The end cone (500mm dia) tests confirmed our expectations –Axial stiffness of the short tabs is quite high-7*10 5 N/m (4011lbf/in) per tab Axial natural frequency of the barrel region would meet or exceed the 100Hz goal However, the analysis of end cone test results is still an active SBIR item –Our desire is to understand what caused the deviation between predicted and measured results for the long tab Simple material tests are planned to ensure the appropriate modulus is being used---although this is not expected to be a significant contributor A further evaluation will be made of the connection (FE model) between the sandwich structure and the solid laminate A design is under consideration that should simplify the construction of the joint between adjacent flat panels and possibly improve the joint load transfer With regards to ATLAS, we just need to verify that our CAD files properly reflect the interface control drawing for Cone A and Cone C. We are still on track for the PRR in February 2002