M1Celldeflectiontestreport-VLTSurveyTelescope：M1細胞撓度檢測報告-VLT巡天望遠鏡

1、VST Project60e0e6e5c9133fd54eca036ccff1cae3.pdfRev.: 1.0Date: 2022/2/10Pag. 17 of 17VST ProjectRecovery PlanM1 Cell Deflection Test ReportDoc. : VST-TEST-OAC-22300-2055Issue: 1.0Date:10-2月-22NameDateSignaturesPrepared byF. Perrotta,M. Brescia, L. Ferragina28 May 07Approved byReleased byRevisionsIssu

2、eAuthorDateSection/Paragraph AffectedReason/Initiation/Documents/Remarks1.0M. Brescia, F. Perrotta, L. Ferragina28/05/2007AllFirst issueIndex1Abbreviations and Acronyms42Introduction53Test Equipment System54Test report74.1Test Results134.2FEA Analysis14Table IndexTab. 1 Abbreviations and acronyms4Ta

3、b. 2 Set of measures13Tab. 3 Set of measures, compared with FEA Data13Tab. 4 Set of measures13Figure IndexFig. 1 M1 cell backside view, with loading central plate and PTFE support pads6Fig. 2 the 3 PTFE supports and glue7Fig. 3 positions of PTFE supports with respect of the corrector interface surfa

4、ces8Fig. 4 position of measuring sensor near to the central hole of the cell9Fig. 5 the whole measurement system ready for acquisition10Fig. 6 positions of the two measurement sensors11Fig. 7 zoom of the positions of the measurement sensors11Fig. 8 contemporary weight (Kg) and deflection (mm) values

5、. The sensor on the right is the central one12Fig. 9 M1 Cell test model14Fig. 10 M1 Cell actuator support plate displacements along optical axis (units are mm)15Fig. 11 M1 Cell central sensor location and calculated displacement15Fig. 12 zoom on M1 Cell central sensor location and calculated displac

6、ement15Fig. 13 M1 Cell lateral sensor location and calculated displacement16Fig. 14 zoom on M1 Cell lateral sensor location and calculated displacement161 Abbreviations and AcronymsA & AMeaningFEAFinite Element AnalysisFEMFinite element ModelingOACCapodimonte Astronomical ObservatoryVSTVery Large Te

7、lescope Survey TelescopeTab. 1 Abbreviations and acronyms2 Introduction This document provides the full description of the deflection tests done on the M1 cell, in order to verify FEA calculations and to investigate the overall performances of the active optics axial actuator system in case of high

8、displacement of the M1 cell internal structure under mirror and corrector load in operative conditions.3 Test Equipment System The schematic view of the M1 cell, the circular loading disc and the positions of the three PTFE pad supports is shown in Fig. 1. The following calculations have been taken

9、in consideration:Resistance of PTFE to the compression with 1% of deformation - Method ASTM D 695Area 1 pad in PTFEApplicable Force on 1 pad in PTFETotal applicable force to the cell with 3 pads in PTFE d=40mmIn order to perform the tests, the following equipment has been used: M1 Cell positioned on

10、 the floor and turned upside down. Steel circular plate (rusted) (weight 90 Kg, diameter 880 mm) Three PTFE pads (diameter = 40 mm, thickness = 20 mm), used as interface between loading and cell plates Steel bar positioned inside the cell, not in contact with actuators support plate Measuring system

11、: Mitutoyo displacement sensor (accuracy = 1 m)Fig. 1 M1 cell backside view, with loading central plate and PTFE support pads4 Test reportFig. 2 the 3 PTFE supports and glueFig. 3 positions of PTFE supports with respect of the corrector interface surfacesFig. 4 position of measuring sensor near to t

12、he central hole of the cellFig. 5 the whole measurement system ready for acquisitionFig. 6 positions of the two measurement sensorsFig. 7 zoom of the positions of the measurement sensorsFig. 8 contemporary weight (Kg) and deflection (mm) values. The sensor on the right is the central one4.1 Test Res

13、ultsThe following tables report the values of load and deflection as measured during test. The first set of data is also compared with FEA analysis, taking into account the exact correspondence between load and measurement points in the cell.ScaleKgcentral sensormmlateral sensormm1150,0410,0333250,1

14、150,0876450,2290,1517750,2760,1788900,3160,20210100,360,22411350,4040,24712500,4440,26713450,4780,28614350,5110,30815850,6210,343Tab. 2 Set of measuresScaleKgcentral sensormmlateral sensormmFEA Data (central)mmFEA Data (lateral)mm15850,6210,3431,030,4Tab. 3 Set of measures, compared with FEA DataSca

15、leKgcentral sensormmlateral sensormm1100,0510,0422100,0960,073300,1460,1174050,180,1275400,2220,1366700,280,1867700,3220,2119200,3850,26610900,4580,31412100,5060,35313600,5680,39215700,6550,458Tab. 4 Set of measures 4.2 FEA AnalysisFig. 9 M1 Cell test modelFig. 10 M1 Cell actuator support plate displacements along optical axis (units are mm)Fig. 11 M1 Cell central sensor location and calculated displacementFig. 12 zoom on M1 Cell central sensor location and calculated displacementFig. 13 M1 Cell