The Need for Traceable High Shock Vibration Calibration. APMP TCAUV Workshop

Transcription

1 SPEKTRA Schwingungsechnik und Akusik GmbH Dresden Calibraion Sysems Special Equipmen DKD Laboraory Environmenal Tesing The Need for Traceable High Shock Vibraion Calibraion APMP TCAUV Workshop The Curren Siuaion Why do we need raceable High Shock Calibraion? Calibraion of acceleromeers in he following applicaions: Aerospace Airspace Miliary Typical acceleraion g Environmenal esing: Endurance esing of MEMS srucures Failure invesigaions of MEMS srucures Typical acceleraions g Research work: Medical/Biological/Physical/Chemical research Typical acceleraions > g 2

2 The Curren Siuaion High g Shocks in Pracice Calibraion of acceleromeers ha are used in Aerospace applicaions: Invesigaion of sage separaion mechanisms of rockes Apollo 11 firs sage separaion Typical acceleraion up o g 3 The Curren Siuaion High g Shocks in Pracice Calibraion of acceleromeers ha are used in Airspace applicaions: Invesigaion of impacs due o collisions of foreign maerial (bird srike) composie maerials Helicoper IAF UH-60 afer bird srike F16 afer bird srike Typical acceleraion up o g 4

3 The Curren Siuaion High g Shocks in Pracice Calibraion of acceleromeers ha are used in Miliary applicaions: Deep peneraion bombs, invesigaions of ineracion of explosives and solids/fluids Typical acceleraion up o g 5 The Curren Siuaion High g shocks in pracice Environmenal esing Endurance esing of MEMS (Micro Elecro-Mechanical Sysems) srucures (background is high mechanical sress while handling/mouning procedures) Failure invesigaions of MEMS srucures (sicking effecs) Typical acceleraions g 6

4 The Curren siuaion High g shocks in pracice Medical/Biological/Physical/chemical research Invesigaion of shock wave herapy Invesigaion of conac forces beween small ( µm) paricles and surfaces Typical acceleraions > g 7 The Curren Siuaion The ools o provide high acceleraions Wha shock exciers are available? Hammer-Anvil-Principle - SE-210 SP-LS Low Shock Pendulum 10 gn 200 gn - SE-201 PN-LMS Low Medium Shock 5 gn 15,000 gn Hopkinson-Bar-Principle - SE-220 HOP-MS Medium Shock 20 gn 4,000 gn - SE-221 HOP-HS High Shock 1,000 gn 100,000 gn - SE-222 HOP-VHS Very High Shock 5,000 gn 200,000 gn - SE-222x HOP-VHSx Ulra High Shock 10,000 gn 500,000 gn 8

5 The Curren Siuaion The ool o provide high acceleraions The Hopkinson-Bar-Principle: based on he propagaion of compression waves in a solid bar wave is excied by a mechanical impac reflecion of wave moves end of he bar acceleraion of DUT full sine acceleraion a[m/s²] a[m/s²] F[N] F[N] F F Displacemen u(x,) Displacemen u(x,) [s] x 10-4 [s] x 10-4 a a MP MP 1 MP 1 MP 2 MP 2 MP n n 9 The Curren Siuaion Classical Hopkinson-bar Working Principle Linear Sage Barrel Hopkinson Bar p +/- Projekilesop Projecile Force impac provided by a projecile impacing he bar Projecile acceleraed wih pressurized air Kineic energy of projecile conrolled by movable projecile sop All auomaic operaion possible Good reproducibiliy 10

6 The Curren Siuaion Classical Hopkinson-bar How o increase he acceleraion ampliude? a.increase he force ampliude Limied by maerial properies of he projecile and Hopkinson bar (inelasic deformaion) b.decrease shock duraion due o df()/d he acceleraion ampliudes increases if he shock duraion decreases F MP1 MP2 MP2 a () Displacemen u(x,) MPn 1 MPn 2 c0 df() E A d a difficul o conrol; depending on surface ineracion beween projecile and bar c 0 = speed of sound E = Young s modulus A = cross secional area of bar 11 The Curren Siuaion Classical Hopkinson-bar How o increase he acceleraion ampliude? c.change c 0 /E Tianium has already very good maerial properies d.decrease A he smaller A, he higher he possible acceleraion ampliude limied by he minimum A ha is required o moun he DUT a he bar F MP1 MP2 MP2 a () Displacemen u(x,) MPn 1 MPn 2 c0 df() E A d c 0 = speed of sound E = Young s modulus A = cross secional area of bar a 12

7 The Curren Siuaion Technical Daa SE-221/222 HOP-HS/VHS Type of Exciaion Sinusoidal Shock Shock Ampliude HS m/s² o m/s² VHSx m/s² o m/s² Pulse Widh HS 50 µs PWFS VHSx 20 µs PWFS DUT mass Up o 30 gram 13 The curren siuaion Used reference sandards Srain gauges Displacemen u(x,) Force Inpu Hopkinson Bar Srain Gauge DUT () () 20 * d a c d c 0 = speed of sound 14

8 The curren siuaion Used reference sandards Laser Vibromeer Displacemen u(x,) Force Inpu Hopkinson Bar DUT Laser Vibromeer a () 2 u 2 () v () v ( )= measured velociy 15 The curren siuaion Experimenal reference sandard Displacemen u(x,) Force Inpu Hopkinson Bar DUT u () r () * 2 r () u () * 2 = Poisson's raio 0.34 Deformaion r() Preliminary resuls of curren measuremens: linear relaionship beween radial deformaion r() due o compression wave and velociy du()/d a he DUT end of he Hopkinson bar 16

9 The curren siuaion Experimenal reference sandard High-g-Shock gn, PWHS 10 µs 17 The curren siuaion Used reference sandards Transverse Deformaion expeced working range Srain Gauge sable working range mechanical problems Laservibromeer meas. range 10 m/s meas. range 20 m/s x 10 3 g n 18

10 The curren siuaion Used reference sandards Transverse Deformaion expeced working range Srain Gauge sable working range mechanical problems Laservibromeer meas. range 10 m/s meas. range 20 m/s x 10 3 g n 19 The Approach Used reference sandards Unil oday we use wo reference sandards, he laser vibromeer and he srain gauge The measuremen range of he laser vibromeer is oo small The srain gauge is mechanically no sable above gn I means ->wih he sable working range, we are limied o abou gn In he range from gn up o gn we are on research level Traceabiliy only is given up o gn -> 2% of he working range 20

11 The Approach Collaboraion of NMI and SPEKTRA Conclusions SPEKTRA is able o develop dedicaed calibraion exciers and also measuremen hard- and sofware. Wha we canno do is he developmen of a High Shock Laser Vibromeer on primary level. The idea is a collaboraion in beween NMI s and SPEKTRA 21 The Approach Collaboraion of NMI and SPEKTRA TASKS SPEKTRA: Providing shock exciers wih he following specificaions: - Acceleraion signals up o gn - Velociy ampliude approx. 40 m/s - Frequency conen approx. 100 khz TASKS NMI: Measure acceleraion signals simulaneously wih differen Laser mehods on primary level - Comparison of he differen Laser mehods - Validaion of he differen mehods - Transfer of he uni acceleraion o he Srain Gages or analogue Laser Vibromeer 22

12 The Approach Collaboraion of NMI and SPEKTRA Wih his work a compleely new field of research and developmen could be locked up. This work would be a grea conribuion o his field of merology. Thank you for your aenion! 23 SPEKTRA Schwingungsechnik und Akusik GmbH Dresden Calibraion Sysems Special Equipmen DKD Laboraory Environmenal Tesing Heidelberger Sr. 12 D Dresden, Germany phone fax sales@spekra dresden.com dresden.com