Title of Invention

A PORTABLE DEVICE FOR AUTOMATIC NON DESTRUCTIVE TESTING OF PANELS

Abstract

This invention relates to a portable device for non-destructively testing flat panels particularly sandwich panels. Debonding or improper bonding of panels may be noticed by processing signals obtained on tapping the panel. The device consists of a drivable plotter connected to a computer .Signal sensing means, signal processing means, signal storing and displaying means are also provided for collecting test data. The pen plotter has a force guage movable up and down on the panel on receiving commands from the computer to generate signals which are processed, stored and displayed.

Full Text

This invention relates to a portable device for automatic non destrue t ive testing af pane 1 s wh i.c h i s par ti cu 1 ar 1 y hut nat e x c 1 u s i v e 1 y a p p 3. i c a b 1 e i n t e s t i. n g a n d i n spec t i n g d e b o n d i n q between sandwich panel s ■ S t ruc tura 1 pane 1 s of sandw.1 c:h ty pe construction find extensive use in aerospace i.ndusttj-y « Sandwich type panels are conventionally formed by j oining f a c e s h e e t s a rid c o r e m a t e r i a 1 wit h B U a. t a b 1 e a d h e s ives t o f o r m a honeycomb 1 ike? structure „ In sandwich panels,» debonding b e t w & e r "i the fa f,;; e s h e e t a n d c o r e m e m b e r o c c: u r f r e q u e n11 y ,, n e cess.it a t i n g p e r i o d i c c i "i e c k s t o r e c t :i f y d e f e c t s * Conven t i onally ^ixc h inspec t i ons a re c: a r r i. ed ou t by po i n t to p o i n t t e s t i n g m a n u a 11 y * A e r o s p a c e i n d u s t r y r e q u i r e s 1 a r g e pai "iell i n g ex tend ing over a c on s i. d er a b 1 e ar ea* Manua 1 i. n s pec t i on and testing of such large panels a.r& problematic ? time consum i n g and 1 a bou r i n t en s i v e - T he po r t a b 1 e d ev i c e o f t h i s invention has been deve1oped for simp1yfying the testing process for 1 arge tapping of good and bad areas of panelling is different. It has been ©stab1ished that amp1itude» pu1se duration and f requenc y domain parametens of f orc e and acoust ic sign a 1 s are u s e f u 1 i n c h a r a c t e r .1 s i n g a n d i d a n t i f y i n g g o o d a n d b a d a r a a s of sandwich panel 1ing* The device consists of a flat bed plotter which has a pen plotter drivatale in the X--Y axis of «a flat bed« The pzm h o 1 d e r h a s a d i g i t a 1 p e n p 1 o 11 e r w h i c h i s p r o g r a m m e d t o b e positioned within the pen holder - The pan holder may be f ixed t o a n y desired p o i n t f o r t e s t i n g a n d i n s p e c t i o ns - 1" h e p e n ho 1 d e r a s s em ta 1 y a 1 sa h a s a f o r c e g a u g e p r e f e r r a b 1 y a p 1 e s o e 1 ectrie force gauge sue.h as a transducer for making 1 ow velocity impacts on the panel to be tested - The pen holder h ix m plot t e r a s sem b 1 y ;i, s h e 1 d i n p o s i t i on w i t i"i t h e *■1 e 1 p o f fixing means such as vacuum cups,, Control means are also p r ovi.de d t o d r i v e a s o 1 o n o i d a s s o c i a t e d w i t h 1h e p 1 o 1t e r assembly which in turn provides pmt up and down commands to the p^n holder - These control means may be an analog input/ output 'add - on card' residing in a PC - The ana1og output generated by this add on card provides necessary voltage to the solenoid to drive the p^n holder up i-und down- As already sta ted a f orce gauge w h ich may be a t r ansd uc e r assoc ia ted with the plotter / holder assembly provides the necessary voltage output to the analog input channel of the add on c^rd of the computer. . The plotter / holder assembly is connected to sensing means such as an analog digital converter to c a p t u r e t h e f o r c a i m p u 13 e f r o m 111 © t r a n s d u d a t a t o t h e c o m p u t e r f o r d i B p 1 a y i. n a v i d e o g r a p h i c. m o n i t o r « A c t i v a t i o n o f t h e f o r c © g u a g e t r a n s d u c. e r p r o v i d e B t h e requi si te t rigger for t he ana 1 og d i gi ta 1 conver ter to s tar t c a p t u i'* i n g t he s i g n a 1 s - T hes© B i g n a 1 s p r o v i. d e pe a k a in p 1 i t ud e and time duration which are the basic parameters required for c h a r a c t e r i s i n g t h © q u a 1 i t y o f t hi e a d h © s i v e p a n © I » S i g n a 1 s g e nerated fro m the pan © 1 s a r e p r o c esse d b y m e a n s o f i:» i g n a 1 c ond i tioners and the ana 1 og d ig i ta 1 Bigna 1 con vertors wh ic h m a y b e fed t o t h e c o m p u t e r t a b e s t o r © d a n d / o r m a y b e displayed on conventional cathod say ■ osci1lograph for e f f e c t i n g cor rec t i v © me a s u r e s w h © r © r a c:| u i r © d . T h © a r id h o 1 d i n g t h e p © n p 1 o 1t e 1*- i s cJ r i v e n b y B t © p p © r m o t o r i n t h © X Y axis of the bed. Th© stepper motor may be connected to the PC which cantro1s the operations* T h e p o r t a b 1 e dB'viC€2 for a u t o«i a t i c n on d © B t r u c t i v © I: © s t i n g o f pan©Is according to this invention comprises a flat bed plotter c on s i & t i n g o f a d r i v a b 1 © pasn p 1 o 11 e r p r ov i d e d w i t h fore© guag©♦, contro 1 means commanding up i^and down movements of the said pen plotter ^drive mB&n%> to drive th© said plotter in th© X Y axis of ' the said panel*, fixing means to fix the said plotter on any desired location of the said panel j, the said plotter having connected thereto., signal sensing means, signa 3. processing weans , signa 1 storage and signa 1 d i s p X a y m e a n s t. o s e n s e ? p r o c e s s , s t o r e a n d d 1 s p I a y t h e s i g n a i s r e c e i v e d t h e r e f r o m* T h e d evice? a n d t h e m e t h o d of operating the device according to this invention wi11 now be desc r i bed wi th ref erence to the s ing 1 e f iqure in the a c c o in p a n y i n g d r a w .i n g s - The figure illustrates the device according to this invention as mounted on a sandwich panel (S.P-) to he tested* Referencing 1 e11er (PH) indicate tfte pen ho 1 der and p 1 o11er mounted on a movab1e arm (MA) m Fining means (FM) sueh as v a <::: u m c p s a r e o t d n f in i x y h v b like z g w for making low velocity impacts art the panel solenoid> drives > t h e p e n p 1 o 11 e r i n a c c o r d a n c e w i t h t h e u p iAnd down commands received from a digitaX kna1og converter (DAC) connected to a computer PC 386 „ A stepper motor (SM) connected to the computer and rBCBiving commands therefrom drives the movable arm of the device to any desired direction in the XY axis of the flat panel- Impacts produced duns to the up and down movements of the pen p 1 otter are sensed by sensing means consisting of signal conditioners (SO) and analog digital conditioners ADC. The processed Big n a 1 s a r e f ed to the c om pu t e r (PC 3S6 ) f o r B t o r ag e .. A cathod ray osci11ograph (CRD) is connected to the sensing and processing means to d ispIay the signa1s during testing-Anoma 1 ies in the signa 1 s received are uti I ised to 1 ocat$ good and bad area55 in the panels. It will be obvious to persons ©ki1 led in the art that numerous modification and variations are possible without d e p a r t i n g f r o m t h e b a s i c i n v e n t i v e c o n c e p t. s - A11 & u c h mod i f ication 5 and variations are to be considered w i th in the scope of the present invention P the nature of which is described herein above and c1aimed in the appended claims. WE CLAIM : 1. A portable device for automatic non destructive testing of panels comprising a flat bed plotter consisting of a drivable pen plotter provided with force guage, control means commanding up and down movements of the said pen plotter, drive means to drive the said plotter in the X-Y axis of the said panel, fixing means to fix the said plotter at any desired location on the said panel, the said plotter having connected thereto signal sensing means, signal processing means, signal storage and signal display means to sense, process store and display the signals received therefrom. 2. The portable device as claimed in claim 1, wherein the force gauge of the pen plotter is piezo electric force gauge. 3. The portable device as claimed in claim 2, wherein the piezo electric force gauge is a transducer. 4. The portable device as claimed in any one of the preceding claims, wherein the said pen plotter is provided with a solenoid for imparting up and down movement thereto. 5. The portable device as claimed in claims 1 to 4, wherein the pen plotter is mounted on a movable arm and the drive means is a stepper motor connected to a computer. 6. The portable device as claimed in any one of the preceding claims, wherein the fixing means are vacuum cups located on a frame member. 7. The portable device as claimed in any one of the preceding claims, wherein the signal sensing means and signal processing means are signal conditioners and analog digital converters connected to a computer. 8. The portable device as claimed in any one of the preceding claims, wherein the signal storage means is a computer and the signal display means is a cathode ray oscillograph. 9. The portable device as claimed in any one of the preceding claims, wherein the control means commanding up and down movement of the pen plotter is a digital analog converter connected to a computer. 10. A portable device for automatic non destructive testing of panels, substantially as hereinabove described and illustrated with reference to the accompanying drawing.

Documents:

2237-mas-1996-claims filed.pdf

2237-mas-1996-claims granted.pdf

2237-mas-1996-correspondnece-others.pdf

2237-mas-1996-correspondnece-po.pdf

2237-mas-1996-description(complete)filed.pdf

2237-mas-1996-description(complete)granted.pdf

2237-mas-1996-drawings.pdf

2237-mas-1996-form 1.pdf

2237-mas-1996-form 26.pdf

2237-mas-1996-form 4.pdf