Home › Archive for Applications › Page 2

Applications

Vakuum loading on battery packs

Air inclu­sion or air pock­ets in mod­ern Li-bat­tery packs is a seri­ous and dan­ger­ous prob­lem. The isi-sys SE2 sen­sor is able to detect tiny and large defects such as air bub­bles, air pock­ets, cracks and oth­er with­in a sec­ond. The defects can be far below or near to the sur­face. An exam­ple of a bat­tery pack (test sam­ple from Uni­ver­si­ty of Munich, IWB) and the mea­sure­ment result is shown below.

Test set­up:

The test has been done by SE2 sen­sor in com­bi­na­tion with a glass vac­u­um cham­ber for a sim­ple man­u­al test. This is an eco­nom­ic solu­tion for spot NDT by man­u­al ser­vice. For auto­mat­ed series test in pro­duc­tion dif­fer­ent setups are required.

Test poce­dure:

The bat­tery packs are test­ed by small pres­sure dif­fer­ences of some mbar, which can be applied in sec­onds or below in small cham­bers. The sen­sor is mon­i­tor­ing the sur­face of the bat­tery pack while the pres­sure is changed, mea­sur­ing the dif­fer­en­tial defor­ma­tion of the sur­face. Due to the expan­sion of the air bub­bles and air pock­ets, the air inclu­sions can be locat­ed such as shown in the fol­low­ing images.

The first image shows the live view of the bat­tery pack from the sen­sor. The sec­ond shows the recon­truct­ed phase, which is cor­re­spond­ing to the local defor­ma­tion gradient.

battery pack3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

battery pack2

Gen­er­al­ly the required pres­sure dif­fer­ence depends on the defect depth, defect size an the mechan­i­cal stiff­ness of the test­ed struc­ture, but in gen­er­al the load is small due to the high sen­si­tiv­i­ty of the sen­sor detect­ing dif­fer­en­tial defor­ma­tions of the surface.

Operation mode analysis on a mobile phone during vibration alert

Nokia3

x

Ref­er­ence coor­di­nates and con­tour of the mobile phone.

 

 

 

x

 

This arti­cle describes the mea­sure­ment and analy­sis of the oper­a­tion deflec­tion shapes and rigid body vibra­tion motions of a mobile phone excit­ed by its vibra­tion alert. The mearure­ment is done, using a non con­tact, 3D, full-field, high speed stereo image cor­re­la­tion sys­tem in com­bi­na­tion with the new Vic-3D FFT mod­ule ana­lyzes the record­ed defor­ma­tion data in the fre­quen­cy domain by phase-sep­a­ra­tion method.

Nokia

The mea­sured defor­ma­tions and dis­place­ments dur­ing the vibra­tion alert are eval­u­at­ed against the ref­er­ence state for each stereo image pair. In this case the record­ing time cov­ers about 5,5 sec­onds with 1000 FPS cor­re­spond­ing to about 5500 sin­gle measurements.

The fol­low­ing fig­ure show the aver­age vibra­tion ampli­tude U.

 

Nokia2

Dynamic Compression of Metals

Dynamic compression

Study­ing the behav­ior of met­als dur­ing a high-speed dynam­ic com­pres­sion event has always been chal­leng­ing due to the com­plex test set up and fast data cap­ture rates required. Cur­rent­ly, very lit­tle lit­er­a­ture is avail­able regard­ing defor­ma­tion behav­ior at strain rates of  10 to 500s-1. Uti­liz­ing high-speed cam­eras, the Vic-3D HS sys­tem can be used to quan­ti­fy the sur­face dis­place­ments and strains in three dimen­sions over the entire field with great pre­ci­sion. Dig­i­tal Image Cor­re­la­tion (DIC) has gained wide­spread pop­u­lar­i­ty over recent years in such high-speed appli­ca­tions due to its high accu­ra­cy, flex­i­bil­i­ty and ease of use.

 

 

 

Dynamic compression2In this exam­ple, a 6mm diam­e­ter cylin­dri­cal spec­i­men was com­pressed at a strain rate of 50s-1. The Vic-3D HS sys­tem was used to cap­ture the  sur­face dis­place­ments and  strains on  the  spec­i­men dur­ing the event. A ran­dom speck­le pat­tern is applied to the spec­i­men that allows the analy­sis soft­ware to eas­i­ly track the defor­ma­tion to sub-pix­el accu­ra­cy. Although the high- speed cam­eras are capa­ble of much high­er cap­ture rates, for this test they were set to an appro­pri­ate frame rate of 14,400fps to max­i­mize spa­tial res­o­lu­tion while acquir­ing an ade­quate num­ber of images dur­ing the event. The cam­eras were post-trig­ger at a res­o­lu­tion of 1024 x 400 pix­els. After the event, the images are trans­ferred to the computer’s  hard  dri­ve, and  then  post-processed using Vic-3D analy­sis software.

Images cour­tesy of Amos Gilat & Jere­my Sei­dt at Ohio State University.

 

 

Contractions of a Muscle

Bio­me­chan­ic researchers were study­ing the con­trac­tions of a rat Tib­ialis Ante­ri­or mus­cle.  It was desir­able to quick­ly and accu­rate­ly quan­ti­fy the over­all move­ments, as well as local­ized variations.

Challenges

Because the exper­i­ments involved live tis­sues, con­ven­tion­al gauges were dif­fi­cult to apply and tend­ed to inter­fere with the motion under study.  It was impor­tant to cap­ture data quick­ly, and for as many points as pos­si­ble.  Mark­er track­ing had been used, but pro­vid­ed only gross aver­ages.  It was also time-con­sum­ing and tedious for the researchers to process this type of  information.

Solution

The Vic-3D sys­tem was used to rapid­ly cap­ture con­trac­tion data over the entire mus­cle sur­face.  Due to the system’s speed and sim­plic­i­ty, it was pos­si­ble to make numer­ous mea­sure­ments at pre­cise­ly timed inter­vals.  There was no inter­ac­tion with the spec­i­men, and no need to guess which areas would be of great­est interest.

The result­ing mea­sure­ments pro­vid­ed high spa­tial res­o­lu­tion and made it pos­si­ble to iden­ti­fy numer­ous areas where “bunch­ing” of the mus­cle tis­sue caused sig­nif­i­cant vari­a­tions in mus­cle con­trac­tion.  These areas had not been pre­vi­ous­ly iden­ti­fied with con­ven­tion­al meth­ods.  Final­ly, all cal­cu­la­tions were done auto­mat­i­cal­ly.  This saved con­sid­er­able time and avoid­ed the pos­si­bil­i­ty of human error in the data processing.

 

Deformation Measurement

Aerospace Application Example

aerospace_1_notitle-300x247Air­bus has built a rep­u­ta­tion for inno­v­a­tive air­craft, rec­og­nized around  the world for their safe­ty and effi­cien­cy. All of these attrib­ut­es are dri­ven by a top-notch test­ing pro­gram, whose inno­v­a­tive prac­tice are evi­denced by their use of the Vic-3D mea­sure­ment system.

One of the goals of the Air­bus test­ing pro­gram is to char­ac­ter­ize the struc­tur­al dam­age caused by col­li­sions between the air­craft and small pro­jec­tiles such as birds and oth­er ground based debris, and to ensure that the struc­tur­al integri­ty of the air­craft is maintained.

This type of event can be repro­duced by fir­ing a vari­ety of dif­fer­ent types of pro­jec­tile at a piece of air­craft struc­ture at a high veloc­i­ty. The results obtained can be used to com­pare with com­put­er mod­els of the struc­ture under impact loads, lead­ing to more high­ly opti­mized and safer designs.

 

aerospace_2_notitle-300x224Dr. Richard Bur­guete, exper­i­men­tal mechan­ics spe­cial­ist at Air­bus UK since 1997, explains the ben­e­fits of this approach as fol­lows: “The VIC-3D sys­tem allows us to be sure we have cap­tured all of the rel­e­vant data, some of which might have oth­er­wise been unobtainable.”

Vibration Analysis of a Brake Disc

Bremsen1 Bremsen2
 x
Auto­mo­biles are sub­ject to many forces using oper­a­tion. Vibra­tions from the engine or the road-sur­face trans­mit through the vehicle’s chas­sis and sus­pen­sion to the most essen­tial mechan­i­cal com­po­nent of the vehi­cle, the brake system.

Bremsen3

In this exam­ple, a 14” diam­e­ter brake disc from a heavy­du­ty truck was excit­ed using a small ham­mer to mea­sure the vibra­tion shapes of the rotor. The three-dimen­sion­al oper­a­tional deflec­tion shapes were eas­i­ly iden­ti­fied and mea­sured using the Vic-3D™ HS Vibra­tion Analy­sis Sys­tem. Ampli­tudes as small as 40 nanome­ters were mea­sured at a fre­quen­cy of approx­i­mate­ly 2,000 Hz.

 

Strain Measurement on a Gearwheel

Challenges

Assem­bled com­po­nents typ­i­cal­ly have com­plex inter­ac­tions with one anoth­er. Con­tact points can vary dur­ing oper­a­tional cycles due to part move­ment. This means that the loca­tions of peak strains can be hard to pre­dict, and they are often not sta­tion­ary. The move­ment of parts can also make it imprac­ti­cal to main­tain elec­tri­cal con­nec­tions with gauges. Even when they are sta­tion­ary and easy to locate, the high­est strains can be con­cen­trat­ed in very small areas or have high gra­di­ents. Peak val­ues may be lost to the aver­ag­ing effect pro­duced by gauges.

 

Solution

Vic-3D pro­vid­ed a means for mak­ing strain mea­sure­ments across the entire pro­file of the gear tooth. Because it pro­vides full-field mea­sure­ments, it was not nec­es­sary to choose a par­tic­u­lar point at which mea­sure­ments would be made. This allowed the peak strains to be clear­ly visu­al­ized and accu­rate­ly mea­sured at var­i­ous stages of the oper­a­tional cycle. Vic-3D also mea­sured dis­place­ment in three dimen­sions. This fea­ture allowed our cus­tomer to rec­og­nize and quan­ti­fy twist­ing of the gear tooth under load.

Exhaust pipe

Exhaust1The engi­neers at Cum­mins design and test their engines to with­stand real-world con­di­tions, rang­ing from mil­i­tary deploy­ments to heavy-duty indus­tri­al sites. Cum­mins engi­neers want to know exact­ly how their parts are deform­ing under the com­bi­na­tion of ther­mal and mechan­i­cal loads. This means they’ve got to per­form their tests with the engines run­ning – and hot.

Because of the com­plex strain fields pro­duced under these con­di­tions, con­ven­tion­al gauges can­not sat­is­fy Cum­mins’ require­ments. FEA sim­u­la­tions are also lim­it­ed, due to the uncer­tain bound­ary con­di­tions. With the Vic-3D sys­tem, Cum­mins engi­neers are able to obtain detailed three-dimen­sion­al strain mea­sure­ments. These mea­sure­ments are made under real load­ing con­di­tions while the engine is run­ning. In addi­tion, the Vic-3D sys­tem is easy to set up and can mea­sure both small parts and large assemblies.

 

 .….….….….….….….….….….….….….….….….….….….….….…..

exhaust2

Paul Gloeck­n­er, senior research engi­neer at Cum­mins, explains the use­ful­ness of the Vic-3D sys­tem as fol­lows: “This tool allows us to make mea­sure­ments that were pre­vi­ous­ly not pos­si­ble. It has also allowed us to con­sid­er­ably reduce the time required for these tests.”

Dynamic excitation on a spacecraft

Historic measurement from 2000

This exam­ple com­bines the Vibro­grafie Sys­tem with a Piezoshak­er Mod­ule for a non-destruc­tive inspec­tion. The heat shield with C‑Si‑C (car­bon fiber-sil­i­con com­pos­ite) of the prospec­tive recov­ery vehicle/ space­craft x38 was reviewed by Shearog­ra­phy.

Spacecraft6

For eas­i­er han­dling, the Piezoshak­er mod­ule is com­pressed on the sur­face of the object via a suc­tion base.
(a) Piezoshak­er mod­ule, (b) the heat shield of the space­craft X38 © Flight of the space­craft X38.

x

spacecraft2

The pic­ture shows the deter­mi­na­tion of times of the heat shield with the nat­ur­al fre­quen­cy (1400 Hz).

 x

spacecraft3

Local vibra­tion forms of defects at 10kHz and 18 kHz of the nose hood in the marked area of the image. Dur­ing the inspec­tions, two defects have been detect­ed in the upper area of the dog.

NDT on Wind Rotor Blades

First test NDT Mea­sure­ment by shearog­ra­phy on a wind tur­bine blade in 1996 by P. Mäck­el, L. Yang, G. Kupfer and A. Tiemich at Kas­sel Uni­ver­si­ty. The object is a spe­cial wind rotor blade of a sin­gle wing wind tur­bine ener­gy plant.

RotorBlade

Applied load­ing method: Load­ing by inter­nal pres­sure (the blade has been sealed). A man­u­al pump has been used to increase a pres­sure dif­fer­ence against the sur­round­ing. The fringe images show areas at dif­fer­ent loca­tions. The fringes are pro­por­tion­al to the out of plane defor­ma­tion gra­di­ents of the sur­face, which allows to iden­ti­fy inho­mo­ge­neous stiff­ness of the struc­ture: left — Delam­i­na­tion; right — Axi­al crack; cen­ter ‑Struc­tur­al change over (dif­fer­ent num­ber of glas­fiber layers).