Motion Measurement on Rear Swinging Fork

The video shows the appli­ca­tion of a stereo image cor­re­la­tion (phase syn­chro­nized) for a three-dimen­sion­al dis­place­ment mea­sure­ment or move­ment analy­sis (Vic-3D).

The used stereo cam­era sys­tem is based on two 5 Mpix­el cam­eras with a frame rate of 6Hz (at full res­o­lu­tion) in com­bi­na­tion with the isi-sys syn­chro­niza­tion and trig­ger device for stro­bo­scop­ic obser­va­tion of peri­od­ic events.


Four mea­sure­ment areas (hydraulic cylin­der — below, wheel hub — left, swingarm — mid­dle and lin­ear unit — right above) with speck­le pat­terns were mon­i­tored for the eval­u­a­tion. The vec­tor arrows rep­re­sent the cur­rent dis­place­ment state.


Vibration Analysis of a Brake Disc

Bremsen1 Bremsen2
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.


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.


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.




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.”