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.

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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

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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.

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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.

 

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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.”