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

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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.

 

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.

 

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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.”

Dynamic excitation on a spacecraft

Historic measurement from 2000

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

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

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

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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 at 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.

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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).

 

 

Dynamic loading on a yacht mast

The example shows an application of NDT on a 30m CFK yacht mast (lower left). The time average result of the SE1 measurement and dynamic loading by our piezo-shaker (lower right) is indicating a larger delimitation below the surface starting from a small visible crack. Usually small cracks are often seen on the surface, but not all are related to delamination, which needs any repair.

NDT Yacht   NDT Yacht2


SE1 with Piezoshaker for dynamic loading


Defect detected by Vibrography / dynamic loading