Utilizing Elastic Deflection

Elastic deflection can be used both to apply the load and to sense the response of the sliding body in a friction-measuring device. This was the principle employed by Bowden and Leben in their now classical research of the late 1930 s [4]. Today their apparatus is only of historic interest. A modern application of the elastic deflection principle is exemplified by the dual cantilever beam, such as is described by Bayer al. [5] and illustrated in Fig. 7-6. Two independently acting elastic 

Buckley, Swikert and Johnson [9] applied the principle of lever loading and elastic deflection to the measurement of friction in high vacuum (13.3 uPa, 10 torr). Their apparatus is illustrated diagram-matically in Fig. 7-10. The rotating specimen and its drive shaft are 

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Indentation force measurements utilize the indentation part of a force-displacement curve (Fig. 4.19). In the case of a non-compliant sample surface, the SFM tip does not indent the sample and hence the deflection vs. piezo position curve in the contact region has a slope of 1.0. For compliant samples, the slope is <1.0 and can be used to obtain the elastic modulus of the sample by fitting the measured... 

Deflection temperature under load (DTUL) measures the temperature at which a specimen of a certain geometry deflects a fixed amount under a very specific set of conditions. However, it is often used in material selection as a measure of the maximum continuous use temperature for that material. The development of dynamic mechanical analysis (DMA) has shown that traditional DTUL test results often give a false measure of the thermal performance of polymeric materials. By measuring the elastic modulus versus temperature by DMA the thermal profile of any polymer can be obtained and a more realistic assessment of the elevated temperature performance can be obtained. New techniques were also presented for testing adhesive bond strength tests for piping systems. The technique developed utilized lap-shear plaques to predia performance in the pipe joint systems. Results indicate extreme sensitivity to minor variations in preparation. 

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