If one is testing a high elongation rubber or elastomer, the extensometer
will need sufficient vertical travel and high accuracy throughout the entire test.
In October 2011, one extensometer
was installed across the almost W-E striking fault (190[degrees]/80[degrees]) in the Roznava Fault Zone.
Said PSC's CTO and co-inventor and engineer Athanasios lliopoulos, "Our extensometer
can measure strain in a deforming specimen or structure while it is being stretched more than 20 times its initial length.
The evolution regularity of MS signals frequency during the surrounding rock mass deformation was carried out compared with the results of the multipoint extensometers
in the region of MS events concentration.
Compared with mechanical extensometer
, video extensometer
has obvious advantages in engineering applications.
For tensile tests conducted without extensometer
, the nominal strain rate, [[??].sub.nom], can be calculated by dividing the actuator displacement rate by the length of the specimen reduced section, under the (reasonable) assumption that, up to maximum force, plastic strain is homogeneously distributed along the entire reduced section of the specimen.
Unlike traditional extensometers
, where users have to know where to place the extensometer
prior to the test, the DIC software maps the entire specimen surface and records full-field information, allowing users to draw virtual extensometers
anywhere on the specimen after the test.
One of the main advantages over clip-on extensometer
methods says the company, is that the UVX-Flexi system avoids the problem of knife-edge slippage, where the knife-edges can potentially cut into a specimen and induce a failure point.
uses state-of-the-art equipment to perform this tensile test, including a Tinius Olsen tensile machine, a furnace carousel that can heat up to three samples simultaneously to temperatures as high as 1800 degrees Fahrenheit and a new extensometer
that boasts improved turnaround time, repeatability and curve accuracy, as well as capabilities to handle a broad range of sample types and sizes.
Figure 5(b) illustrates the compaction time series recorded by two closely spaced extensometers
at Clear Lake and one extensometer
at Johnson Space Center.
During the test the actual deformation was recorded by a rapid video extensometer
. This recording made it possible to evaluate the deformation of the sample based on the time and find the actual contraction of the sample.
The unit is capable of mixed transducer interfacing, including LVDT, DC Strain Extensometer
and Quadrature encoder-based position measurement devices.