Abstract:

A novel methodology was proposed using inertial effects at high strain rates to take advantages
of full-field measurements, especially the ability to measure the heterogeneous deformation. The acceleration
fields and the dynamic strain fields were acquired on the specimen surface under impact load by ultra-high
speed full-field measurements. Then, full-field data were processed by the virtual fields method to identify
material constitutive parameters. Both the numerical simulation and experimental tests validated the feasibility of
this methodology. The results show that the application of inertial effects for high strain rate testing can simplify
the experimental set-ups. For instance, the input and output bars in Hopkinson bar tests are not be required
anymore because of no need of any impact force measurement. Moreover, the design space for high strain rate
testing can be enlarged to the specimens with complex shape or soft texture.

Key words:  impact tests, full-field measurements, high strain rates, the virtual fields method, grid methods, composites