TABLE OF CONTENTS The study of dynamic tests on materials constitutes a vast and complex research field, which has very diverse applications: defense, transportation, civil engineering, machining, forming.
Properly speaking, dynamic tests assume inertia forces and thus propagation phenomena, which have an influence on the behavior of the test piece: this behavior then results from local effects at the scale of microstructure and from global effects at the scale of the mechanical structure; it is always tricky to dissociate local from structural effects, owing to the complexity of their interactions.
Depending on whether the loading is sustained generally harmonic or more seldom pseudo-random or transient, the tests are denoted as stationary or short transient, usually performed by shock or impact loadings; loadings achieved in very short times (0.1 ms 1 s) then produce strain rates from 1 s ?1 to 10 7 s ?1. This chapter is devoted to transient cases.
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Taking into account inertia effects in transient cases is usually difficult, only because the entire kinematics of the test piece are not experimentally accessible. At best, kinematics histories are available at one or two, sometimes a few points. Generally the test must be analyzed by inverse methods assuming the form of constitutive equations and with the help of numerical tools. Nevertheless, there exist experimental techniques, which, beyond the time to create an equilibrium, ensure a quasi-static state of the test piece. This allows us, as a first step at least, to get rid...
