and copper - respectively, 50 and b=1,7 mm, with width deviation no more, than ±0,05 mm. The choice of bigger width (and lengths) aluminum preparations was connected with considerably smaller durability of this material, in comparison with copper, - for providing a sufficient correctness of tests. Length of working part of aluminum samples equaled l0=28 mm, copper 20 mm. Thus, the speed of relative deformation of samples equaled 0 ( ) l l t Δ = ε& aluminum samples it was equal 0,357 min-1, copper – 0,5 min-1. Conditional stretching tension stress in samples was determined by a formula h b P ⋅ =σ with initial values h and b. Other parts of samples (ends) were used for fastening of samples in grabs of the test machine so that the rupture of a sample was carried out not in capture zone, and in its working zone. For this purpose the ends were bent before acceptance of double thickness, with placement of cardboard laying in a bend, and, then, the ends were pasted over with a paper adhesive tape. Before the placing of samples in the test machine on these ends tiny aluminum clips with the hinges, necessary for more exact axial loading of samples that it is difficult to provide at direct use of large rigid grabs of the test machine Were attached. At test samples fastened in test machine grabs through tiny clips. 2.3 . Results of quasistatic experiments In fig. 2 are provided received by means of the computer of the test machine the chart of "loading - lengthening" and "stress - deformation" for one sample from an aluminum foil, and on fig. 3 – for one of a copper foil. Fig. 2. Charts of stretching of an aluminum foil Fig. 3. Charts of stretching of a copper foil When processing initial areas of the charts "stress - deformation" (0 – 0,9) for aluminum and (0 – 9) for copper were excluded. The same was carried out when processing charts of all other samples. Stretching charts σ- ε aluminum and copper foils have an appearance typical for plastic materials: with an initial site of elasticity, viscoplasticity and destruction. On the chart for a copper foil before destruction small falling of conditional stress ((increase of true stress) before a direct prompt macrorupture of a sample – germination of the main crack, the events for an aluminum foil in time ~ 0,12 sec., and for copper 0,05 sec. is observed.
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