Appl. Sci. 2023 , 13 , 1389
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Figure 15. Dependence of the value of the deflection arrow on the displacement of the movable handle at the fastening lengths: ( a ) 3mm, ( b ) 4mm, (c ) 5mm. The correctness of determining the deflection arrow using the developed image analy- sis technique was checked by comparing measured sample shortening with the analytically determined value using the formula given in [16]: Δ l = l ⎛ ⎝ 1 − 2 1 − 2 δ l 2 ⎞ ⎠ (3) where: l —sample length Δ l —sample shortening δ —deflection arrow. Figure 16 shows a comparison of the measured and theoretically calculated shortening of the paper sample with a clamping length of 4 mm and 5 mm as a function of its deflection. A slight difference between the measured and calculated values may result from the adopted destruction model, which does not reflect all the phenomena occurring during the test, or the inaccuracy of determining the deflection arrow by imaging methods.
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14
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Deflection arrow, mm
Deflection arrow, mm
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Figure16. Comparison of the measured and theoretically calculated sample shortening during the test for clamping length of ( a ) 4mmand ( b ) 5mm.
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