Viscoelastic-Viscoplastic Modelling of the Scratch Response of PMMA

<table>Comparison of experimental results (<svg height="16.3125" id="M167" style="vertical-align:-3.276pt" version="1.1" viewbox="0 0 47.212502 16.3125" width="47.212502" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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</svg>) and numerical results (elastic-viscoplastic and viscoelastic-viscoplastic) for <svg height="15.4" id="M168" style="vertical-align:-3.3907pt" version="1.1" viewbox="0 0 53.037498 15.4" width="53.037498" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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<g transform="matrix(.012,-0,0,-.012,10.637,15.187)"><path d="M495 86q-46 -47 -87 -72.5t-63 -25.5q-43 0 -16 107l49 210q7 34 8 50.5t-3 21t-13 4.5q-35 0 -109.5 -72.5t-115.5 -140.5q-21 -75 -38 -159q-50 -10 -76 -21l-6 8l84 340q8 35 -4 35q-17 0 -67 -46l-15 26q44 44 85.5 70.5t64.5 26.5q35 0 10 -103l-24 -98h2
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</svg> mN. The data denoted by <svg height="11.375" id="M169" style="vertical-align:-0.1638pt" version="1.1" viewbox="0 0 58.637501 11.375" width="58.637501" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,11.112)"><path d="M609 650l-19 -162l-30 -2q2 69 -14 94q-9 18 -28.5 26t-74.5 8h-88q-30 0 -37 -6.5t-12 -36.5l-41 -212h103q48 0 69 5.5t32 19t26 50.5h29l-40 -198h-30q2 58 -11.5 70.5t-85.5 12.5h-99l-30 -167q-17 -87 3 -101q18 -15 111 -15q59 0 89 7t54 27q8 7 15.5 16t16 21.5
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</svg> GPa (resp., <svg height="11.375" id="M170" style="vertical-align:-0.1638pt" version="1.1" viewbox="0 0 58.637501 11.375" width="58.637501" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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</svg> GPa) are those calculated with the elastic-viscoplastic model in using a Young modulus of 2.75 GPa (resp., 3.25 GPa). The data denoted VEVP corresponds to the viscoelastic-viscoplastic model.</table>

Advances in Materials Science and Engineering

Viscoelastic-Viscoplastic Modelling of the Scratch Response of PMMA

Figure 17