Studi Eksperimental Pengaruh Laju Regangan Terhadap Respon Viskoelastis Senar Komposit Alami dan Sintetis Pada Raket Tenis

Nurdin, Muhammad Amin (2026) Studi Eksperimental Pengaruh Laju Regangan Terhadap Respon Viskoelastis Senar Komposit Alami dan Sintetis Pada Raket Tenis. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Senar raket tenis berperan penting dalam menentukan performa permainan, khususnya dalam hal kontrol, daya pantul, dan kenyamanan saat kontak dengan bola. Karakteristik viskoelastis dari senar menjadi krusial karena sifat ini mencerminkan kemampuan material dalam merespons gaya secara waktu-tergantung, terutama di bawah pembebanan dinamis saat bermain. Namun, pendekatan eksperimental konvensional seperti uji creep tidak selalu praktis karena keterbatasan alat uji dalam menjaga beban konstan. Penelitian ini bertujuan untuk mengkaji karakter viskoelastis senar raket tenis berbahan komposit alami dengan natural gut tipe Babolat VS Touch dan senar sintetis dengan synthetic gut tipe Wilson Synthetic Gut Power melalui pendekatan eksperimental menggunakan uji tarik dengan variasi laju regangan (strain rate). Uji dilakukan dengan metode tarik normal dengan strain rate tinggi (260 mm/min), uji ini bertujuan untuk mengevaluasi sifat mekanik dasar dari senar raket meliputi tegangan maksimum (tensile strength), tegangan luluh (yield strength), modulus elastisitas (Young’s modulus), dan profil kurva tegangan-regangan (stress-strain). Kemudian uji tarik lambat dengan strain rate rendah (0,0026 mm/min), uji ini bertujuan untuk mengevaluasi parameter viskoelastisitas, yaitu berupa ε∞ (strain maksimum jangka panjang) dan τ (waktu retardasi) melalui data strain–time yang dianalisis menggunakan model matematis Kelvin–Voigt. Hasil uji tarik normal menunjukkan bahwa senar natural gut mengalami deformasi nonlinier dengan indikasi respons viskoelastis awal, ditandai oleh peningkatan tegangan yang gradual dan kecenderungan penurunan tegangan pada regangan tinggi, sedangkan senar sintetis menunjukkan perilaku mekanik elastik–plastik yang lebih linear tanpa indikasi viskoelastis yang signifikan pada kondisi pembebanan cepat. Sebaliknya, pada uji tarik lambat, senar sintetis menunjukkan respons viskoelastik yang lebih dominan, ditunjukkan oleh nilai strain maksimum jangka panjang dan waktu retardasi yang lebih besar dibandingkan senar natural gut. Hasil penelitian ini menunjukkan bahwa karakter viskoelastis senar raket tenis sangat dipengaruhi oleh laju regangan. Senar natural gut cenderung menunjukkan respons viskoelastis yang lebih nyata pada pembebanan cepat, sedangkan senar sintetis menunjukkan dominasi perilaku viskoelastis pada pembebanan lambat. Studi ini menegaskan pentingnya mempertimbangkan efek laju regangan dalam evaluasi material senar raket tenis, serta menunjukkan bahwa uji tarik lambat dapat digunakan sebagai pendekatan alternatif yang efisien untuk mengkaji karakter viskoelastisitas material tanpa harus bergantung sepenuhnya pada uji creep konvensional. Kata kunci: Model Kelvin–Voigt, Senar Natural Gut, Senar Sintetis, Strain Rate, Uji Tarik, Viskoelastis.
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Tennis racket strings play a crucial role in determining performance, particularly in terms of control, rebound power, and comfort during ball contact. The viscoelastic characteristics of strings are essential, as they reflect the material's ability to respond to forces over time, especially under dynamic loading during play. However, conventional experimental approaches such as creep testing are not always practical due to limitations in test equipment for maintaining a constant load. This study aims to investigate the viscoelastic behavior of tennis racket strings made from natural composites, specifically natural gut (Babolat VS Touch) and synthetic strings (Wilson Synthetic Gut Power), through experimental approaches using tensile testing at varying strain rates. Two methods were used: normal tensile testing at a high strain rate (260 mm/min), to evaluate the basic mechanical properties of the strings, including tensile strength, yield strength, Young’s modulus, and stress–strain profiles and slow tensile testing at a low strain rate (0.0026 mm/min), to evaluate viscoelastic parameters such as ε∞ (long-term maximum strain) and τ (retardation time) using strain–time data analyzed with the the mathematical model. The normal tensile test was employed to evaluate the fundamental mechanical properties of the racket strings, including tensile strength, yield strength, Young’s modulus, and the characteristics of the stress–strain curve. Meanwhile, the slow tensile test was used to evaluate viscoelastic parameters, namely the long-term maximum strain (ε∞) and the retardation time (τ), derived from strain–time data analyzed using the Kelvin–Voigt viscoelastic model. The results of the normal tensile test indicate that natural gut strings exhibit nonlinear deformation with early viscoelastic-like responses, characterized by a gradual increase in stress and a tendency for stress reduction at higher strain levels. In contrast, synthetic strings display a more linear elastic–plastic mechanical behavior without significant viscoelastic indications under rapid loading conditions. Conversely, under slow tensile testing, synthetic strings demonstrate a more dominant viscoelastic response, as indicated by higher values of long-term maximum strain and retardation time compared to natural gut strings. Overall, the results demonstrate that the viscoelastic behavior of tennis racket strings is strongly influenced by the applied strain rate. Natural gut strings tend to exhibit more pronounced viscoelastic responses under rapid loading, whereas synthetic strings show dominant viscoelastic behavior under slow loading conditions. This study highlights the importance of considering strain-rate effects in the evaluation of tennis racket string materials and demonstrates that slow tensile testing can serve as an efficient alternative approach for characterizing viscoelastic properties without relying solely on conventional creep testing. Keywords: Kelvin–Voigt Model, Natural Gut Strings, Synthetic Strings, Strain Rate, Tensile Test, Viscoelasticity.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Model Kelvin–Voigt, Senar Natural Gut, Senar Sintetis, Strain Rate, Uji Tarik, Viskoelastis. Kelvin–Voigt Model, Natural Gut Strings, Synthetic Strings, Strain Rate, Tensile Test, Viscoelasticity.
Subjects:	Q Science Q Science > Q Science (General) Q Science > Q Science (General) > Q180.55.M38 Mathematical models
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Muhammad Amin Nurdin
Date Deposited:	04 Feb 2026 03:54
Last Modified:	04 Feb 2026 03:54
URI:	http://repository.its.ac.id/id/eprint/132035

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