Analisa Pengaruh Panjang Adhesive Layer Terhadap Respon Tegangan-Regangan Sambungan Tubular Lap Adhesive Joint Pada Laju Regangan Tinggi Menggunakan Simulasi Explicit Dynamic

Ridho, Mahalli (2020) Analisa Pengaruh Panjang Adhesive Layer Terhadap Respon Tegangan-Regangan Sambungan Tubular Lap Adhesive Joint Pada Laju Regangan Tinggi Menggunakan Simulasi Explicit Dynamic. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Dalam memproduksi sebuah kendaraan, produsen otomotif harus mengutamakan keselamatan penumpang. Pada rangka otomotif, terdapat berbagai jenis sambungan yang dirancang untuk menopang struktur kendaraan. Tetapi hingga saat ini, jenis sambungan yang digunakan masih jenis sambungan konvensional. Apabila terjadi benturan keras seperti tabrakan, maka jenis sambungan konvensional tidak bisa berperan banyak dalam menyelamatkan penumpang, karena pada jenis sambungan konvensional terdapat konsentrasi tegangan. Namun konsentrasi tegangan tersebut dapat diredam oleh material yang memiliki sifat bisa meredam energi dengan baik, salah satunya adalah adhesive.
Sifat mekanik adhesive joint ditentukan oleh properties dari base material, bulk adhesive dan geometri sambungan. Variasi panjang overlap pada sambungan adhesive jenis tubular lap joint akan mempengaruhi sifat mekaniknya Penelitian ini mempelajari tentang pengaruh variasi panjang overlap terhadap respon tegangan-regangan sambungan hollow tubular adhesive lap joint pada laju regangan tinggi. Diamati juga pengaruhnya terhadap kurva tegangan-regangan sambungan yang diperoleh dari simulasi numerik uji Split Hopkinson Pressure Bar (SHPB) menggunakan ANSYS explicit dynamics.
Uji SHPB dan model finite element dilakukan menggunakan spesimen adhesive tubular lap joint dengan base
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material pipa aluminium 6061. Pipa besar memiliki diameter dalam 18,7 milimeter sedangkan pipa kecil memiliki diameter luar 17 milimeter dan panjang total 100 milimeter. Variasi panjang overlap yang digunakan pada eksperimen ini adalah 10 mm; 15 mm; 20 mm; dan 25 mm. Hasil pengujian SHPB digunakan untuk validasi model elemen hingga di ANSYS dengan cara membandingkan respon tegangan regangan keduanya pada laju deformasi atau strain rate yang sama.
Pengujian dan simulasi dilakukan pada laju regangan yang sama orde sepuluh. Hasil yang didapatkan dari pengujian menunjukkan bahwa sambungan adhesive hollow tubular lap joint berdeformasi elastis selama periode pembebanan, dimana spesimen mengalami proses kompresi dan proses ekspansi. Pada kurva tegangan regangan sambungan mengalami kenaikan tegangan yang proporsional dengan bertambahnya regangan hingga titik tertentu, lalu mengalami penurunan tegangan hingga kembali ke titik 0 Pa. Dari hasil pengujian baik eksperimen maupun simulasi menunjukkan secara kualitatif bahwa semakin panjang overlap sambungan maka tegangan akan meningkat secara non-linear, sehingga nilai tegangan terbesar didapatkan pada sambungan dengan panjang overlap 25 mm. Hasil penelitian ini akan sangat membantu produsen manufaktur khususnya otomotif dalam mempertimbangkan panjang overlap pada sambungan adhesive hollow tubular lap joint jika diaplikasikan pada daerah sambungan yang mengalami beban tumbukan.
Kata kunci: overlap, adhesive hollow tubular lap joint, tegangan kombinasi, peel stress, explicit dynamics, Split Hopkinson Pressure Bar.
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In producing a vehicle, automotive manufacturers must prioritize passenger safety. In automotive frames, there are various types of joints designed to support the vehicle structure. But at present, the type of joints used is still the conventional type. In the event of a hard collision, the conventional connection type is not safe for passengers, as the conventional connection type is related to tension regulation. However, this stress concentration can be dampened by materials that have good energy absorption properties such as adhesive.
The mechanical properties of adhesive joints are determined by the properties of the base material, bulk adhesive, and the connection geometry. Variations in the overlap length of the tubular joint adhesive type will affect of variations in overlap lengths on the stress-strain response of hollow tubular adhesive lap joints at high strain rates. The effect of the joint stress-strain curve was also observed, which was obtained from the numerical simulation of the Split Hopkinson Pressure Bar (SHPB) test using ANSYS explicit dynamics.
The SHPB test and finite element model is using a specimen of adhesive tubular lap joint with aluminum 6061 as the base material. The large pipe has an inner diameter of 18,7 mm, a small pipe has an outer diameter of 17 mm, and the total length of the specimen is 100 mm. the variation of the overlap length used in this experiment is 10 mm; 15 mm; 20 mm; and 25 mm. The SHPB
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results were used to validate the finite element model in ANSYS by comparing the response of stress-strain at the same deformation rate or strain rate.
Experiment and simulations are carried out at the same orde 101 strain rate. The lap hollow tubular adhesive deforms elastically during the loading period, during which the specimen enhances the compression and expansion processes. In the joint stress-strain curve, there is a proportional increase in stress with the increase in strain up to a certain point, then the stress decreases until returns to point 0 Pa. From the test results, both experiments and simulations show qualitatively that the longer the overlap joints, the non-linear tension increases, so that the greatest stress value is obtained at joints with an overlap of 25 mm. The results of this study will greatly assist manufacturing manufacturers, especially in automotive considerations in the lap joint tubular adhesive joints if applied to the junction areas that experience impact loads.
Keywords: overlap, adhesive hollow tubular lap joint, combination stress, peel stress, explicit dynamics, Split Hopkinson Pressure Bar.

Item Type: Thesis (Other)
Uncontrolled Keywords: overlap, adhesive hollow tubular lap joint, tegangan kombinasi, peel stress, explicit dynamics, Split Hopkinson Pressure Bar, combination stress.
Subjects: T Technology > TJ Mechanical engineering and machinery
Divisions: Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User: Mahalli Ridho
Date Deposited: 23 Aug 2020 03:02
Last Modified: 23 Jun 2023 07:11
URI: http://repository.its.ac.id/id/eprint/80188

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