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Abstrak :
Dalam pengembangan produk otomotif selain peningkatan performa dan efisiensi bahan bakar, fitur keselamatan tetap menjadi faktor utama yang perlu dipenuhi untuk menjamin keselamatan penumpang. Metode pengujian Crashworthiness dilakukan untuk mengevaluasi desain struktur kendaraan yang boleh berdeformasi, berdasarkan parameter energi absorpsi tumbukan dan efisiensi gaya tumbukan-nya. Mayoritas kecelakaan lalu- lintas melibatkan tabrakan pada arah depan kendaraan, membuat struktur bumper kendaraan menjadi bagian penting, serta didesain spesifik untuk berdeformasi sehingga dapat menyerap energi kinetik tumbukan secara efektif dan mengurangi penyebaran energi yang dapat mempengaruhi pengguna dan struktur lain kendaraan. Variasi geometri struktur dikembangkan dengan menambahkan crush initiator sehingga mempengaruhi karakteristik struktur dalam menyerap energi kinetik. Tujuan dari penelitian ini untuk mengetahui performa crashworthiness dari desain struktur Tabung berdinding tipis dengan penambahan crush initiator pada sudut struktur tabung. Pengujian pembebanan kuasi statik dengan metode ekperimental dan numerikal sementara pembebanan dinamik dilakukan dengan metode numerikal menggunakan software Ansys-LS Dyna. Hubungan variasi dimensi dan jarak crush initiator diteliti untuk mengetahui pengaruhnya terhadap struktur sehingga didapat desain dengan performa crashworthiness terbaik. Hasilnya pengujian menunjukan pengaruh signifikan dari pemberian crush initiator pada tabung berdinding tipis terhadap performa crashworthiness untuk menurunkan gaya tumbukan awal, serta hasil antara eksperimen dan numerik menunjukan pola dan karakteristik yang menyerupai. ......The developments of vehicle, apart from improving engine performance and fuel efficiency, safety features remain the major factor that needs to be met to ensure safety. The Crashworthiness test method is carried out to evaluate the design of a deformable vehicle structure, based on the parameters of the absorption energy and its crush force efficiency. The making the vehicle crashbox structure an important part that specifically designed to deformable, and absorp the kinetic energy of the collision effectively and reduce the spread of energy that can affect the occupant and other structures of the vehicle. Variations in geometry are developed by adding Crush-Initiator that affects the characteristics of the structure in absorbing energy. The purpose of this research is to determine the crashworthiness performance of thin-walled tube structure design with the addition of Crush Initiator at the corner of the tube structure known as V-Notch or Diamond notch. Quasi-static loading were conduct with experimental and numerical methods while dynamic loading is carried out by numerical method using Ansys-LS Dyna software. The relationship between dimension variations and crush initiator distance is investigated to determine its effect on the structure in order to obtain the design with the best crashworthiness performance. The results show significant effect of crush-initiator on the crashworthiness to reduce the initial impact force, and the experimental and numerical results show similar patterns and characteristics.

Abstrak :
ABSTRAK Faktor keselamatan atau crashworthiness adalah hal terpenting dalam merancang suatu kendaraan. Struktur rel depan yang terletak di zona benturan berguna untuk dapat menyerap energi saat terjadi tabrakan dari arah depan, dengan begitu energi yang tersalurkan ke dalam kabin penumpang akan lebih kecil dan diharapkan tidak membahayakan penumpang. Struktur berdinding tipis banyak digunakan dalam aplikasi crashworthiness karena mempunyai rasio kekuatan dan berat struktur yang tinggi, harganya relatif murah, dan mempunyai kemampuan menyerap energi yang baik. Pada penelitian ini, pengaruh struktur baja persegi bernodal stiffeners dengan variasi desain ketebalan, bentuk, dan posisi dari nodal akan diamati sehingga mendapatkan nilai kriteria crashworthiness berupa penyerapan energi spesifik SEA , gaya tumbukan puncak peak force , dan efisiensi gaya tumbukan CFE . Pemberian nodal diharapkan dapat meningkatkan SEA dan CFE, lalu menurunkan nilai peak force. Setelah itu, urutan kombinasi desain optimum akan diperoleh dengan metode Vikor. Spesimen uji dengan faktor desain berbeda akan dilakukan uji simulasi numerik dengan memodelkan pengujian beban impak menggunakan software PAM-Crash. Variasi desain bentuk nodal penuh memiliki pengaruh paling besar terhadap nilai kriteria crashworthiness terbaik. Spesimen 12 0.8 F 150 sebagai kombinasi desain optimum.

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ABSTRACT Vehicle safety or crashworthiness is the most important factor to design a vehicle. The function of frontal rails which is located on crumple zone is to absorb energy when collision happens, so that the energy occur on passenger cell is minimized and less dangerous. Thin walled structures generally used in many applications of crashworthiness because it has high strength and weight ratio, inexpensive, and have a good energy absorber ability. In this study, the effect of nodal stiffeners with varied thickness, shape, and nodal position is observed to get a crashworthiness criterias, namely is specific energy absorption SEA , peak crushing force peak force , and crush force efficiency CFE . Nodal installations hopefully can increase SEA and CFE, then decrease peak force. After that, optimum design combinations obtained from Vikor method. Specimen with a different design factors will be done by modelling a numerical simulation based on real experimental case use PAM Crash software. The design variations that have a full nodal show a significant effect to crashworthiness criteria. Specimen 12 0.8 F 150 is the optimum design combinations.

Abstrak :
Sejak tahun 2003 diperkenalkan sebuah teori baru mengenai torsi yang disebut dengan modèle couplè dimana dalam teori tersebut dinyatakan momen torsi yang bekerja pada balok-tipis penampang terbuka (open cross-section thin-walled) berhubungan erat dengan bending momen sehingga menyebabkan penyimpangan sudut torsi dan shear center mengalami displacement searah sumbu horisontal. Teori ini membantah teori klasik VZ. Vlasov yang menyatakan tidak ada displacement pada shear center. Teori modèle couplè ini masih dikembangkan hingga tahun 2012 dengan pembuktian secara eksperimental dan numerik. Hasil pembuktian itu ternyata mendukung teori modèle couplè. Dari studi pustaka dan penelitian pendahuluan didapati beberapa kekurangan dalam prosedur eksperimental. Berdasarkan hal tersebut, maka dilakukan penelitian kembali dengan memperbaiki prosedur eksperimen sekaligus ingin membuktikan apakah hasil eksperimental sesuai dengan teori Vlasov atau teori modèle couplè. Analisis penelitian ini dilakukan dengan membandingkan hasil uji eksperimental, pemodelan numerik menggunakan software, prosedur analisis teori Vlasov untuk balok-tipis, teori modèle couplè dan teori torsi yang umum. Hasil penelitian ini memperlihatkan sudut torsi dan shear center analisis numerik sesuai dengan teori Vlasov sedangkan hasil uji eksperimental masih sama dengan hasil eksperimental terdahulu yang mendukung teori modèle couplè. Walau hasil uji eksperimental ini mendukung teori modèle couplè, bukan berarti teorema modèle couplè telah terbukti. Untuk itu disampaikan pula saran-saran perbaikan yang perlu dilakukan jika eksperimen serupa akan dilakukan kembali. ...... Since 2003 introduced a new theory called the torque modèle couple where the theory expressed in torsion moment acting on the open cross-section thin-walled are closely related to the bending moment causing deviation angle of torsion and shear center experienced displacement in the direction of the horizontal axis. This theory denies the classical theory VZ. Vlasov stating there is no displacement of the shear center. Couple modèle theory is still being developed by 2012 with evidence experimentally and numerically. The results turned out to support the theory of proof modèle couple. From the literature study and preliminary research found several deficiencies in the experimental procedures. Based on this, the research conducted again by correcting the experimental procedure at the same time trying to prove whether the experimental results according to Vlasov theory or theories modèle couple. The analysis is done by comparing the test results of experimental, numerical modeling using the software, the analysis procedure Vlasov theory for thinwalled, modèle couple theory and general theory of torque. The results of this study show the torque angle and shear center in accordance with the numerical analysis of Vlasov theory while the experimental test results are still the same as previous experimental results that support the theory modèle couple. Although these experimental results support the theory test modèle couple, is not mean theorem has been proved. For it is also presented suggestions for improvement that need to be done if similar experiments will be performed again.

Abstrak :
ABSTRAK
Teknologi transportasi zaman sekarang khususnya mobil membutuhkan rancangan yang mengutamakan faktor keamanan, keselamatan serta perlindungan terhadap kompartemen penumpang yang dikenal dengan fenomena crashworthiness. Uji simulasi mengenai pengaruh penambahan polyurethane foam dengan menggunakan variasi crush initiator akan menjadi fokus penelitian dengan penyederhanaan pengujian crashworthiness menjadi pembebanan impak aksial. Tujuan utamanya adalah mengetahui pengaruh penambahan polyurethane foam dan crush initiator sehingga mampu meningkatkan penyerapan energi dan mengurangi gaya tumbukan puncak saat terjadi tabrakan. Hasil akhir yang diperoleh dari penelitian ini adalah penyerapan energi yang meningkat 6 hingga 20.23 dan minimalisasi gaya tumbukan puncak mencapai 47 saat terjadi tabrakan.

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ABSTRACT
Transportation technology in current day rsquo s, especially cars need a design that prioritizes security, safety and protection against passenger compartments known as crashworthiness phenomena. The simulation test of the effect of adding polyurethane foam by using a variation of the crush initiator will be the focus of the research with the simplification of crashworthiness testing into axial impact loading. The main purpose is to know the effect of adding polyurethane foam and crush initiator so as to increase energy absorption and reduce peak impact force during collision. The end of the result obtained from this research is the absorption of energy that increased 6 to 20.23 and minimization the peak crushing force reached 47 when the collision occured.

Abstrak :
Berdasarkan data dari Korlantas Polri yang dipublikasikan Kementerian Perhubungan, angka kecelakaan lalu lintas di Indonesia mencapai 103.645 kasus pada tahun 2021. Berdasarkan jenis kendaraan, keterlibatan kasus kecelakaan lalu lintas yang paling tinggi adalah sepeda motor dengan persentase 73%. Helm sebagai proteksi penumpang memiliki peran penting saat kecelakaan. Penelitian yang sudah dilakukan pada helm sebelumnya adalah pada lapisan dalam helm memakai honeycomb aluminium sebagai pengganti EPS . Kemudian pernah dilakukan juga penggunaan metal foam aluminum untuk menggantikan cangkang ABS . Lalu terakhir penggantian EPS dengan honeycomb aluminium dengan menambahkan kriteria kinematik and biomekanikal pada cedera kepala . Pada penelitian ini penulis mensimulasi impak pada helm honeycomb menggunakan ANSYS LS-DYNA dan memasukan variabel crush initiator pada honeycomb dan membandingkannya dengan helm EPS dan helm honeycomb tanpa crush initiator. Hasilnya helm honeycomb secara umum lebih baik dibandingkan dengan helm EPS terutama dengan ketebalan helm tipis (25 mm). Penambahan crush initiator hanya sedikit berpengaruh menaikkan performa crashworthiness sebesar 2-3% pada indikator g-force dan HIC. ......Based on data from the Korlantas Polri published by the Ministry of Transportation, the number of traffic accidents in Indonesia reaching to 103,645 cases in 2021. Based on the type of vehicle, the highest involvement in traffic accident cases is motorbikes with a percentage of 73%. Helmet as passenger protection has an important role during an accident. Research that has been done on helmets previously such as on the inner layer of the helmet using aluminum honeycomb as a substitute for EPS . Other than that, the use of aluminum metal foam was also carried out to replace the ABS shell . Then the last is the replacement of EPS with aluminum honeycomb by adding kinematic and biomechanical criteria for head injuries . In this study, the author simulate the impact of honeycomb helmet with ANSYS LS-DYNA and include a variable of crush initiator on the honeycomb and compares it with the EPS helmet and Honeycomb helmet without crush initiator. The result is honeycomb helmets are generally better than EPS helmets, especially helmet with thin thicknesses (25 mm). The addition of a crush initiator has a little effect on increasing the crashworthiness performance ranging by 2-3% in g-force and HIC indicator.

Abstrak :
This book presents a collection of chapters on the current problems of the theory of dynamical processes in generalized continua and structures, and has been compiled to commemorate the 70th birthday of Prof. Dmitry Indeitsev-a leading specialist in the field of dynamical processes in solids, fluids and structures. It discusses various applications related to Prof. Indeitsevs contributions, including various discrete and continuous dynamic models of structures and media, as well as a number of dynamical processes in generalized media.

Abstrak :
This book presents a theoretical approach that allows the analysis of structures with magnetorheological and electrorheological layers, and shows, with the help of examples, how the mechanical behaviour of thin-walled laminated structures can be influenced. It consists of six chapters: Chapter 1 presents a brief overview of derivation approaches for theories of thin-walled structures, modelling of composites and modelling of laminated and sandwich structures. Chapter 2 describes the equivalent single layer model for thin laminated cylindrical shells, including the special cases of plates and beams. In addition to the classical mechanical properties, it also considers the electrorheological and magnetorheological properties. Chapter 3 presents the elastic buckling of laminated beams, plates, and cylindrical shells, discussing various problems, such as the influence of the boundary conditions, external loading and magnetic fields. It also suggests different approximations for asymptotic methods. Chapter 4 focuses on the free vibrations of elastic laminated beams, plates and cylindrical shells, investigating the influence of the boundary conditions and other factors. Chapter 5 presents the latest results concerning vibration of laminated structures composed of smart materials and discusses in detail the influence of electric and magnetic fields on smart structures. These results provide insights into the optimal design of these structures. Lastly, Chapter 6 features a short appendix presenting asymptotic estimates and series.

Abstrak :
Ilmu umum crashworthiness, digambarkan dengan gaya tabrakan yang kecil untuk mengurangi deselerasi dan meminimalisir kecelakaan berat yang terjadi pada penumpang pada saat terjadi tabrakan. Untuk itu, diperlukan pengembangan struktur yang idealnya menyerap energi tinggi, dengan Initial Peak Force (IPF) yang rendah. Menurut jurnal yang telah diteliti, kemampuan penyerapan energi dapat dipengaruhi dari geometri struktur dan material yang digunakan. Struktur berdinding tipis berbentuk tabung lebih memiliki kemampuan Energy Absorption (EA), Specific Energy Absorption (SEA) yang lebih tinggi daripada struktur penampang bentuk lain. Masalah utama pada struktur tabung adalah nilai IPF yang sangat tinggi yang berpotensi menyebabkan kecelakaan berat. Oleh karena itu, optimalisasi struktur pada penelitian ini adalah dengan melakukan simulasi impact velocity test pada tabung terbuka dan tertutup untuk mengetahui geometri yang lebih baik dalam memenuhi kriteria crashworthiness. Setelah itu dilakukan simulasi pada struktur tabung terbuka tanpa crush initiator lubang, dengan tambahan crush initiator lubang berjumlah N-1, N-2, N-3, N-4 dan N-5. Tujuannya adalah untuk menurunkan nilai IPF, dan menentukan mode deformasi yang paling optimal beserta dengan kombinasi geometri struktur dan penggunaan material yang paling optimal, dengan tetap mempertahankan nilai EA, SEA dan Crush Force Efficiency (CFE). Metode simulasi dilanjutkan dengan validasi simulasi jurnal terkait. Hasil simulasi struktur diambil dengan metode pengambilan keputusan VIKOR dan didapatkan bahwa struktur tabung berdinding tipis material AA6061-T6 dengan penambahan crush initiator lubang sebanyak 3 level merupakan alternatif struktur yang paling optimal. ......The general science of crashworthiness, described by a small collision force to reduce deceleration and minimize serious accidents that occur to passengers in the event of a collision. For this reason, it is necessary to develop a structure that ideally absorbs high energy, with a low Initial Peak Force (IPF). According to the journal that has been researched, the ability to absorb energy can be influenced by the geometric structure and the materials used. The thin-walled tube structure has higher Energy Absorption (EA) and Specific Energy Absorption (SEA) capabilities than other cross-sectional structures. The main problem with the tube structure is the very high IPF value which causes serious accidents. Therefore, the optimization of the structure in this study is to perform a simulation of the impact velocity test on an open and closed tube to find out a better geometry in meeting the crashworthiness criteria. After that, simulations were carried out on an open tube structure without a hole crush initiator, with also additional crush initiators opening holes N-1, N-2, N-3, N-4 and N-5. The goal is to reduce the IPF value, and determine the most optimal deformation mode along with the most optimal combination of structural geometry and material use, while maintaining the EA, SEA and Crush Force Efficiency (CFE) values. The simulation method was followed by simulation validation journal. The results of the structural simulation were taken using the VIKOR decision-making method and it was found that the thin-walled tube structure of AA6061- T6 material with the addition of 3 levels of hole crush initiator is the most optimal alternative structure.

Abstrak :
This book presents simplified analytical methodologies for static and dynamic problems concerning various elastic thin plates in the bending state and the potential effects of dead loads on static and dynamic behaviors. The plates considered vary in terms of the plane (e.g. rectangular or circular plane), stiffness of bending, transverse shear and mass. The representative examples include void slabs, plates stiffened with beams, stepped thickness plates, cellular plates and floating plates, in addition to normal plates. The closed-form approximate solutions are presented in connection with a groundbreaking methodology that can easily accommodate discontinuous variations in stiffness and mass with continuous function as for a distribution. The closed-form solutions can be used to determine the size of structural members in the preliminary design stages, and to predict potential problems with building slabs intended for human beings practical use.