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"ABSTRAKFaktor 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."

"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."

"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."

"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."

"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.

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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."