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"The use of composite materials with continuous fibers in the aircraft and aerospace industries requires a thorough knowledge of behaviors of these laminate composites under various loading conditions. Indeed, the aim of this work is to simulate linear and nonlinear behavior of a symmetric laminated composite under three-point bending tests. The modelization used is based on an analytical approximation that has been recently developed for isotropic materials. This approximation is still valid for the studied quasi-isotropic laminated composite because it is symmetric with a specific layer sequence. The overall response of laminate composite is determined from the behavior of each ply outside of their orthotropic axis. Two methods are used to calculate the equivalent longitudinal Young-modulus of the laminate. The result shows that when the deflection of the specimens is less than 2.5 times the thickness, the difference between the experimental and analytical curves is about 1% for the average global stresses method, and about 7.5% for the apparent bending modulus method. For large deflections, the difference relative to the first method remains less than 11% and the second method is about 20%."

"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."

"Silika nanopartikel merupakan salah satu nanomaterial yang pemanfaatannya cukup luas karena beberapa kekhasan yang dimilikanya. Sintesis silika nanopartikel biasanya dibuat dari tetraetil ortosilikat (TEOS) namun karena harga yang cukup mahal digantikan dengan natrium silikat. Sintesis silika nanopartikel dari natrium silikat menggunakan kombinasi dari metode sol-gel dan metode hot injection dengan memvariasikan suhu selama sintesis nanosilika. Larutan amonia dan etanol menjadi pelarut yang diinjeksikan dengan natrium silikat. Nanosilika yang terbentuk kemudian diuji untuk mengetahui struktur kristal dan morfologinya menggunakan XRD dan SEM. Nanosilika yang dihasilkan memiliki struktur amorf dengan ukuran kristal 37.21 nm dan 32.34 nm pada suhu ruangan dan pada suhu 60ºC. Morfologi dari nanosilika yang terlihat berbentuk spherical tetapi bentuk yang dihasilkan tidak homogen. Silika nanopartikel yang dihasilkan kemudian dimodifikasi dengan mencampurkan asam stearat untuk memberikan sifat hidrofobik dengan variasi 1:5 dan 1:1. Aplikasi nanosilika hidrofobik dilakukan dengan dua cara yaitu spray dan dip coating. Dengan teknik dip coating dengan perbandingan 1:5 dan suhu reaksi untuk sintesis nanosilika pada 70ºC dihasilkan sudut kontak tertinggi yaitu sebesar 92º.

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Silica nanoparticles are one of the nanomaterials that the use quite extensively because of some of their unique characteristics. The synthesis of silica nanoparticles is usually made from tetraethyl orthosilicate (TEOS) but because the price is quite expensive it is replaced with sodium silicate. The synthesis of silica nanoparticles from sodium silicate uses a combination of the sol-gel method and the heat injection method by varying the temperature of the solvent. Ammonia and ethanol solutions are solvents that injected by sodium silicate. The resulting nanosilica has an amorphous structure with a crystal size of 37.21 nm and 32.34 nm at room temperature and 60ºC. The morphology of nanosilica is spherical but the resulting shape is not homogeneous. The resulting silica nanoparticles were modified by mixing stearic acid to give hydrophobic properties with variations of 1:5 and 1:1 between the nanosilica and steaeric acid. The application of hydrophobic nanosilica is carried out in two techniques, spray and dip coating. With the dip coating technique with a ratio of 1:5 and the reaction temperature at 70ºC is giving the highest contact angle produced at 92º.

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"This clearly written, self-contained volume studies the basic equations of kinetic theory in all of space. It contains up-to-date, state-of-the-art treatments of initial-value problems for the major kinetic equations, including the Boltzmann equation (from rarefied gas dynamics) and the Vlasov-Poisson/Vlasov-Maxwell systems (from plasma physics). This is the only existing book to treat Boltzmann-type problems and Vlasov-type problems together. Although these equations describe very different phenomena, they share the same streaming term. The author proves that solutions starting from a given configuration at an initial time exist for all future times by imposing appropriate hypotheses on the initial values in several important cases. He emphasizes those questions that a mathematician would ask first: Is there a solution to this problem? Is it unique? Can it be numerically approximated? The topics treated include the study of the Boltzmann collision operator, the study of the initial-value problem for the Boltzmann equation with "small" and "near equilibrium" data, global smooth solvability of the initial-value problem for the Vlasov-Poisson system with smooth initial data of unrestricted size, conditions under which the initial-value problem for the Vlasov-Maxwell system has global-in-time solutions (in both the smooth and weak senses), and more."

"ABSTRAKInteraksi yang kompleks antar lamina pada suatu laminat saat mengalami beban tarik menyebabkan perbedaan kuat tarik dan jenis kerusakan pada komposit laminat karbon/epoksi dengan susunan lamina yang berbeda. Untuk mengetahui pengaruh susunan lamina terhadap kuat tarik dan jenis kerusakan komposit laminat, 5 komposit laminat dibuat dengan metode hand lay up dengan susunan (0)5, (0/0/90)s, (0/45/-45/901/2)s, (0/45/-45/90)s dan (0/90/-45/45)s. Hasil uji tarik menunjukkan kuat tarik dari komposit laminat (0)5, (0/0/90)s, (0/45/-45/901/2)s, (0/45/-45/90)s dan (0/90/-45/45)s secara berturut-turut adalah ( 1988,97 ± 156,69 ) MPa, ( 1745,47 ± 19,53 ) MPa, ( 929,70 ± 32,79 ) MPa, ( 992,82 ± 26,63 ) MPa dan ( 941,86 ± 24,21 ) MPa. Hasil pengamatan dengan mikroskop optik pada bagian pinggir komposit laminat menunjukkan bahwa kerusakan yang terjadi pada setiap komposit laminat adalah delaminasi, retak mikro matriks dan perpatahan serat.

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ABSTRAKA complex interaction between lamina in laminate composites when receive an applied load causes different tensile strength values and types of damage on the carbon/epoxy laminate composites with different lamina stacking sequence. To know the effect of lamina stacking sequence on tensile strength value and the types of damage, five types of laminate composites were made by hand lay up method where the stacking sequence were (0)5, (0/0/90)s, (0/45/- 45/901/2)s, (0/45/-45/90)s dan (0/90/-45/45)s. The test results showed that the tensile strength value of the (0)5, (0/0/90)s, (0/45/-45/901/2)s, (0/45/-45/90)s and (0/90/-45/45)s laminates are ( 1988,97 ± 156,69 ) MPa, ( 1745,47 ± 19,53 ) MPa, ( 929,70 ± 32,79 ) MPa, ( 992,82 ± 26,63 ) MPa and ( 941,86 ± 24,21 ) MPa respectively. An observation with optical micrograph at the edge of laminate composites showed that the type of damages that occured on that laminates were delamination, matrix microcracking and fiber breakag"

"Pada praktek kedokteran gigi sehari-hari sering ditemukan kondisi pasien yang kehilangan gigi posterior dan ingin dirawat dengan gigi tiruan jembatan (GTJ), namun pasien tidak menginginkan banyak dilakukan pengasahan pada gigi tetangganya yang akan dijadikan penyangga (abutment). Sehingga dibuatkan alternatif GTJ dengan desain menggunakan bahan fiber reinforced composite yang dapat membantu meminimalisir pengasahan. Tujuan penelitian ini adalah untuk menganalisa perbedaan besar beban maksimum yang dapat diterima dan gambaran fraktur yang terjadi pada restorasi Fiber Reinforced Composite Rigid Fixed Bridge (FRCRFB) inlay retainer dengan pemakaian 1 lapis, 2 lapis, dan 3 lapis fiber yang menggantikan kehilangan satu gigi posterior (premolar 2/P2). Penelitian eksperimen laboratorium dilakukan pada bulan Juni 2012 di Laboratorium Ilmu Material Kedokteran Gigi (PPMKG) dan Klinik Prostodonsia FKG UI. Spesimen terdiri dari 27 restorasi FRCRFB dengan inlay retainer yang dibuat di atas master model yang terdiri dari abutment premolar 1 dan molar 1 kanan atas, yang sudah dipreparasi dengan ukuran panjang mesio-distal kavitas inlay pada gigi P1 4mm, lebar bukal-lingual 4mm, dan kedalaman 3mm; panjang mesio-distal kavitas inlay pada gigi M1 6mm, lebar bukal-lingual 4mm, dan kedalaman 3mm. Panjang span / celah interdental sebesar 7mm sebagai ruang bagi P2. Uji tekan dilakukan dengan Universal Testing Machine Shimadzu AG 5000 E, crosshead speed 1mm/menit. Hasil penelitian menunjukkan ketahanan terhadap fraktur dengan rerata besar beban maksimum yang dapat diterima oleh restorasi dengan 1 lapis fiber 607,16N, rerata terbesar yaitu 694,10N yang diterima oleh resotrasi dengan 2 lapis fiber, dan rerata terkecil yaitu 587,58N yang diterima oleh restorasi dengan 3 lapis fiber, dengan nilai p>0,05. Sehingga disimpulkan bahwa tidak terdapat perbedaan yang signifikan terhadap ketahanan fraktur dari restorasi FRCRFB dengan inlay retainer baik pada pemakaian 1 lapis, 2 lapis, maupun 3 lapis fiber. Gambaran fraktur terjadi mayoritas pada daerah pontik.

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In dental practice, it is frequently found patient with missing one posterior teeth that need rehabilitation with Fixed Partial Denture (FPD), but the patient request minimal tooth preparation on the abutment. Therefore the alternative restoration with fiber reinforced composite was introduced, that only require minimal tooth preparation. The purpose of this study was to evaluate fracture resistance and fracture path of Fiber Reinforced Composite Rigid Fixed Bridge (FRCRFB) with inlay retainer with different quantity of fiber application as reinforcement. The specimen were divided into three groups (n=27) which are restored with1, 2, and 3 layers of fiber application to rehabilitate missing one posterior teeth (2nd premolar). The specimen consist of 27 restoration FRCRFB with inlay retainer that has been made upon master model which consist of 1stupper right premolar and 1stupper right molar abutment. The master model preparation was as followed: inlay cavity on 1st premolar was 4mm in width of mesio-distal, 4mm in width of bucal-lingual, and 3mm deep; inlay cavity on 1st molar was 6mm in width of mesio-distal, 4mm in width of bucal-lingual, and 3mm deep; the interdental gap was 7mm. Compressive test was done by Universal Testing Machine Shimadzu AG 5000 E, crosshead speed 1mm/minutes. The result shown fracture resistance of 2 layers of fiber application was the highest with mean 694,10N, followed by 1 layer of fiber application (mean 607,16N), and 3 layers of fiber application (mean 587,58N), with p>0,05. The majority fracture path was on the pontic site. Therefore it could be concluded that there was no significant difference of fracture resistance of restoration FRCRFB with inlay retainer with different quantity of fiber application. The fracture part mostly found in pontic area."

"laminating technology is combining two or more of the same material or different mechanical properties and fisis. The method used is laminated horizontally laminated bending test (bending) where the size and shape to follow the rules of press ASTM test specimens (ASTM D 143)...."

"This book presents the bending theory of hyperelastic beams in the context of finite elasticity. The main difficulties in addressing this issue are due to its fully nonlinear framework, which makes no assumptions regarding the size of the deformation and displacement fields. Despite the complexity of its mathematical formulation, the inflexion problem of nonlinear beams is frequently used in practice, and has numerous applications in the industrial, mechanical and civil sectors. Adopting a semi-inverse approach, the book formulates a three-dimensional kinematic model in which the longitudinal bending is accompanied by the transversal deformation of cross-sections. The results provided by the theoretical model are subsequently compared with those of numerical and experimental analyses. The numerical analysis is based on the finite element method (FEM), whereas a test equipment prototype was designed and fabricated for the experimental analysis. The experimental data was acquired using digital image correlation (DIC) instrumentation. These two further analyses serve to confirm the hypotheses underlying the theoretical model. In the books closing section, the analysis is generalized to the case of variable bending moment. The governing equations then take the form of a coupled system of three equations in integral form, which can be applied to a very wide class of equilibrium problems for nonlinear beams. "

"Dalam berbagai jenis konstnxksi, banyak sekali digunakan struktur beton bertulang.. disamping keuntungan dalam pemakaian beton bertulang, salah satunya adalah karena pembangunan struktur beton bertulang lebih mudah dalam pelaksanaanya. Namun pada kenyataannya di Iapangan, tak sedikit kerusakan yang terjadi pada stuktur beton bertuiang. Kerusakan tersebut dapat disebabkan oleh banyak hal, diantaranya adalah kerusakan yang disebabkan oleh pengaruh Esika, mekanika, dan kimia.Pembahasan pada skripsi ini mengambil fokus kerusakan akibat pembebanan berlebih (overload). Untuk menangani kerusakan tersebut akan dilakukan perbaikan struktur beton bertulang dengan menggunakan bahan perbaikan concresive1438, Injection Resin LPL sebagai bahan perbaikan, dan M-Brace Laminate sebagai bahan perkuatan Perbaikan yang akan dilakukan adalah dengan metode injeksi dan perekatan bahan perkuatan pada sisi bawah balok.Penelitian yang akan dilakukan, selain didasarkan pada studi literatur, juga dilakukan simulasi perbaikan balok dengan melakukan perbaikan modul balok yang telah runtuh diikuti dengan pengujian guna mendapatkan kinerja dan kapasitas dari balok perbaikan tersebut. Hasil dari penelitian minimal hams sama dengan perilaku balok beton utuh.Simulasi dan pengujian yang telah dilakukan menunjukkan bahwa balok yang mengalami perbaikan dengan material concresivel438, Injection Resin LPL, dan M-Brace Laminate, memiliki I-cinerja yang baik apabila digunakan secara bersamaan. Sehingga dapat digunakan pada pekerjaan perbaikan kerusakan struktur akibat pembebanan berlebih.

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In many kind of construction, lots of themuse reinforced concrete structure. One of the benefits of using reinforced concrete is it has high workability. Nevertheless in reality, damage in reinforced concrete did happened. The damage could be cause by lots of factors, some of them caused by physical, mechanical? and chemical affection.The study in this thesis lakes focus on damage caused by overloading. To handle the damage, a reparation will be taken using Concresive 1438 and Injection Resin LPL as repairing material, and M-Brace Laminate as strengthening material.The reparation will be done using the injection method and bonding tl1e strengthening material at the bottomside of the beam.The study taken not only based on literally study, but also on beam repairing simulation, by conducting reparation on beam modul, which has been failure, followed by test to get the ability and cappacity of the repaired beam. The result of the study must have the minimun strength as the normal beam.The smulation and test that have been conducted, shows tat the beamthat have been repaired with Concresive 1438, Injection Resin LPL, and M-Brace Laminate material has better results. So the repairing method can be used to repair damage on reinforced concrete structure caused by overloading."