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"Horizontal shear interaction between profiled steel sheeting and concrete in composite slab is obtained through various means, such as frictional resistance due to indentation or embossment in the sheeting, interlocking at the steel and concrete interface resulting from curvature and shape of the sheeting profile under bending, and anchorage devices such as welded shear studs and crippled sheeting at the end of the span. Permanent end pour stops may provide some restraining effect to the slipping of the concrete, and hence may enhance the composite action. Despite the use of many types of devices, most reported test results of typical length composite slabs still exhibit partial shear interaction. This paper reports the enhancement of the horizontal shear interaction at the concrete-profiled steel sheeting interface of composite slab by using shear screws. Six full scale bending tests were conducted of which three specimens with different slenderness were enhanced with self drilling screws while another three were without screws. The test results show that the failure mode of composite slab can be improved to ductile type and the load carrying capacity can be increased by the presence of the shear screws. The load performance of the slab is also affected by the slenderness, which is the ratio of shear span to effective depth."

"ABSTRAKNatural fiber reinforced polymer composites are widely developed because of their relative low price and eco-friendly. One of natural fiber sourches is pandanus tectorius leaf. This study aimed to determine the effect of variations in fiber volume fraction on tensile strength, impact strength, bending strength and morphological on sea pandanus fibers- polypropylene composites.Tensile test spesimen refer to ASTMD 638, impact test spesimen refes to ASTMD 5942-96, bending test spesimen refer to ASTMD 790 -02. The increasing of the volume fraction increased the tensile strength and impact strength. The tensile test results showed the highest tensile strength results for composites with a volume fraction of 35% was 25.82 MPa. The impact test results showed that the highest impact strength was obtained in the 35 % volume fraction of 0.0062 Joule/mm2. The bending test results showed that the highest bending strength was obtained in the 20% volume fraction of 24.96 MPa. Based on SEM test results, there were voids, cracks, fibers pull out on the composite."

"Penelitian ini bertujuan untuk mengevaluasi pengaruh durasi penyinaran terhadap kekuatan tarik diametral resin komposit bulk-fill. Enam puluh spesimen Tetric N-Ceram Bulk-Fill ketebalan 3 mm dan diameter 6 mm; warna IVA dan IVW dibagi ke dalam 3 kelompok berdasarkan durasi penyinaran 10 detik, 15 detik, dan 20 detik untuk setiap warna. Spesimen dipolimerisasi dengan LED curing unit Bluephase Style, 1.280 mW/cm2 dan diuji kekuatan tarik diametralnya menggunakan uji statistik Universal Testing Machine. Data yang diperoleh dianalisis menggunakan One-Way ANOVA dan Post-Hoc Tukey HSD. Hasil menunjukkan adanya perbedaan bermakna.

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This study was conducted to evaluate the influence of different exposure time and bulk fill composite shade on its diametral tensile strength. Sixty disc shaped specimens of Tetric N Ceram Bulk Fill 3 mm of thickness x 6 mm of diameter shade IVA and IVW were divided into 3 subgroups for each shade according to exposure times 10 s, 15 s, and 20 s . All specimens were polymerized using LED curing unit Bluephase Style, 1.280 mW cm2 and tested using Universal Testing Machine to determine its diametral tensile strength. Data were statistically analyzed using One Way ANOVA dan Post Hoc Tukey test. The result showed a significant differences in all groups."

"Karakterisasi Komposit AC4B/Nano TiC Dengan Variasi Fraksi Volume Nano TiC Reinforce oleh Stir Casting Process telah diselidiki. Penulis digunakan paduan aluminium seri tiga, AC4B, yang mengandung silikon dan tembaga sebagai paduan utamanya. Selanjutnya, penambahan Nano TiC ke dalam komposit AC4B dapat meningkatkan daya tarik kekuatan, daktilitas, dan ketangguhan komposit AC4B dengan menyempurnakan struktur dendrit dari fase α-Al dan membentuk fase padat super jenuh, θ (Al2Cu). Dalam studi ini, Komposit AC4B / Nano TiC dibuat melalui stir casting dengan beberapa variabel parameter Nano TiC memperkuat komposisi 0,25%, 0,3%, 0,35%, 0,4%, dan 0,5% fraksi volume untuk menentukan nilai optimal dari sifat mekanik AC4B/komposit Nano TiC. Proses casting stir dipilih karena memiliki beberapa kelebihannya, seperti mudah digunakan, fleksibel, dan dapat digunakan untuk menghasilkan sejumlah besar produk. Diketahui bahwa komposit AC4B/Nano TiC memiliki nilai optimum sifat mekanik ketika komposisi Nano TiC adalah fraksi volume 0,3% dengan kekuatan tarik utama 132,31 MPa dan kekerasan 55,18 HRB.

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Characterization of AC4B/Nano TiC Composites with Variations in Reinforce Nano TiC Volume Fractions by the Stir Casting Process has been investigated. The author used three series aluminum alloy, AC4B, which contained silicon and copper as its main alloy. Furthermore, the addition of Nano TiC to the AC4B composite can increase the tensile strength, ductility, and toughness of the AC4B composite by perfecting the dendrite structure of the α-Al phase and forming a super saturated solid phase, θ (Al2Cu). In this study, AC4B/Nano TiC composites made by stir casting with several variable parameters Nano TiC strengthens the composition of 0.25%, 0.3%, 0.35%, 0.4%, and 0.5% volume fraction to determine the optimal value of the properties mechanical AC4B/Nano TiC composites. The casting casting process was chosen because it has several

its advantages, such as easy to use, flexible, and can be used to produce a large number of products. It is known that the AC4B/Nano TiC composite has optimum mechanical properties when the composition of Nano TiC is a volume fraction of 0.3% with a main tensile strength of 132.31 MPa and a hardness of 55.18 HRB.

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"Rem adalah komponen vital dalam kendaraan yang berfungsi mengurangi kecepatan dan menghentikan kendaraan. Brake shoe yang diperoleh oleh industri umum saat ini terbuat dari besi cor, yang memiliki densitas dan gesekan tinggi yang menyebabkan terjadinya percikan selama pengereman. Dalam penelitian ini dipelajari mengenai sifat mekanik dan mikrostruktur ADC12 dengan komposit SiC mikro untuk menggantikan besi cor dalam pembuatan sepatu rem untuk kereta. Komposit dibuat dengan metode pengecoran aduk dan ditambahkan kandungan Ti 0.04, 0.06, 0.15, 0.3 dan 0.5 wt. TiB bertindak sebagai penghalus butir yang meningkatkan sifat mekanik secara signifikan karena butir menjadi lebih halus dan seragam. Sepuluh persen berat Magnesium ditambahkan untuk meningkatkan kemampubasahan dari komposit tersebut. Beberapa pengujian yang dilakukan untuk mengkarakterisasi material komposit adalah: OES, XRD, OM, SEM, dan pengujian merusak seperti tarik, kekerasan, keausan, danimpak. Hasilnya, komposisi optimum ditemukan pada komposit ADC 12/SiC dengan menambahkan 0.15 wt TiB yang menghasilkan UTS sebesar 136 MPa, kekerasan sebesar 53 HRB, laju aus sebesar 0.99 mm3/s, dan harga impak sebesar 0.097 J/mm2.

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Brake is a vital component in a vehicle that works on reducing speed and stopping the vehicle. Brake shoe obtained by common industries is currently made of a cast iron, which has a high density and a high friction that caused sparks during braking. The mechanical properties and microstructure of the ADC12 with micro SiC composites to replace cast iron in the making of brake shoe for train have been studied in this work. The composites were made with stir casting method and were added Ti content of 0.04, 0.06, 0.15, 0.3 and 0.5 wt. TiB act as grain refiners that improve the mechanical properties significantly because the grain becomes finer and more uniform and 10 wt Magnesium was added to improve the wettability of the composites. Several test were conducted to characterize the material OES, XRD, OM, SEM, and destructive test such as tensile, hardness, wear, and impact. As the result, the optimum composition was found by adding 0.15 wt of TiB which results 136 MPa in Ultimate Tensile Strength UTS , 53 HRB in hardness, 0.99 mm3 s in wear rate, and 0.097 J mm2 on impact testing."

"Penelitian ini bertujuan untuk mengetahui kekuatan rekat geser resin komposit serat sebagai substuktur dengan resin komposit partikulat berbeda komposisi. Resin komposit partikulat G-aenial posterior Kelompok A, 10 spesimen dan Tetric N-ceram Kelompok B,10 spesimen digunakan sebagai lapisan atas resin komposit serat EverX Posterior. Uji kuat rekat geser dilakukan menggunakan UTM dengan beban 100 kgf dan crosshead-speed 0.5 mm/menit. Data dianalisis menggunakan uji statistik independent sample t test. Hasil penelitian menunjukan nilai rerata kuat rekat geser yakni 18,64 1.5 MPa A dan 22,05 1,8 MPa B . Disimpulkan bahwa terdapat perbedaan kuat rekat geser yang bermakna pada kedua kelompok.

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The aim of this study was to identify shear bond strength fiber reinforced composite as a substructure with different composition of particulate filled composite. Particulate filled composite G aenial posterior Groups A, 10 specimen and Tetric N ceram Groups B, 10 specimen used as an upper layer of FRC EverX Posterior. Shear bond strength test was performed using UTM with a load of 100 kgf and crosshead speed of 0.5 mm min. Data were analyzed using statistical test independent sample t test. The result of this study showed the mean shear bond strength values are 18,64 1.5 MPa A and 22,05 1,8 MPa B . It was concluded that there is a significance difference of shear bond strength between two groups."

"Residual stresses are a common phenomenon in composite materials. They can either add to or significantly reduce material strength. Because of the increasing demand for high-strength, light-weight materials such as composites and their wide range of applications in the aerospace and automotive industries, in civil infrastructure and in sporting applications, it is critical that the residual stresses of composite materials are understood and measured correctly.The first part of this important book reviews destructive and non-destructive testing (NDT) techniques for measuring residual stresses. Various mathematical (analytical and numerical) methods for calculation of residual stresses in composite materials are also presented. Chapters in the first section of the book discuss the simulated hole drilling method, the slitting/crack compliance method, measuring residual stresses in homogeneous and composite glass materials using photoelastic techniques, and modeling residual stresses in composite materials. The second part of the book discusses residual stresses in polymer matrix, metal-matrix and a range of other types of composites. Moreover, the addition of nanoparticles to the matrix of polymeric composites as a new technique for reduction of residual stresses is discussed."

"The traditional fiber reinforced composite (FRC) contains bishpenol A glycidyl methacrylate (bis-GMA) in the resin matrix, which is thought to have some disadvantages. This research aimed at replacing bis-GMA with another monomer-urethane dimethacrylate (UED-MA), with the desired properties for dental use still retained. Four groups were prepared with light-curing (n = 30), one Control group with a bis-GMA-based resin matrix and three experimental groups with UEDMA-based matrices (Exper 1, Exper 2 and Exper 3 with a varying UEDMA weight percentage). Specimens were stored in dry conditions for 24 h or in deionized water for 1, 3, 6 or 12 months prior to the tests. Water sorption (n = 6), Vicker's hardness (n = 6) and flexural properties (n = 6) after each storage time were investigated.Scanning electron microscopy (SEM) images were taken at the fracture sites after 3-point bending. All the results were statistically analyzed (α = 0.05). The Exper 1 group exhibited the lowest weight increase after water storage among the experimental groups. As for dry conditions, 1- and 6-month storage, different resin matrix compositions made no significant difference to hardness, while for 3- and 12- month storage, "Control" possessed the highest hardness. The Control group's strength and modulus, Exper 1 and Exper 2's modulus were stable during water storage. Compared to other experimental groups, Exper 1 had the highest strength and modulus values with most of the storage times. SEM images showed relatively good adhesion between the fiber and the matrix. With all the tested properties considered, the Exper 1 group had superior performance among all the three experimental groups."

"Penelitian ini bertujuan mengembangkan Alat Tekan Panas (Hot-Press) untuk Proses pembuatan komposit matriks berpenguat serat panjang/tekstil dengan termoset (Thermoset Composite). Hasil Penelitian menunjukkan faktor tekanan dan temperatur yang dipakai pada pada proses tersebut merupakan penentu kekuatan dan kualitas dari produk komposit. Penelitian ini, juga memulai kasus kajiannya untuk Biodegradable Composite yang dibangun dari unsur-unsur matriks alam (PLA- PolyLactic Acid) dan serta penguat serat alam Ramie. Dari hasil pengembangan dan pengujian alat, Alat Cetak Tekan Panas dapat berfungsi dengan baik dan menghasilkan mutu produk komposit serat alam yang jauh lebih baik dibanding hand-lay-up dan relatif cukup murah (Low-cost manufacturing process).

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This study aims to develop a Hot-Press for the manufacturing process of a long fiber / textile reinforced matrix composite using a thermoset (Thermoset Composite). The results showed that the pressure and temperature factors used in the process were determinants of the strength and quality of the composite product. This research also started its case study for Biodegradable Composite which is built from natural matrix elements (PLA-PolyLactic Acid) and also Ramie's natural fiber reinforcement. From the results of the development and testing of the tool, the Heat Press Printing Tool can function well and produce quality natural fiber composite products that are far better than hand-lay-up and relatively cheap (Low-cost manufacturing process)."

"Komposit banyak digunakan dalam dunia teknik seperti penerbangan, otomotif, dan perkapalan. Penelitian pengaruh air laut terhadap kekuatan komposit sebagai material float pesawat amfibi telah dilakukan. Matriks yang digunakan adalah vinilester dan serat yang digunakan yaitu serat e-glass, karbon, dan hibrid kevlar-karbon. Komposit dibuat dengan teknologi vacuum infusion dengan komposisi e-glass/vinilester, hibrid e glass/karbon/vinilester, dan hibrid kevlar-karbon/karbon/vinilester. Komposit hibrid digunakan karena masih terbatasnya penelitian pengaruh air laut terhadap komposit tersebut. Komposit direndam dalam bak berisi air laut dengan lama perendaman sampai 6 bulan untuk mengetahui nilai penyerapan air laut. Pengujian tarik, tekan, dan geser dilakukan untuk mengetahui sifat mekanik komposit sebelum dan setelah perendaman. Uji SEM dan FTIR dilakukan untuk mengetahui struktur mikro komposit setelah pengujian dan mengamati ikatan molekul senyawa polimer sebelum dan setelah perendaman. Hasil penelitian menunjukkan penambahan berat maksimum komposit e-glass/vinilester, karbon/vinilester, e-glass/karbon/vinilester, dan karbon-kevlar/karbon/vinilester adalah 0,69%; 0,84%; 0,79%, dan 2,02%. Kekuatan tarik dan tekan tertinggi adalah komposit kevlar-karbon/karbon dengan nilai 513,84 MPa dan 267,98 MPa, sedangkan kekuatan geser tertinggi adalah komposit glass/karbon sebesar 109,03 MPa meskipun bedanya tidak terlalu jauh dengan komposit kevlar-karbon/karbon sebesar 104,32 MPa. Degradasi sifat mekanik terjadi pada semua komposit. Degradasi tertinggi pada semua komposit terjadi pada kekuatan tekan dengan persentase degradasi kekuatan tekan tertinggi pada komposit glass/vinilester. Degradasi sifat mekanik terjadi karena difusi air laut menyebabkan plastisisasi, degradasi matriks dan serat, debonding serat/matriks, dan crack. Indikasi ini terbukti dari analisa mikrostruktural terhadap permukaan patahan hasil uji tarik menggunakan SEM.

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Composites are widely used in the engineering world like aerospace, automotive, and marine. Research on the effect of sea water on the strength of composites as amphibious aircraft float material has been carried out. The matrix used is vinylester and the fiber used are e-glass, carbon and kevlar-carbon hybrid fiber. Composites are made with vacuum infusion technology with the types of composites are e-glass/vinylester, e-glass/carbon/vinylester, and kevlar-carbon/carbon/vinylester. Hybrid composites are used because research is still limited to the effect of sea water on these composites. Composites are immersed in a conatiner which contain natural seawater till 6 month to know the weight gain of water absorption in these. Tensile, compressive, and shear test are conducted to know teh mechanical properties of the composites before anda after immersion time. SEM and FTIR test are conducted to know composite microstructural after mechanical test and observe molecul bond of polimer before and after immersion. The results showed that the maximum weight gain of e-glass/vinylester, carbon/vinylester, e-glass/carbon/vinylester, and carbon-kevlar/carbon/vinylester composites were 0.69%; 0.84%; 0.79% and 2.02%, respectively. The highest tensile and compressive strength are kevlar-carbon/carbon composite: 513,84 MPa dan 267,98 MPa respectively, while the highest shear strength is glass/carbon composite: 109,03 MPa, although the difference is not too far from kevlar-carbon/carbon composite: 104,32 MPa. Degradation of mechanical properties occurred in all composites. The highest degradation in all composites occurred at compressive strength with the highest percentage of compressive strength degradation in glass/vinylester composites. Degradation of mechanical properties occurs due to diffusion of sea water causing plasticization, matrix and fiber degradation, fiber/matrix debonding, and cracking. Microstructural analysis using SEM micrograph supports this indication."