7 research outputs found
Respon Polymeric Foam yang Diperkuat Serat Tandan Kosong Kelapa Sawit (TKKS) Akibat Beban Tekan Statik dan Impak (Simulasi Numerik)
No full textExperimental and numerical work was reported on the problem of the
response of oil palm empty fruit bunch (OPEFB) fiber reinforced polymeric foam
under static and impact loading conditions. In the experimental investigation, the
static axial compressive test was applied on polyurethane, thermosetting resins, and
OPEFB fiber reinforced polymeric foam specimens and these specimens were
conducted on a servohydraulic material testing machine. The averaged stress-strain
response and the fracture modes in each type of materials were derived from static
test. The fracture modes in each type of materials and the collapsed cells of OPEFB
fiber reinforced polymeric foam were observed by a scanning electron microscope. In
the numerical simulation, the variation of the distributions of normal stresses with
normalized time in OPEFB fiber reinforced polymeric foam due to static and impact
wave propagation was analyzed by using a finite element method (FEM). The finite
element code ANSYS and NASTRAN were used for numerical stress analysis. The
obtained summaries were as followed: (1) The yield stress, the maximum stress, and
the strain to failure were influenced by foams, these foams reduced the stress and
decreased the strain to failure. The fracture modes were also found to be
considerably different for each type of materials. Polyurethane exhibited random
macroscopic fracture, thermosetting resins and OPEFB fiber reinforced polymeric
foam exhibited shear dominated failure and the cells suffered progressive crushing.
(2) Based on FEM computation results were found that the fracture mechanism
corresponded to the regions of the static compressive stress concentration. (3) FEM
computation results suggested that the propagation of incident compressive stress
wave related to impact loading. (4) Based on the static axial compressive test results,
the Young’s modulus and the stiffness were determined and it was found that
thermosetting resins may also contributed to increased the stiffness of polyurethane.Penelitian secara eksperimen dan numerik telah dilaporkan untuk menyelidiki
permasalahan respon polymeric foam diperkuat serat tandan kosong kelapa sawit
(TKKS) akibat pembebanan kondisi pembebanan statik dan impak. Di dalam
penyelidikan secara eksperimen, pengujian tekan statik aksial digunakan terhadap
spesimen polyurethane, resin termoset, dan polytmeric foam diperkuat serat TKKS
dan pengujian spesimen tersebut dilakukan pada mesin uji material servohidraulik.
Respon tegangan-regangan rata-rata dan mode kerusakan setiap material diperoleh
dari uji statik. Mode kerusakan setiap material dan kehancuran rongga polymeric
foam diperkuat serat TKKS diamati menggunakan scanning electron microscope. Di
dalam simulasi numerik, variasi distribusi tegangan normal terhadap waktu pada
polymeric foam diperkuat serat TKKS akibat beban statik dan propagasi gelombang
impak akan dianalisa menggunakan metode elemen hingga (MEH). Elemen hingga
dengan kode ANSYS dan NASTRAN digunakan dalam analisa tegangan secara
numerik. Kesimpulan yang diperoleh dari penelitian ini sebagai berikut: (1) Tegangan
yield, tegangan maksimum, dan regangan saat patah dipengaruhi oleh rongga, rongga
tersebut mereduksi tegangan dan menurunkan regangan saat patah. Mode kerusakan
ditemukan sangat berbeda untuk setiap jenis material. Polyurethane menunjukkan
kerusakan yang acak secara makroskopik, resin termoset dan polymeric foam
diperkuat serat TKKS menunjukkan dominasi kegagalan geser dan rongga-rongga
mengalami kerusakan bertahap. (2) Berdasarkan hasil simulasi MEH ditemukan
bahwa mekanisme kerusakan bersesuaian dengan daerah konsentrasi tegangan tekan
statik. (3) Hasil komputasi FEM menyarankan bahwa propagasi gelombang tegangan
insiden tekan berhubungan dengan beban impak. (4) Berdasarkan hasil uji tekan
statik aksial, modulus elastisitas dan kekakuan telah ditetapkan dan ditemukan bahwa
resin termoset berkontribusi meningkatkan kekakuan polyurethane.178 HalamanTesis Magiste
Manufaktur Bodi Kendaraan Shell ECO Marathon (SEM) Tipe Urban Bahan Komposit Serat Karbon
No full textIn the development of manufacturing industry the use of composite materials began to be widely used. One of them is composite by using fiber glass or fiber carbon, because of its characteristic that can be designed close to certain needs. In addition the specific strength and stiffness are far exceeding the engineering material in general. This research uses carbon fiber composite material as vehicle body material Shell Eco Marathon (SEM), Which a fraction volume of 70% resin polyester and 30% of carbon fiber. The composite is made using Hand Lay Up method that produces vehicle body SEM of consist of main frame and styrofoam. The result of manufacturing the SEM vehicle body is obtained, so that it can be used as an Urban SEM vehicle body
Analisis Sifat Mekanik Komposit Serat Sabut Kelapa sebagai Material Alternatif Pengganti Kayu untuk Pembuatan Kapal Tradisional
No full textRecently, it has been difficult to get the wood as a material to construct the traditional ships. Alternatively, the wood can be substituted by composite materials such as the composite of coco fiber. The coco fiber composites have potential to construct a fishing boat. In this research produced the composite plates and investigation of their value of tensile strength and flexural strength. The composite composition was used 70% polyester and 30% coco fiber. Production of the composite plates used Vacuum Assisted Resin Infusion (VARI) method by variation of the direction of fibers (random, continous and woven). Based on the research result that was produced the composite plates sizes of 400 x 400 x 8 mm and the value of tensile strengths of composite coco fiber for random fiber direction of 12.8572 N/mm2, continuous fiber direction of 15.4436 N/mm2 and woven direction of 12.1797 N/mm2. The value of flexural strengths for random fiber direction was 97.3220 N/mm2, continuous fiber direction of 96.1347 N/mm2 and woven fiber direction of 80.3922 N/mm2. In conclusion, the value of the highest tensile strength and the highest flexural strength were a continuous fiber direction and a random fiber direction, respectively
Desain dan Penentuan Lokasi Pembebanan Pendulum Alat Uji Impak untuk Pengujian Produk Hasil Las Gesek Rotary Bar-Plate
No full textFracture that occurred in bar-plate friction welding joint on component, be it with a similar or dissimilar materials, can be reviewed by destructive testing. One of the destructive test on weld joint by friction welding is the impact test. Pendulum of standart Charpy and Izod is not match to use for it. Therefore, in this study was made the design and set up pendulum of impact testing for it, using the finite element method software, by considering dynamic factors that may affect fracture such as, loading angle, loading point on the product bar-plate, the dimensions of pendulum, maximum stess thet occurs, and the mass variation of the pendulum. The Obtain summaries are as follows: (1) Results of the Pendulum tests, it was safe to use, it was qualyfied for pendulum impact testing, and plastic deformation was not occurs on entire pendulum. (2) Based on tests result, loading point (x) at 10mm, affected fracture between bar and plate in HAZ section, while loading point at 40 mm until 15 mm affected fracture on plate, not on the section between bar and plate
Desain Alat Uji Impak Struktur Las Gesek Bar-Plate Menggunakan Bantuan Computer Aided Engineering (CAE)
No full textFriction Welding is one of the well known press welding methods, where the method is joining two pieces of metal materials. By in this method the heat resulted from the change in mechanical energy into thermal energy in the field of interface the workpiece due to friction during motion plays under pressure/friction. Rotaryfriction welding is made from bar-plate specimens and its products tested by tensile test but not optimal because the weld test objects attached again by adding one bar on the other side, so that acquired way of knowing the characteristics of friction welding the connection using the impact test, so it required the design and manufacture of tools the impact test that aims to get the construction design and the impact tester of friction welding structure of bar-plate. Construction design includes chassis, axle, fixture, and a disc Binder then simulated using ANSYS to view voltage that occurs in the design does exceed the allowed voltage. The component designer is simulated order and the fixture result States that voltage happens during testing does not exceed the allowed limits, it is stated that decent design is created. Impact tester created then tested, and the results stated that no failure occurred on the tools in the form of a broken or cracked, so the impact tester that are worth to be used
Pengaruh Variasi Kecepatan Putaran Benda Kerja dan Kedalaman Pemakanan Terhadap Kekasaran Permukaan Proses Gerinda Silinderis dengan Center Pada Baja AISI 4140
No full textGerinda silinderis adalah proses mendasar pada pemesinan akhir sebuah komponen yang memerlukan kekasaran permukaan yang halus dan toleransi yang presisi. Variasi parameter proses penggerindaan silinderis antara lain kecepatan putaran benda kerja dan kedalaman pemakanan. Prinsip kerja penggerindaan sama dengan proses pemotongan benda kerja, pisau atau alat potong gerinda adalah batu gerinda yang tersusun dari partikel abrasive yang saling melekat. Penelitian gerinda silinderis ini menggunakan parameter yang divariasikan, yaitu tiga variasi kecepatan putar benda kerja 83 rpm, 194 rpm, 304 rpm dan tiga variasi kedalaman pemakanan, 0,005 mm, 0,010 mm, 0,015 mm. Nilai rata-rata kekasaran permukaan hasil penggerindaan silinderis Baja AISI 4140 berdasarkan toleransi nilai kekasaran permukaan rata-rata/Ra adalah sebagai berikut: Kelas kekasaran N7, Harga Ra 1,6, Toleransi (μm) (+50%&-25%) adalah 1,2 – 2,4, Panjang sampel 0,8 mm. Tingkat kekasaran rata-rata permukaan menurut proses pengerjaannya hasil gerinda silinderis Baja AISI 4140 adalah sebagai berikut: Proses Pengerjaan: finishing, Selang (N) N4-N8, Harga Ra 0,1 – 3,2. Parameter kecepatan putaran benda kerja dan kedalaman pemakanan yang terbaik untuk pengujian kekasaran permukaan proses gerinda silinderis Baja AISI 4140 adalah kecepatan putar benda kerja 194 rpm dan kedalaman pemakanan 0,010 mm. Berdasarkan analisis ANOVA Dua Arah, variabel yang paling berpengaruh pada penelitian ini yaitu Kecepatan Putar Benda Kerja dengan Signifikansi (Sig.) adalah 0,000 (Ftabel = 12,470) dibanding Kedalaman Pemakanan dengan Signifikansi (Sig.) adalah 0,001 (Ftabel = 11,030).
Kata kunci : Gerinda Silinderis, Kecepatan Putar Benda Kerja, Kedalaman Pemakanan, Kekasaran Permukaan
Penyelidikan Kekuatan Tekan dan Laju Keausan Komposit dengan Filler Palm Slag sebagai Bahan Penyusun Kanvas Rem Sepeda Motor
No full textPalm slag as waste burning of palm shells and bunches for boiler fuel is available in abundance. Availability of abundant is potential to be developed as a filler of brake composite. The using of palm slag as filler composite non-asbestos brake pads have been studied and potential to be used as a substitute for asbestos brake pads motorcycle. The purpose of this study was to determine the effect of variations in the initial compacting pressure and sintering temperature on the compressive strength and the wear rate of the composite. In this study the manufacture of composite brake using materials with a composition of 40% palm slag, 20% steel powder, 20% phenolic resin, 10% alumina, and 10% graphite. Manufacture of composites using powder metallurgy techniques by varying the compaction pressure at 254, 508, and 762 MPa, and sintering temperatures of 150, 160, and 170oC. Increasing compaction pressure and sintering temperature does not always affect the compressive strength and the wear rate of composite brake. Initial compaction pressure affecting the increase in compressive strength is 508 MPa at 150 and 160oC sintering temperature. Initial compaction pressure affecting decrease the wear rate is 254 and 508 MPa at sintering temperatures of 150 and 160oC
