No abstract

A finite element formulation is presented for modeling the dynamic as well as static response of a compressor blades subjected to extension, bending and torsional loads. The formulation is derived from the variational principle with the consideration for the total potential energy of the structure based on the classical lamination theory. The compressor blade is modeled as an advanced beam with idealized rectangular cross-section that takes the warping effect into consideration. The bending-torsion coupling is introduced in the stiffness and mass matrices. A one dimensional linear isoparametric element with hermit cubic shape function is used. A two end nodes and one intermediate node as well is implemented for the finite element formulation. A Matlab interactive code was developed to solve a blade with a multi action loads. The results obtained are compared to the available analytical and finite element results.

No abstract

Penggunaan serat alam sebagai reinforcement pada material komposit semakin diminati pada satu dasawarsa terakhir ini. Hal ini disebabkan karena serat alam lebih ramah lingkungan ,memiliki densitas yang rendah, kompatibel dengan alam, dan harganya yang relatif murah. Salah satu penggunaan serat alam pada material komposit adalah serat kulit pohon waru (hibiscus tiliaceus). Kekuatan komposit serat kulit pohon waru (hibiscus tiliaceus) tidak hanya dipengaruhi oleh reinforcement dan komposisi antara serat-resin, akan tetapi juga dipengaruhi oleh jenis resin sintetis yang digunakan.Serbuk Alumina (Al2O3) adalah salah satu contoh material filler yang sering digunakan pada material komposit.Tujuan dari penelitian ini adalah mengetahui pengaruh penambahan serbuk alumina (Al2O3) terhadap energi impact yang diserap ,harga impact dan patahan komposit kulit pohon waru. Metode yang digunakan dalam penelitian ini adalah metode eksperimental.Dalam penelitian ini peneliti menginginkan pemanfaatan serat kulit pohon waru sebagai bahan alternatif penguat komposit. Dari hasil pengujian impact didapatkan energi yang diserap komposit serat kulit pohon waru (Hibiscus tiliaceus) variasi penambahan serbuk alumina metode vacumm infusion resin tertinggi pada variasi penambahan serbuk alumina 5 gram yaitu sebesar 10240,44 Joule. Dari hasil pengujian impact didapatkan harga impact komposit serat kulit pohon waru (Hibiscus tiliaceus) variasi penambahan serbuk alumina metode vacumm infusion resin tertinggi pada variasi penambahan serbuk alumina 10 gram  yaitu sebesar 90,98 Joule/mm2. Pola Patahan pada komposit uji impact dari variasi penambahan sebuk alumina metode vacumm infusion resin menunjukan mekanisme fiber pull out pada variasi 7,5 gram dan delaminasi pada variasi 5 dan 10 gram

Research on natural fiber composites is being carried out in various parts of the world to produce solutions to environmental problems by utilizing natural fiber materials prepared for environmentally friendly and renewable materials. The natural fiber currently being developed for composite reinforcement is hibiscus bark fiber. This study aims to determine the effect of the flow rate of bisphenol A resin LP-1Q-EX on the vacuum infusion resin method on the tensile strength of hibiscus bark fiber composites. The method used in this study is the fiber structure model in the direction of tensile load, composite using hibiscus bark fiber (Hibiscus tiliaceus), composite using bisphenol A resin LP-1Q-EX, composite using mass fraction with a ratio of 60 fibers: 40 resin, Waru tree bark was treated with 6% NaOH alkaline soaking (aquades 938.8 grams, and NaOH 61.2 grams) for 120 minutes, the number of hibiscus tiliaceus bark fibers in one composite material was 22 fibers with a material thickness of 3.2 mm (according to ASTM D638-03 Type 1 standard), the composite was produced using the vacuum infusion resin method with variations in resin flow rate of 1.19 ml/s, 3.66 ml/s, 4.67 ml/s. The testing process in this study is a composite tensile test using the ASTM D638-03 Type I standard. The analysis of the fractures that occur in each specimen uses macro photos, namely the process of taking several photos of the fracture after the specimen is subjected to a tensile test using a digital camera placed on the ground. topped a tripod. The results of the composite tensile test showed that the variation of resin flow rate of 1.19 ml/s had the lowest tensile strength of 282.94 MPa, while the variation of flow discharge of 3.66 ml/s had the highest tensile strength of 301.75 MPa. and the flow variation of 4.67 ml/s has a tensile strength of 284.54 MPa. Based on the results of the tensile test of the hibiscus tiliaceus bark fiber composite using the vacuum infusion resin method, the highest strength was obtained at a variation of the resin flow rate of 3.66 ml/s.