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Abstrak :
Pengujian fatigue dilakukan pada material komposit fiber glass berjenis woven roving dengan epoxy sebagai matriksnya. Material yang diuji merupakan material yang lolos uji pada serangkaian uji mekanik statis sebelumnya, yaitu WR 200 asimetris epoxy dan WR 400 asimetris-epoxy. Material ini dibuat dengan metode Vacuum Assisted Resin Infusion (VARI) pada suhu ruang. Hasil pengujian fatigue dilanjutkan dengan ekstrapolasi data dari kurva S-N dengan Matlab 7.4 yang berisi curve fitting probabilitas kegagalan untuk memperkirakan masa pakai material. Hasil curve fitting menunjukkan material mempunyai daya tahan di atas siklus 108 untuk pemakaian sekitar 20 tahun. Hasil pengamatan dengan mikroskop optik dan Scanning Electron Microscope (SEM) menunjukkan mekanisme kegagalan material akibat uji fatigue, diawali dengan retaknya matriks, putusnya ikatan permukaan matriks-fiber, diikuti putusnya fiber yang menyebabkan patahnya material. ......Fatigue test was carried out on composite materials with the type of woven roving fiberglass with an epoxy as a matrix. The specification of the fatigue tested materials was selected from previous static mechanical tests, namely WR 200 asymmetric-epoxy and WR 400 asymmetric-epoxy. These materials were produced by using Vacuum Assisted Resin Infusion (VARI) at room temperature. The fatigue test result followed by extrapolation of data from the S-N curve with Matlab 7.4 curve fitting, which contains the probability of failure to estimate the lifetime of the materials. Curve fitting results indicate the materials have a resistance above 108 cycles for the use of about 20 years. The observation with optical microscope and Scanning Electron Microscope (SEM) shows the mechanism of failure due to fatigue test, begins from a matrix cracking, followed by a fiber-matrix interfacial debonding, then a fiber breakage that caused the final fracture.

Abstrak :
This book provides a concise discussion of fatigue crack growth (FCG) failure and lifing analysis methods for metallic aircraft structures and components. After a reasonably concise historical review, surveys are made of (i) the importance of fatigue for aircraft structural failures and the sources of fatigue nucleation and cracking, (ii) contemporary FCG lifing methods, and (iii) the Quantitative Fractography (QF) required for determining the actual FCG behaviour. These surveys are followed by the main part of the book, which is a discussion, using case histories, of the applicabilities of Linear Elastic Fracture Mechanics (LEFM) and non-LEFM methods for analysing service fatigue failures and full- and sub-scale test results. This discussion is derived primarily from the experiences of the Defence Science and Technology Group in Melbourne, Australia, and the Netherlands Aerospace Centre, Marknesse, the Netherlands.

Abstrak :
ABSTRAK
Teknik untuk mengetahui RFL remaining fatigue life memiliki beberapa cara antara lain dengan teknik thermography. Dalam studi ini telah dilakukan completely rotating bending fatigue testing sesuai dengan standart JIS Z2274 untuk mengukur nilai Nf Fatigue Life dan untuk mengestimasi nilai RFL dengan teknik thermography. Selama pengujian dengan teknik thermography, perubahan temperature benda uji pada titik kritis diukur dengan menggunkan infrared kamera. Dari hasil pengukuran perubahan temperature tersebut telah dilakukan estimasi nilai RFL. Material yang dipakai adalah S45C. Pengujian dilakukan dalam putaran 1600 rpm dengan kondisi suhu lingkungan 25 C. Akhirnya dapat disimpulkan bahwa nilai RFL hasil estimasi dengan teknik thermograpy sangat mendekati dengan nilai RFL hasil pengujian.

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ABSTRACT
There are several techniques to estimate the RFL remaining fatigue life such as thermography techniques. In this study, rotating bending fatigue testing has been done completely with the standard JIS Z2274 to measure the value of Nf Fatigue Life and to estimate the value of the RFL using thermography techniques. During the testing with the techniques, the positive of temperature gradient of the specimen at the critical point is measured by using the infrared camera. From the result of temperature change, the RFL value can be estimated. The material used is S45C. The test is carried out in 1600 rpm with ambient temperature of 25 C. Finally, it can be concluded that the estimated RFL value with thermograpy technique is very close to the value of RFL test result.

Abstrak :
Bagian midship kapal adalah bagian yang mengalami pembebanan yang paling intggi saat kapal berlayar. Pada kapal tanker, dibutuhkan ketahanan pelat berpenegar yang kuat supaya saat kapal beroperasi, kapal dapat membawa muatannya dengan aman. Pembebanan yang biasanya terjadi pada kapal adalah sagging dan hogging di mana beban tersebut termasuk kategori beban siklik dan dapat mengakibatkan kegagalan lelah. Penelitian ini berfkous pada analisis ketahanan lelah dalam studi pengaruh posisi semi eliptical crack pada pelat berpenegar dengan profil konventional T dan novel Y. Semi elliptical crack ditempatkan pada bagian tengah pelat, seperempat jarak dari profil, dan berdekatan dengan profil. Simulasi pembebanan dilakukan dengan metode numerik dengan menggunakan perangkat lunak ANSYS untuk memprediksi ketahanan lelahnya. Hasil menunjukan bahwa crack di tengah profil memiliki ketahan lelah yang terburuk sehingga memiliki umur lelah yang pendek dibandingkan posisi crack yang lain.

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The ship 39 s midship section is the part that experiences the most loads while sailing. For tankers, it is necessary to have high fatigue endurance in the ship structure especially on the stiffend panel so that the ship can carry its load cargo safely. The loads that generely experienced by the midship are sagging and hogging. This load is categorized as cyclic load which can result in fatigue failure. This study focuses on the analysis of fatigue resistance in the study of the effect of semi eliptical crack position on the stiffened panels with conventional profile of T and novel profile of Y. Semi elliptical cracks are positioned on the center of the plate, a quarter distance from the profile , and adjacent to the profile. The simulation of loading uses ANSYS to predict its fatigue resistance. The result shows that the crack in the middle of the plate has the worst fatigue resistance which results in having a short fatigue life compared to the other crack.

Abstrak :
Bagian Midship kapal adalah bagian yang mengalami pembebanan paling tinggi saat kapal berlayar di laut. Pada kapal tanker dibutuhkan kekuatan fatik yang lebih besar karena pembebanan siklik terjadi dengan skala besar saat operasinya. Penelitian ini berfokus pada ketahanan fatik pada bagian midship kapal tanker dengan penegar novel tipe Y yang memiliki nilai section modulus sama dengan penegar konvensional tipe T. Penegar Y akan divariasikan terhadap massa dan mengacu pada massa penegar T untuk mengetahui nilai section modulus serta ketahanan fatiknya. Simulasi pembebanan sendiri dilakukan dengan metode numerik dengan perangkat lunak ansys untuk memprediksi ketahanan fatiknya. Hasil menunjukkan bahwa bentuk geometri T memiliki ketahanan yang lebih baik dibandingkan penegar Y dengan nilai section modulus yang sama. Variasi dengan penegar Y yang memiliki massa yang sama dengan penegar T memiliki nilai section modulus yang lebih besar serta ketahanan fatik yang lebih kecil dibandingan kedua penegar lainnya.

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The midship section of the ship is the part that occurs the highest loading while the ship sails at sea. In tankers type, it requires higher fatigue strength because cyclic loading occurs on a large scale during its operation. This study focuses on fatigue strength in the midship section of tankers with Y novel stiffener, which have the same modulus section value as the conventional T type stiffener. The Y stiffener will be varied by referring the mass of the T to determine the value of the modulus section and the fatigue strength. The loading simulation process is done by finit element method with ansys software to predict fatigue life and damage. The results show that the T type has better life than Y type stiffener which has the same modulus section value. The variation with the Y Stiffener, which have the same mass as the T stiffener, has a higher modulus section value but lower fatigue strength than the two other stiffeners.

Abstrak :
It is commonly accepted that the majority of engineering failures happen due to fatigue or fracture phenomena. Adhesive bonding is a prevailing joining technique, widely used for critical connections in composite structures. However, the lack of knowledge regarding fatigue and fracture behaviour, and the shortage of tools for credible fatigue design, hinders the potential benefits of adhesively bonded joints. The demand for reliable and safe structures necessitates deep knowledge in this area in order to avoid catastrophic structural failures. This book reviews recent research in the field of fatigue and fracture of adhesively-bonded composite joints. The first part of the book discusses the experimental investigation of the reliability of adhesively-bonded composite joints, current research on understanding damage mechanisms, fatigue and fracture, durability and ageing as well as implications for design. The second part of the book covers the modelling of bond performance and failure mechanisms in different loading conditions.