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Ditemukan 24 dokumen yang sesuai dengan query
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Creep of Engineering Materials and of the earth
London: The Royal Society, 1978
551.307 CRE
Buku Teks  Universitas Indonesia Library
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Kraus, Harry
Creep analysis / Harry Kraus
New York: John Wiley, 1980
620.112 3 KRA c (1)
Buku Teks  Universitas Indonesia Library
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Kraus, Harry
Creep analysis / Harry Kraus
New York: John Wiley, 1980
620.112 3 KRA c (1);620.112 3 KRA c (2)
Buku Teks SO  Universitas Indonesia Library
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Recent advances in creep and fracture of engineering materials and structures
Swansea, U.K.: Pineridge Press, 1982
620.11 REC
Buku Teks SO  Universitas Indonesia Library
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Ariyana Dwiputra Nugraha
Kajian pengaruh oksidasi terhadap perilaku creep material tube SA 213 TP 304H = Study effect of oxidation on the creep behavior of the material tube SA 213 TP 304 H / Ariyana Dwiputra Nugraha
"ABSTRAK
Material tube yang dioperasikan pada temperatur tinggi, cepat atau lambat akan
mengalami suatu kerusakan akibat pengaruh temperatur yang dikombinasikan
dengan lingkungan korosif, tekanan & tegangan, baik statis maupun dinamis.
Tube boiler yang mengalami indikasi kegagalan yaitu tube dengan material
SA213 TP304H dengan unsur dominan paduan adalah Cr dan Ni. Material dengan
spesifikasi tersebut merupakan material stainless steel yang seharusnya tahan
terhadap korosi, sehingga dianggap perlu dilakukan pengujian dan penelitian guna
menjawab kecurigaan adanya indikasi kegagalan. Metodologi analisa dan
identifikasi yang dilakukan adalah dengan uji merusak yaitu uji spectrometer,
metalografi dan 3D metalografi, SEM dan EDX, kekerasan, serta creep rupture
dengan parameter Larson Miller. Hasil penelitian menunjukan bahwa tube telah
mengalami korosi oksidasi yang cukup parah dan telah terjadi penjalaran
intergranular crack pada material, sehingga ketebalan tube yang tersisa hanya 65
% dari ketebalan total. Unsur dominan pembentuk oksida dan karbida pada
material yaitu oksida Fe (FeO, Fe2O3, dan Fe3O4) dan karbida (Fe, Cr, Ni,
Mn)23C6 atau M23C6. Long-term creep strengh berkurang drastis pada temperatur
650 0C dengan persamaan LMP material adalah 17,239 = T (15 + log tr) 10-3.
ABSTRACT
Material tube operated at high temperatures, sooner or later will suffer damages
due to the influence of temperature combined with a corrosive environment,
pressure and tension, both static and dynamic. Indication of failure in boiler tube
was observed in material tube SA213 TP304H with the dominant element is Cr
and Ni alloys. Materials with these specifications classified as stainless steel
material that should be resistant to corrosion, so it is considered necessary to test
and analize in order to answer suspicions of failure. Methodology for the analysis
and identification is done by destructive test that is spectrometer test,
metallographic and 3D metallography, SEM and EDX, hardness, and creep
rupture with Larson Miller parameter. The results showed that the tube has
experienced severe corrosion and oxidation and also has occurred intergranular
crack propagation in the material, so that the thickness of the tube is decreased to
65% only from total thickness. The dominant element forming the oxide and
carbide materials are iron oxide (FeO, Fe2O3, and Fe3O4) and carbide (Fe, Cr, Ni,
Mn)23C6 or M23C6. Long-term creep strengh is reduced drastically at temperatures
of 650 0C with LMP material equation is 17.239 = T (15 + log tr) 10-3."
2016
T46750
UI - Tesis Membership  Universitas Indonesia Library
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L.T. Erick Erland M.
Dinamika bubble pada aliran creep
"Dalam penelitian ini gelembung udara yang mengalir parla aliran creep dan perilakunya diamati. Sebuah water loop terbuka digunakan untuk meneliti ape yang terjadi pada gelembung didalam aliran creep. Test cell berupe pipe acrylic dengan diameter dalam 4 mm dan panjang 50 mm digunakan untuk meneliti perilaku gelembung tersebut. Penelitian ini mernperlihatkan bahwa kecepatan gelembang dipengaruhi oleh dinding pembatas aliran dan diameter gelembung Dengan bertambahnya ukuran gelembung kecepetan gelembung menurun. Perubahan bentuk gelembung tidak teramati dikarenakan diameter gelembung yang
Air bubble flows in creep flow and its behavior are studied in this experiment. An acrylic pipe test cell, 4 mm diameter and 50 mm length, in an open waler loop constructed to Jearn the behavior. The study shows that pipe wall and bubble diameter ajfocted its velocity, increased diameter decreasing bubble velocity. While shape changes unable to studied since bubble diameter too small."
Depok: Fakultas Teknik Universitas Indonesia, 2006
S37541
UI - Skripsi Membership  Universitas Indonesia Library
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Indra Chusaini San
Dinding penahan tahanan lapangan parkir dermaga pengumbuk permasalahan dan penanggulangan
"The construction of the retaining wall should be base on stability calculation and safety factor, because any error in the construction process can have fatal consequences in property damages and the lost of life. The case of retaining wall at Lapangan Parkir Dermaga Pengumbuk is the damage of its retaining wall, which can be observe by the movement of the retaining wall in horizontal direction and the cracks on the retaining wall. Analysis indicate that the retaining wall failure on this case is due to shear instability, and the creep also contributed to the construction movement on the location. This paper contains the analysis of the problems on the retaining to have an effective and efficient alternative problem solutions."
Palembang: Program studi magister Teknik Siping Univ.Sriwijaya, 2006
624 CAN 1 (1-2) 2006
Artikel Jurnal  Universitas Indonesia Library
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Rani Desiassyifayanty
Calibration of coupling between local damage and creep model with size effect test on concrete beams
"
ABSTRACT
The aim of this research is to reproduce the experimental result using finite element approach with damage model coupled to creep. The calibration of coupling between creep and local damage model associated with size effect law proposed by Bazant are presented in this thesis. Its behavior was investigated through two kinds of studies, the loading rate effect and residual capacity test. Three different sizes of beam, which are geometrically similar specimens, were simulated in three point bending test and creep test divided into load level test and residual capacity test. Numerical simulation was doneusing existing finite element code Aster_ Code developed by EDF (Eiectricite de France) for coupling between local damage based on bi-linear elasto-damage model and creep based on Benboudjema theory. Result show that the finite element code is capable to reproduce the experimental result qualitatively. The interaction between creep and local damage is shown through size effect plot by giving the behavior shift to the right, which means that the materials become more brittle when creep appears.

"
2006
T-Pdf
UI - Tesis Membership  Universitas Indonesia Library
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Ali Arman
Sifat-sifat viskoelastik polyethylene densitas tinggi
"ABSTRAK
Telah dilakukan pengujian sifat-sifat viskoelastik dari Polyethylene Densitas Tinggi (High Density Polyethylene atau HDPE) dengan menggunakan uji creep dan uji relaksasi tegangan. Besarnya beban yang diberikan dalam uji creep adalah dari 100 N sampai 350 N dengan interval 50 N. Untuk mencapai beban konstan digunakan kecepatan regangan 50 mm/min dan 5 mm/min. Regangan konstan yang digunakan dalam uji relaksasi tegangan adalah 1,25%, 2,5%, 3,75%, 5%, 6,25% dan 7,5%. Regangan konstan ini dicapai dengan menggunakan kecepatan regangan 50 mm/min dan 5 mm/min. Pengujian dilakukan selama 30 menit untuk setiap uji creep dan uji relaksasi tegangan. Uji creep juga dilakukan dengan uji makroindentasi. Pengujian ini memakai bola baja dengan diameter 7,93, 11,08, 25,4 dan 44,43 mm, dan beban yang diberikan adalah 4,434, 6,434, 8,434, 10,434 dan 12,434 kg. Setiap pengujian dilakukan selama 2 jam.
Data setiap pengujian dianalisa menggunakan model yang merupakan kombinasi dari pegas (spring) dan peredam (dashpot). Uji creep menggunakan model empat elemen yang menghasilkan empat konstanta yaitu konstanta elastik El dan E2 dan konstanta viskos n1 dan n2 . Relaksasi tegangan memakai model tiga elemen yang menghasilkan tiga konstanta yaitu konstanta elastik El dan E2 dan konstanta viskos n1.
Pada uji creep, seluruh konstanta mempunyai nilai yang meningkat dengan kecepatan regangan yang meningkat, kecuali konstan viskos n2 . Pengaruh dari pemberian beban konstan adalah dengan pertambahan beban konstan maka semua konstanta mempunyai nilai yang meningkat. Sedang uji relaksasi tegangan memiliki nilai konstanta yang berbanding terbalik dengan uji creep. Pengujian dengan makroindentasi menghasilkan efek dari diameter bola yaitu dengan makin besar diameter diperoleh makin besar nilai konstanta elastik. Sedang efek dari pemberian beban yaitu dengan makin besar beban diperoleh makin besar nilai konstanta viskos.
The tests of the viscoelastic properties of High Density Polyethylene (HDPE) has been done which was using creep and stress relaxation tests. The constant loads that are applied for creep test are 100N to 350N steps 50N. In order to get the constant loads, it was used different of strain rate; 50mm/min and 5mm/min. The stress relaxation test was done in different constant strains and the constant strains are from 1.25% to 7.5% step 1.25%. Similar to creep test, the constants strain are reached using strain rate 50mm/min and 5mm/min. Every sample of creep and stress relaxation was tested and hold for 30 minutes. The other creep test is macroindentation test which used ball indenter with 7.93, 11.08, 25.4, and 44.43mm in diameters and 4.434, 6.434, 8.434, 10.434, and 12.434 kg in constant loads.
The data were analyzed using standard linear viscoelastic solid model. The creep test was using four elements model which have two elastic constants El, E2, and two viscous constants n1, n2. While stress relaxation test was using three elements model, which have two elastic constants and one viscous constant.
The result of the tests are, the strain rate affect both of elastics and viscous constants. All the constants in the creep test increase as the strain rate increase except the viscous constant n2. The effect of constant loads is as the load increase, the constant elastics and viscous decrease. On the other hand, in the stress relaxation test has contrary effect with the creep test. In the macroindentation test, as the diameter increase, the elastic constants increase. More over, as the load increase, the viscous constants increase.
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1999
T-Pdf
UI - Tesis Membership  Universitas Indonesia Library
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Gadang Priyotomo
Korosi Retak Tegang Material Stainless Steel AISI 304 di Lingkungan MgCl2
"Baja tahan karat jenis austenitik AISI 304 mempunyai kerentanan terhadap korosi retak tegang di dalam larutan korosif klorida. Baja tipe ini juga rentan terhadap temperatur sensitasi antara 580°C - 815°C. Kerentanan tersebut jelas terjadi pada korosi batas butir. Batas butir mengandung krom karbida. Kombinasi antara internal material logam dan lingkungan memberikan efek korosi retak tegang. Lingkungan MgCl2 merupakan lingkungan korosif yang berperan dalam jenis korosi ini. Pengujian korosi retak tegang dilakukan dengan metode beban konstan (creep) melalui beban 20 kg/mm2, 25 kg/mm2, 30,5 Kg/mm2, dan 40 Kg/mm2 di larutan 42wt% MgCl2 bersuhu 106°C. Perlakuan material dibagi dua yaitu anil 1100°C, tahan 1 jam, kemudian celup cepat air dan tanpa anil. Kedua perlakuan tersebut disensitasi (600°C,700°C,800°C). Pengujian kualitatif karbida, pengujian komposisi bulk, larutan uji (AAS), pengujian kekerasan Vickers, metalografi (foto makro) dan pengujian SEM EDS dilakukan. Hasil menunjukkan pengujian kekerasan vickers pada suhu sensitasi 7000C mengalami penurunan berkisar 152,06 Hv (anil 1100°C) dan 199,1 Hv (non anil 1100°C) dibandingkan suhu sensitasi 600°C dan 800°C. Tren sama juga terjadi pada pengujian SCC beban konstan, pada temperatur sensitasi 700°C, waktu patah (tf) lebih pendek dibandingkan suhu sensitasi 600°C & 800°C di dua kondisi material berbeda. Waktu patah tercepat pada beban 25 Kg/mm2 3 detik di kondisi anil 1100°C,suhu sensitasi 700°C dan terlama pada beban 30,5 Kg/mm2 86400 detik di kondisi tanpa anil,suhu sensitasi 6000C. Laju pemuluran (iss) tertinggi pada beban 25 kg/mm2 4,80 mm/detik di kondisi anil 11000C,suhu sensitasi 700°C dan terendah pada beban 30,5 Kg/mm2 3.10-8 mm/detik di kondisi tidak anil 1100°C. Bentuk patahan SCC berbentuk intergranular (tidak dianil 11000C). Bentuk patahan transgranular dengan banyak struktur dimple (void-void) nampak banyak di material anil 1100 berbagai suhu sensitasi. Prosentase peningkatan kelarutan Fe kedalam larutan uji antara 484% hingga 2050% , Kation Cr antara 750% hingga 3540%, dan Kation Ni hingga 110%.
Austenitic Stainless steel (AISI 304) has a susceptibility of stress corrosion cracking inside corrosive chloride solution. This material also is susceptible from sensitizing temperature (580°C-815°C). This susceptibility of material clearly is undergone in intergranular corrosion. Grain boundaries contain chromium carbide. The combination of internal material and environment can contribute a great effect of stress corrosion cracking (SCC). MgCl2 circumstance have main role for SCC as corrosive solution. SCC test was conducted with constant load method (creep) of 20 Kg/mm2, 25 Kg/mm2, 30,5 Kg/mm2, and 40 Kg/mm2 in 42 wt% MgCl2 solution and constant temperature of 1060C. Material treatment is divided two sides : (1) annealing process (1100°C); holding 1 hour then quenching process and (2) without annealing. These two treatments were sensitized at 600°C, 700°C and 800°C. The qualitative test of carbide, the test of bulk chemical composition, solution test (AAS), Vickers hardness test, metallography, and SEM EDS test conducted. Test results show Vickers hardness value on sensitizing temperature of 7000C that was undergone the decreasing of range 152,06 Hv (annealing of 11000C) and 199,1 Hv (non annealing) by comparing sensitizing temperature of 600°C and 800°C. The same trend also was happen at the test of SCC. On sensitizing temperature of 7000C fracture time (tf) is shorter than sensitizing temperature of 600°C and 800°C in two different material conditions. The shortest fracture time is happened at load of 25 Kg/mm2 that is tf of 3 seconds in annealing condition of 1100°C and sensitizing temperature of 700°C. The longest fracture time is also happened at load of 30,5 Kg/mm2 that is tf of 86400 seconds without annealing process and sensitizing 600°C. The Highest Elongation rate (iss) at load of 25 Kg/mm2 is 4,80 mm/s in annealing condition of 1100°C for sensitizing temperature of 700°C. The lowest one at load of 30,5 Kg/mm2 is 3.10-8 mm/s without annealing condition of 1100°C. The average shape of fracture of SCC is intergranular form without annealing process of 11000C. The shape of transgranular fracture with surface structure of dimples was undergone at annealing material of 1100°C with various sensitizing temperatures. The increasing of dissolution percentage of Fe ions to test solution between 484% to 2050%, from 750% to 3540% (Cr ion), and up to 110% (Ni ion)."
Depok: Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2008
T21374
UI - Tesis Open  Universitas Indonesia Library
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