Ders Bilgileri

#### Ders Tanımı

Ders Kodu Yarıyıl T+U Saat Kredi AKTS
FAILURE OF ENGINEERING MATERIALS CMM 519 0 3 + 0 3 6
 Dersin Dili Türkçe Dersin Seviyesi Yüksek Lisans Dersin Türü SECMELI Dersin Koordinatörü Dr.Öğr.Üyesi SUNAL AHMET PARASIZ Dersi Verenler Dersin Yardımcıları Dersin Kategorisi Dersin Amacı During design of a component or structure the possibility of failure should be minimized. Thus, for a design engineer it is important to understand the mechanics of the various failure modes?fracture, fatigue, and creep?and be familiar with appropriate design principles that may be employed to prevent failures during service. In this course the aim is to provide some knowledge for students in this perspective. Dersin İçeriği Strain and stress relationships, elastic and inelastic deformation of materials, crystalline structure and defects, elements of fracture mechanics, factors affecting failure, fatigue and creep, and environmental degradation of materials.
 Dersin Öğrenme Çıktıları Öğretim Yöntemleri Ölçme Yöntemleri 1 - Describe dimple-fracture, the cup- and cone fracture, the embrittlement at high deformation rate, large grain sizes and three-axial stress-states 1 - 2 - 3 - 4 - 5 - A - C - 2 - Describe the transition from ductile to brittle fracture for decreasing temperature and increasing grain size 1 - 2 - 3 - 4 - 5 - A - C - 3 - Use fracture criteria according to theoretical strength, Griffith?s theory, fracture mechanics. 1 - 2 - 3 - 4 - 5 - A - C - 4 - Describe the initiation and propagation of fatigue cracks and to predict the number of cycles to failure from information on crack propagation rate, load conditions, initial crack size and fracture toughness, KIC. 1 - 2 - 3 - 4 - 5 - A - C - 5 - Predict the influence of a static load on the fatigue strength of a material according to the Goodman and the Gerber relations. 1 - 2 - 3 - 4 - 5 - A - C - 6 - Knows creep mechanisms: dislocation creep, Nabarro-Herring creep and Coble creep 1 - 2 - 3 - 4 - 5 - A - C - 7 - Use creep deformation mechanism maps. 1 - 2 - 3 - 4 - 5 - A - C - 8 - Knows design criteria?s for prevention for fatigue and creep failure. 1 - 2 - 3 - 5 - A - C -
 Öğretim Yöntemleri: 1:Lecture 2:Question-Answer 3:Discussion 4:Drilland Practice 5:Demonstration Ölçme Yöntemleri: A:Testing C:Homework

#### Ders Akışı

Hafta Konular ÖnHazırlık
1 General concepts of strain and stress. Elastic and inelastic deformation of materials.
2 Crystalline structure, defects and microstructure in solids.
3 Theoretical strength of solids. Stress concentration factor. Ductile and brittle fracture characteristics.
4 Elements of Fracture mechanics. Griffith crack theory, critical flaw size and design philosophy.
5 Determination of toughness from crack opening displacement and J integral tests. Parameters that affect fracture. Notch bar impact testing of materials.
6 Fatigue fracture appearance. Parameters that affect fatigue life.
7 Parameters that affect fatigue life.
8 Design for fatigue. Safe?life and fail-safe approaches.
9 Cyclic softening and hardening.
10 Mid-term exam
11 Homologous temperature. Creep strain and strain-time curves. Creep deformation mechanisms
12 Prediction of creep behavior of materials. Stress relaxation. Super plastic behavior of materials.
13 Materials for elevated temperature applications. Prevention of creep failure.
14 Environmental degradation of materials, hydrogen embrittlement, stress corrosion

#### Kaynaklar

Ders Notu Mechanical Behavior of Materials, Norman E. Dowling, 2012
Ders Kaynakları 1. Fatigue of materials, S. Suresh, 1998
2. Deformation and Fracture Mechanics of Engineering Materials,, R.W.Hertzberg, John Wiley, 1995

#### Dersin Program Çıktılarına Katkısı

No Program Öğrenme Çıktıları KatkıDüzeyi
1 2 3 4 5

#### Değerlendirme Sistemi

YARIYIL İÇİ ÇALIŞMALARI SIRA KATKI YÜZDESİ
AraSinav 1 50
Odev 1 10
Odev 2 10
Odev 3 10
Odev 4 10
Odev 5 10
Toplam 100
Yıliçinin Başarıya Oranı 60
Finalin Başarıya Oranı 40
Toplam 100

#### AKTS - İş Yükü

Etkinlik Sayısı Süresi(Saat) Toplam İş yükü(Saat)
Course Duration (Including the exam week: 16x Total course hours) 16 3 48
Hours for off-the-classroom study (Pre-study, practice) 16 3 48
Mid-terms 1 12 12
Assignment 5 5 25
Final examination 1 12 12
Toplam İş Yükü 145
Toplam İş Yükü /25(s) 5.8
Dersin AKTS Kredisi 5.8
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