1 Jiangyu Li, University of Washington Lecture 18 Fatigue Mechanical Behavior of Materials Sec. 9.6-9.7 Jiangyu Li University of Washington Mechanics of.

Slides:



Advertisements
Similar presentations
ME 271 STRENGTH OF MATERIALS
Advertisements

Design of Machine Elements
CHAPTER 7 Fatigue Failure Resulting from Variable Loading
Fatigue Failure Resulting from Variable Loading
Section VI Shaft Design.
Chapter Outline Shigley’s Mechanical Engineering Design.
ME 388 – Applied Instrumentation Laboratory Fatigue Lab.
Chapter 18 Shafts and Axles Dr. A. Aziz Bazoune
Strength of Material-5 Torsion Dr. Attaullah Shah.
Design of Machine Elements
Over the Next Several Days
Chapter 18 Shafts and Axles Dr. A. Aziz Bazoune
DESIGNING AGAINST FATIGUE
Jiangyu Li, University of Washington Lecture 21 Fracture Mechanics Mechanical Behavior of Materials Section Jiangyu Li University of Washington.
FATIGUE TEST EXPERIMENT # 5 Instructor: M.Yaqub. FATIGUE.
Unit 3: Solid mechanics An Introduction to Mechanical Engineering: Part Two Solid mechanics Learning summary By the end of this chapter you should have.
Jiangyu Li, University of Washington Lecture 16 Torsion Mechanical Behavior of Materials Section Discussion on the torsion test posted online.
THEORIES OF FAILURE THEORIES OF FAILURE FOR DUCTILE MATERIALS
Section VI Shaft Design.
Chapter 6 Fatigue Failure Theories
© 2011 Autodesk Freely licensed for use by educational institutions. Reuse and changes require a note indicating that content has been modified from the.
PROBLEM-1 State of stress at a point is represented by the element shown. Determine the state of stress at the point on another element orientated 30
Chapter 5, Part B Failure Modes
PROBLEM mm x y 800 mm P = 1500 N z y 50 mm 100 mm
Chapter 7 Fatigue Failure Resulting from Variable Loading
Chapter 7 Fatigue Failure Resulting from Variable Loading
Chapter 7 Fatigue Failure Resulting from Variable Loading
Design Stress & Fatigue
DESIGN FOR FATIGUE STRENGTH
Chapter 7 Fatigue Failure Resulting from Variable Loading
Mechanics of Materials Lab
FATIGUE Fatigue of Materials (Cambridge Solid State Science Series) S. Suresh Cambridge University Press, Cambridge (1998)
Fatigue Failure Due to Variable Loading
1 Design for Different Type of Loading Lecture Notes Dr. Rakhmad Arief Siregar Kolej Universiti Kejuruteraan Utara Malaysia Machine Element in Mechanical.
Failure Criteria and stress concentration
Chapter 7 Fatigue Failure Resulting from Variable Loading
MECH 401 Mechanical Design Applications Dr. M. O’Malley– Master Notes
Ch 7 Shafts.
Machine Design I (MCE-C 203) Mechatronics Dept., Faculty of Engineering, Fayoum University Dr. Ahmed Salah Abou Taleb Lecturer, Mechanical Engineering.
1 INTRODUCTION TO DESIGN SKMM 1512 Semester 2 Session 2014/2015.
Jiangyu Li, University of Washington Yielding and Failure Criteria Plasticity Fracture Fatigue Jiangyu Li University of Washington Mechanics of Materials.
Course No.: MEBF ZC342 MACHINE DESIGN
Unit-5. Torsion in Shafts and Buckling of Axially Loaded Columns Lecture Number-3 Mr. M.A.Mohite Mechanical Engineering S.I.T., Lonavala.
ENT 353 Advanced Mechanical Design Dr. Haftirman /Shah Fenner Khan/Ahmad Yusri 1 ENT 353 ADVANCED MECHANICAL DESIGN Lecture 2. Fatigue of Metals 16/07/2007.
1 Jiangyu Li, University of Washington Lecture 15 Fatigue Mechanical Behavior of Materials Sec Jiangyu Li University of Washington Mechanics.
EGM 5653 Advanced Mechanics of Materials
153 書名: Essentials of Mechanical Engineering Design, 1/E 作者: Shigey Mischke Budynas 書號: MX0398.
Hasmukh Goswami College Of Engineering
FATIGUE TESTING Presented by- BIPIN KUMAR MISHRA 2011EME11 SHEELOO SINGH 2011EME08.
DESIGN OF MACHINE ELEMENTS
FLUCTUATING STRESSES SUBJECT: Design of machine elements
Muhannad Al_Waily_Machines Systems Design
Machine Design: An Overview
MECH 401 Mechanical Design Applications Dr. M. O’Malley– Master Notes
Stress Concentration Effect
Design of Shaft References:
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Mechanics of Materials Lab
Lecture 5: Fully-Reversing Fatigue and the S-N Diagram
Lab8: Fatigue Testing Machine
Yielding And Fracture Under Combine Stresses
Presentation transcript:

1 Jiangyu Li, University of Washington Lecture 18 Fatigue Mechanical Behavior of Materials Sec Jiangyu Li University of Washington Mechanics of Materials Lab

2 Jiangyu Li, University of Washington S-N Diagram

3 Jiangyu Li, University of Washington S-N Diagram Endurance limit

4 Jiangyu Li, University of Washington Endurance Limit For steel

5 Jiangyu Li, University of Washington Fatigue Failure Criteria

6 Jiangyu Li, University of Washington Effect of Mean Stress

7 Jiangyu Li, University of Washington Effect of Mean Stress

8 Jiangyu Li, University of Washington Fatigue Failure Criteria Multiply the stress By safety factor n

9 Jiangyu Li, University of Washington Example: Gerber Line AISI 1050 cold-drawn bar, withstand a fluctuating axial load varying from 0 to16 kip. Kf=1.85; Find Sa and Sm and the safety factor using Gerber relation Sut=100kpsi; Sy=84kpsi; Se’=0.504Sut kpsi Change over Table

10 Jiangyu Li, University of Washington Example: ASME Elliptic Table

11 Jiangyu Li, University of Washington Example AISI 4340 steel is subjected to cyclic load with a tensile mean stress of 200 MPA –What is the fatigue life for stress amplitude of 450 MPA –Estimate the relationship between stress amplitude and fatigue life for this mean stress

12 Jiangyu Li, University of Washington Safety Factor with Mean Stress

13 Jiangyu Li, University of Washington Example Man-Ten steel subject to stress amplitude of 180 Mpa and mean stress of 100PMa for cycles –What is the safety factor in life and stress?

14 Jiangyu Li, University of Washington Torsional Fatigue Strength

15 Jiangyu Li, University of Washington Combination of Loads Use Se from bending; Apply appropriate Kf for each mode; Multiply axial stress component by 1/kc Find the principle stresses Find von Mises effective alternative stress Use the fatigue failure criteria to determine safety factor

16 Jiangyu Li, University of Washington A rotating AISI 1018 cold-drawn steel tube (42x4 mm) has a 6mm diameter hole drilled transversely through it. The shaft is subjected to a torque Fluctuating from 20Nm to 160Nm, and a stead bending moment 150Nm Estimate safety factor Sut=440 Mpa, Syt=370MPa, Se’=0.504x440 =222 Mpa, Se=166MPa Stress concentration factor Kt=2.366, from Table A-16, for bending, Kts=1.75 for torsion; from the Fig. 7-20, 7-21, notch sensitivity q is 0.78 for bending, and 0.96 for torsion. Thus Kf=2.07 for bending, and Kfs=1.72 for torsion Example

17 Jiangyu Li, University of Washington Example Tm=(20+160)/2=90Nm; Ta=(160-20)/2=70Nm

18 Jiangyu Li, University of Washington Assignment Mechanical Behavior of Materials 9.30, 9.31,9.33, 9.35