Solid Mechanic
Chapter Objectives
To show how to use the method of sections for determining the internal loadings in a member. To introduce the concepts of normal and shear stress. To analyse and design members subject to axial load and direct shear. To define normal and shear strain, and show how they can be determined for various types of problems.
Copyright © 2011 Pearson Education South Asia Pte Ltd
In-Class Activities
• • • • • • • • Reading Quiz Applications Normal Stress Shear Stress Normal Strain Shear Strain Cartesian Strain Components Concept Quiz
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ
1. What is the normal stress in the bar if P=10 kN and 500 mm²?
a) b) c) d) e) 0.02 kPa 20 Pa 20 kPa 200 N/mm² 20 MPa
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
2. What is the average shear stress in the internal vertical surface AB (or CD), if F=20 kN, and AAB=ACD=1000 mm²?
a) b) c) d) e) 20 N/mm² 10 N/mm² 10 kPa 200 kN/m² 20 MPa
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
3. The center portion of the rubber balloon has a diameter of d = 100 mm. If the air pressure within it causes the balloon’s diameter to become d = 125 mm, determine the average normal strain in the rubber.
a) b) c) d) 0.2 0.25 π 0.25 1.25
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
4. What is the unit of strain?
a) b) c) d) mm mm/m Micron no unit
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS
Where does the average normal stress occur?
Copyright © 2011 Pearson Education South Asia Pte Ltd
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS (cont)
Will the total shear force over the anchor length be equal to the total tensile force σtensile A in the bar?
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS
Copyright © 2011 Pearson Education South Asia Pte Ltd
AVERAGE
To show how to use the method of sections for determining the internal loadings in a member. To introduce the concepts of normal and shear stress. To analyse and design members subject to axial load and direct shear. To define normal and shear strain, and show how they can be determined for various types of problems.
Copyright © 2011 Pearson Education South Asia Pte Ltd
In-Class Activities
• • • • • • • • Reading Quiz Applications Normal Stress Shear Stress Normal Strain Shear Strain Cartesian Strain Components Concept Quiz
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ
1. What is the normal stress in the bar if P=10 kN and 500 mm²?
a) b) c) d) e) 0.02 kPa 20 Pa 20 kPa 200 N/mm² 20 MPa
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
2. What is the average shear stress in the internal vertical surface AB (or CD), if F=20 kN, and AAB=ACD=1000 mm²?
a) b) c) d) e) 20 N/mm² 10 N/mm² 10 kPa 200 kN/m² 20 MPa
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
3. The center portion of the rubber balloon has a diameter of d = 100 mm. If the air pressure within it causes the balloon’s diameter to become d = 125 mm, determine the average normal strain in the rubber.
a) b) c) d) 0.2 0.25 π 0.25 1.25
Copyright © 2011 Pearson Education South Asia Pte Ltd
READING QUIZ (cont)
4. What is the unit of strain?
a) b) c) d) mm mm/m Micron no unit
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS
Where does the average normal stress occur?
Copyright © 2011 Pearson Education South Asia Pte Ltd
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS (cont)
Will the total shear force over the anchor length be equal to the total tensile force σtensile A in the bar?
Copyright © 2011 Pearson Education South Asia Pte Ltd
APPLICATIONS
Copyright © 2011 Pearson Education South Asia Pte Ltd
AVERAGE