6. A drone motor can apply a maximum torque of T = 2.1 N. m. At the start of the rotation, the propeller gets stuck and cannot spin, additionally causing a maximum bending moment of M = 1.0 N. m. The motor shaft is made of a hardened tool steel with a diameter of d = 1.5 mm and mechanical properties of E = 210 GPa, v = 0.32, K₁ = 42 MPa√√m and σ = 5.2 GPa. A small scratch of depth a is made on the surface of the shaft. a. What are the principle stresses in the shaft? b. If we assume the shaft fails in a brittle manner, will the shaft fail? c. How deep can the scratch be if we want a fracture factor of safety of X- = 2? Assume the worst- case crack is oriented orthogonal to the max principal stress (σ₁) and the concentration factor is Y = 1.12. wwwwww M T d Surface Scratch
6. A drone motor can apply a maximum torque of T = 2.1 N. m. At the start of the rotation, the propeller gets stuck and cannot spin, additionally causing a maximum bending moment of M = 1.0 N. m. The motor shaft is made of a hardened tool steel with a diameter of d = 1.5 mm and mechanical properties of E = 210 GPa, v = 0.32, K₁ = 42 MPa√√m and σ = 5.2 GPa. A small scratch of depth a is made on the surface of the shaft. a. What are the principle stresses in the shaft? b. If we assume the shaft fails in a brittle manner, will the shaft fail? c. How deep can the scratch be if we want a fracture factor of safety of X- = 2? Assume the worst- case crack is oriented orthogonal to the max principal stress (σ₁) and the concentration factor is Y = 1.12. wwwwww M T d Surface Scratch
Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
Related questions
Question
![6. A drone motor can apply a maximum torque of T = 2.1 N. m. At the start of the rotation, the propeller
gets stuck and cannot spin, additionally causing a maximum bending moment of M = 1.0 N. m. The
motor shaft is made of a hardened tool steel with a diameter of d = 1.5 mm and mechanical properties
of E = 210 GPa, v = 0.32, K₁ = 42 MPa√√m and σ = 5.2 GPa. A small scratch of depth a is made
on the surface of the shaft.
a. What are the principle stresses in the shaft?
b. If we assume the shaft fails in a brittle manner, will the shaft fail?
c. How deep can the scratch be if we want a fracture factor of safety of X- = 2? Assume the worst-
case crack is oriented orthogonal to the max principal stress (σ₁) and the concentration factor is
Y = 1.12.
wwwwww
M
T
d
Surface
Scratch](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F1720cd77-2294-45a6-8b70-43447dc02920%2F938ffe4d-7c6e-4c06-92ed-dea9fe8e2743%2Fvndqc69_processed.png&w=3840&q=75)
Transcribed Image Text:6. A drone motor can apply a maximum torque of T = 2.1 N. m. At the start of the rotation, the propeller
gets stuck and cannot spin, additionally causing a maximum bending moment of M = 1.0 N. m. The
motor shaft is made of a hardened tool steel with a diameter of d = 1.5 mm and mechanical properties
of E = 210 GPa, v = 0.32, K₁ = 42 MPa√√m and σ = 5.2 GPa. A small scratch of depth a is made
on the surface of the shaft.
a. What are the principle stresses in the shaft?
b. If we assume the shaft fails in a brittle manner, will the shaft fail?
c. How deep can the scratch be if we want a fracture factor of safety of X- = 2? Assume the worst-
case crack is oriented orthogonal to the max principal stress (σ₁) and the concentration factor is
Y = 1.12.
wwwwww
M
T
d
Surface
Scratch
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Recommended textbooks for you
![Elements Of Electromagnetics](https://www.bartleby.com/isbn_cover_images/9780190698614/9780190698614_smallCoverImage.gif)
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
![Mechanics of Materials (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134319650/9780134319650_smallCoverImage.gif)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Thermodynamics: An Engineering Approach](https://www.bartleby.com/isbn_cover_images/9781259822674/9781259822674_smallCoverImage.gif)
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
![Elements Of Electromagnetics](https://www.bartleby.com/isbn_cover_images/9780190698614/9780190698614_smallCoverImage.gif)
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
![Mechanics of Materials (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134319650/9780134319650_smallCoverImage.gif)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Thermodynamics: An Engineering Approach](https://www.bartleby.com/isbn_cover_images/9781259822674/9781259822674_smallCoverImage.gif)
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
![Control Systems Engineering](https://www.bartleby.com/isbn_cover_images/9781118170519/9781118170519_smallCoverImage.gif)
Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY
![Mechanics of Materials (MindTap Course List)](https://www.bartleby.com/isbn_cover_images/9781337093347/9781337093347_smallCoverImage.gif)
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning
![Engineering Mechanics: Statics](https://www.bartleby.com/isbn_cover_images/9781118807330/9781118807330_smallCoverImage.gif)
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY