ME306_SP10_Midterm_practice_SOLUTIONS

# ME306_SP10_Midterm_practice_SOLUTIONS - ME306 Mechanics of...

This preview shows pages 1–2. Sign up to view the full content.

ME306 Mechanics of Materials Spring 2009-2010, Lec 002 Midterm Exam– PRACTICE Instructions: Please write legibly and present well organized, logical solutions. ALL FINAL ANSWERS MUST BE EXPRESSED WITH APPROPRIATE UNITS where applicable. Problem 1: (30 points) (a) Explain why a wide flange beam has a greater resistance to bending as compared with a rectangular beam having an equivalent cross sectional area. Provide a sketch and/or equations to support your answer. The resistance to bending will scale with the inverse of the section modulus, defined as the second moment of inertia, I, divided by the largest distance from the neutral surface, c. This may be quantified by noting that in the linear elastic regime, σ ൌ EԖ . So a lower stress corresponds to lower strain due to an applied bending load. Then as S increases, stress and strain will decrease. Comparing a rectangular and W-beam, both having a cross sectional area of 10,200 mm 2 , S rectangular = 34.7 x 10 6 mm 4 (assuming b = h/4) and S W = 126 x 10 6 mm (for a W250 x 80 beam).

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern