ME 221Lecture 211 ME 221 Statics Lecture #21 Sections

ME 221Lecture 212 Homework #7 Chapter 4 problems: –52, 53 & 54 Chapter 9 problems: –2, 3, 4, 11, 23, 29 & 32 –Use double integration for 2, 3, 4 & 11 Due today

ME 221Lecture 213 Homework #8 Chapter 9 problems: –42, 43, 50 & 55 Chapter 5 problems: –11, 13, 16, 20, 24 & 25 –See Blackboard for additional information Due Wednesday, October 30

Exam #2 Results Average score = 81 Scores posted on Blackboard Solution posted on Blackboard See syllabus for regrade policy

Last Lecture Principal Second Moments Product Moment of Inertia Principal Axes Mohr’s Circle

Mechanics Nomenclature Polar Moment of Inertia = Torsional Stiffness Second Moment of Area = Bending Stiffness

ME 221Lecture 217 Product Moment of Inertia Basic section with two axes of symmetry x y Composite sections - product parallel axis theorem

ME 221Lecture 218 Mohr’s Circle for Principal Inertia +I xy -I xy I xx, I yy I yy x I xx I xy x draw point (I xx, I xy ) and the circle (I xx +I yy )/2 draw circle center (I xx + I yy )/2 x I MAX I MIN 22 use geometry to find I MAX, I MIN and  Angles in Mohr’s circle are twice those in the section analyzed.

ME 221Lecture 219 Chapter 9 Examples

Guest Speaker Engineering Study Abroad Program Dr. Darren Mason Albion College (formerly at MSU) Engineering in Russia Summer 2003