ME221Lecture #301 ME 221 Statics Lecture #30 Sections 6.6 – 6.7 & Exam 3 Review

ME221Lecture #302 Homework #10 Chapter 7 problems: –5, 8, 19, 21, 24, 26 & 35 Due Today

ME221Lecture #303 Homework #11 Chapter 6 problems: –2, 3, 6 & 7 – Method of Joints –32, 36, 47 & 53 – Method of Sections –6.47: E-G should be 0.2m Due Friday, November 22

ME221Lecture #304 Exam #3 Friday, November 15 Details Later

ME221Lecture #305 Trusses Composed of slender straight pieces connected together by frictionless pins where all the loads (no moments) are applied. Each member will act as a two-force member (either in tension or compression). All the forces acting on a truss member are axial.

ME221Lecture #306 Analysis of Trusses Using the Method of Joints AyAy AxAx P Ax P AY P By P Bx P Cy P Cx CyCy A B C  We need to solve for: (1) - Internal forces F AB, F AC, and F CA (2) - Reactions A x, A y and C y

ME221Lecture #307 Using Matrix Notation = Using manual calculations Look for joints with 2 unknowns

ME221Lecture #308 Example 1.2 m 1.2 m 6 kN 3 kN E B A CD 0.9 m

ME221Lecture #309 6 kN 3 kN E B A C D

ME221Lecture # m 12 kN 12 kN 2.4 m=9.6 m B D F H J A C E G I Method of Sectioning If the question is to find internal forces in selected members of the truss, then one can alternatively use the method of sectioning. Example: Determine the force in members FG and FH

ME221Lecture # m 12 kN 12 kN B D F H J A C E G I F GE F GF F HF 1.8 m 12 kN 12 kN B D F H J A C E G I F EG F FG F EH

ME221Lecture #3012 Exam #3 Chapter 9: Moments of Inertia –Second Moment of Area; I xx & I yy –Polar Moments; J 0z –Parallel Axis Theorem –Composite Areas –Principal Second Moments; I xy –Mohr’s Circle

ME221Lecture #3013 Exam #3 Chapter 5: Equilibrium of Rigid Bodies –Equilibrium Equations –Supports –Free Body Diagrams –Two-Force Members –3D Equilibrium

ME221Lecture #3014 Exam #3 Chapter 7: Internal Forces in Structures –Internal Forces –Shear Forces –Bending Moments –Shear & Bending in Beams