CIV100H1 Lecture Notes - Lecture 31: Centroid
Document Summary
Civ100 lecture 31 parallel axis theorem. This theorem refers to the second moment of area about another axis parallel to the centroid axis. 3 parts to this theorem: stress bending = m*y / i. I = 2nd moment of area about centroid axis: irectangle with length b , iv-v = i centroidal axis + at2. = bd3 / 12 about centroidal axis of rectangle. Iv-v = y 2da = = y 2bdy = b[y3/3] d. Iv-v = icentroidal axis + at2 = (bd3/ 12 ) + (bd * (d/22)) = b( (d3/12) + (d3 /4) ) = bd3/3. Icross-section about x-axis = {[( (200 * 202 ) / 12) + ( 200 * 20 * 202) ] * 2} + ((10 * 4003)/12) + (400*10*t)2 = bd3 / 12 = 4064 * 106 mm4. Example 3 on asymmetrical sections eam bends about the x-x axis and passes thrgouh the centroid g.
