# Bending-Stress Essay

1153 Words5 Pages
Bending Stress and its Distribution Induced in a Section Learning Objectives:     To calculate the value of bending stress at a given point in a section To understand the nature of bending stress To understand the distribution of bending stress cross a section To appreciate the way to reduce the bending stress without using more material My  I cz Worked Example: Calculate the Maximum Stresses in the Beam y P=10kN A 2m K B 2m K C 250 c z 60 RAy Rcy Section K-K through Beam Assuming that the beam has a uniform section  Determine the section where maximum bending moment occurs  Work out the stress distribution at the section due to the maximum BM Slide 6 Slide 5 Determine the Location(section) Where the Maximum Bending Moment Occurs  Sketch SF and BM diagrams O P=10kN A 2m B 2m C x Rcy=5kN 5 -5  Locate the section Ray=5kN along the total span of the beam where SF 5 BM takes its O maximum value Gain the value of the maximum banding moment BM x -5 x  10kNm O At section B, BM takes maximum value: M=BM=10kNm Determine both Centroid and Second Moment of Area for Section B K y P=10kN A 2m B 2m K C 250 c z y  125 60 Ray=5  cz Rcy=5 will be neutral axis WHY?  “d” is the side of 250mm  Centroid can be given y  d / 2  250 / 2  125mm  Icz = Igz and can be calculated Section K-K through Beam bd 3 60  2503 =78,125,000 mm4  I cz  12 12 Stress Distribution Cross Section Under the Bending Moment (M=BM=10kNm) y S 3 My  I cz c y z  Direct stress  at position S within the section is resulted from the bending moment M in the section  y is the PERPENDICULAR distance of any position S to the neutral axis within the section  Icz is the second moment of area for the section   is proportional to the distance y Slide 3 Slide 3 Bending Stresses at Three Typical Points within the Section  Stresses at point