Lab #4 Report due TODAY Individual Data Processing and
Individual Write Up Lab #4 Report is due TODAY by
midnight Answer Multiple Choice Questions
ONLINE TODAY Answer Student Survey ONLINE TODAY Submit the Lab Report #4 in the drawer
labeled “Strength of Materials I Lab” beneath M. E. Mail Folders
Theory of Pure Elastic Bending Four Point Bending Configuration Shear Force and Bending Moment
Diagrams Stresses and Deformations in Pure
Bending Sagital Method to find Radius of
Curvature Determine Elastic Modulus of material Comparison to handbook value and
previous Lab #4 result
Four Point Bending Setup
Shear Force & Bending Moment Diagrams
R1 = R2 = F
V = 0 in middle span
M = -bF = constantin middle spanPure
Bending
Pure BendingMaterial Assumptions Homogeneous Isotropic
Geometry/Load Assumptions
X-section has a plane of symmetry
Bending moment applied in that plane
Deformation Grids
Neutral Axis and Strain(elastic and plastic range)
Elastic Strain & Stress Distribution
=1𝜌
=𝑀𝐸𝐼
x = -y/ x = Ex = -Ey/
𝐼=𝑤𝑡3
12
Sagital Method to find theRadius of Curvature
h × (2 - h) = a2
2h – h2 = a2
If h << and a then
M = bF
Shear Force & Bending Moment Diagrams
R1 = R2 = F
V = 0 in middle span
M = -bF = constantin middle spanPure
Bending
Data Sheet
Processing Data
h=[𝑧 2− 𝑧1+𝑧 32 ]
25.4𝜌=𝑎2+h2
2h
𝐼=𝑤𝑡3
12
Plotting Multiple Lines
Adding Data for another Line
h versus W Line Fits
h=𝑏𝐹𝑎2
2𝐸𝐼
Fitting Straight Line
LINEST function (y = m*x + b) Gradient m = INDEX( LINEST(y-values, x-values, False, True), 1)
Coefficient r2 =INDEX( LINEST(y-values, x-values, False, True), 3)
b = 0
b = 0
r2
m
Table of a2 and gradients
𝑔𝑟𝑎𝑑𝑖𝑒𝑛𝑡= 𝑏𝑎2
2𝐸𝐼
Plot of Gradient versus a2
𝑔𝑟𝑎𝑑𝑖𝑒𝑛𝑡= 𝑏𝑎2
2𝐸𝐼
Calculating Elastic Modulus E
𝑠𝑙𝑜𝑝𝑒=𝑏2𝐸𝐼
Materials Properties Tables
Fit the spreadsheet on 2 pages
Lab #4 Report due TODAY Individual Data Processing and
Individual Write Up Lab #4 Report is due TODAY by
midnight Answer Multiple Choice Questions
ONLINE TODAY Answer Student Survey ONLINE TODAY Submit the Lab Report #4 in the drawer
labeled “Strength of Materials I Lab” beneath M. E. Mail Folders
