TECH 3513 Material Tests and Analysis
CHAPTER 7 HOMEWORK
7.49 The area under each curve in Figure 7.11 on page 179 is estimated by adding the areas under the initial elastic region and the flat regions under the curve. This area under the curve is toughness. The data is given in the table below. Plot the graph of the Toughness (y axis) versus Temperature (x axis) (plot the points and then draw a curve through the points). Use the scale from -40 to 100 by 20 on the x-axis and use the scale 100 to 800 by 100 on the y-axis.
Temperature (oC) Toughness (Mj/m3)
7.51 Use the materials shown in the table below. The formula for maximum deflection (d) of a cantilevered beam is d = P * L3 / (3 * E * I), where P is the load (50 kg = 490 N, use P = 490 N), L is the beam length (L = 1 m), E is the elastic modulus, and I is the moment of inertia (I = b*h3/12, where b = 0.02 m and h = 0.075 m, so I = 7.03 x 10-7). Calculate the maximum deflection. ANSWER IN METERS.
Material Elastic Modulus (E) (Pa)
ABS 2.1 x 109
Acetal 2.45 x 109
Epoxy 10.25 x 109
ABS, reinforced 7.5 x 109
Acetal, reinforced 10 x 109
Epoxy, reinforced 36.5 x 109
Aluminum 70 x 109
Steel 195 x 109
Note: The results show that ABS has the most deflection and steel the least.
7.53 Use the table of values below. The formula for required weight (N) is W = p * g * F * L / σy where p is the density, g is the gravitational constant (9.81 m/s2), F = 5000 N, L = 1 m, and σy is the UTS. Calculate the required weight. ANSWER IN KILOGRAMS.
Material Density (p) (kg/m3) UTS (σy) (N/m2)
HMW polyethylene 950 2.4 x 107
Polyester 1270 5 x 107
Rigid PVC 1400 4.1 x 107
ABS 1030 3 x 107
Polystyrene 1000 3.2 x 107
Reinforced nylon 1130 9 x 107
this is the number of the book
- Kalpakjian & Schmid (2014), Manufacturing Engineering and Technology, 7th Edition, Pearson Education, Inc.
- ISBN-13: 978-0-13-312874-1