Download (see graph) distinct yield: Yield strength 66.7 ksi (lower yield 63.8 ksi

ES230 Strength of Materials
Lesson 7: Properties of Materials I
HOMEWORK (SOLUTION)
0. MecMovie M3.1 and M3.2 (do not hand in). Be sure to hit the “continue” button throughout these, as this will show
graphical illustrations as specimens deform, etc.
1. MecMovie M3.3. As with previous MecMovie assignments, simply print out the results page and hand it in.
2. A metal specimen with a diameter of 0.500 inches and a 2.0-inch gage length was tested to fracture, in tension.
Load and deformation data is given below. Graph the stress-strain BY HAND (do not use Excel), using two
different scales (see Philpot Figure P3.16, as an example). Then, determine:
A.
B.
The proportional limit: 56.3
ksi (see graph)
The modulus of elasticity (if the data is “noisy”, use a best-fit until the proportional limit): 30,450ksi
(see graph)
C.
D.
The ultimate strength: 97.3
ksi (see graph)
If the specimen had a distinct yield, locate this value on the graph and report it. If the specimen did not
The specimen had a
distinct yield: Yield strength 66.7 ksi (lower yield 63.8 ksi)
have a distinct yield, determine the yield strength using 0.2% offset.
E. The fracture stress: 81.0 ksi (see graph)
F. The true fracture stress if the final diameter at the location of the fracture was 0.387 inches: 135
Load
lbs
0
2690
5670
8360
11050
12540
13150
13140
12530
12540
12840
12840
12540
12540
14930
17020
18220
18820
19110
19110
18520
17620
16730
16130
15900
Delta
inches
0
0.0009
0.0018
0.0028
0.0037
0.0042
0.0046
0.006
0.0079
0.0098
0.0121
0.0139
0.0209
0.0255
0.0487
0.0835
0.1252
0.1809
0.2551
0.2968
0.3107
0.3246
0.3339
0.3385
Bang

psi
0
13700
28877
42577
56277
63866
66972
66921
63815
63866
65394
65394
63866
63866
76038
86682
92794
95849
97326
97326
94322
89738
85205
82149
80978

in/in
0.00000
0.00045
0.00090
0.00140
0.00185
0.00210
0.00230
0.00300
0.00395
0.00490
0.00605
0.00695
0.01045
0.01275
0.02435
0.04175
0.06260
0.09045
0.12755
0.14840
0.15535
0.16230
0.16695
0.16925
ksi
ES230 Strength of Materials
Lesson 7: Properties of Materials I
ES230 Strength of Materials
Lesson 7: Properties of Materials I
ES230 Strength of Materials
5.
Lesson 7: Properties of Materials I
A steel member with a cross-sectional area of 1.5 in2 is 25-feet long and is made from the same material tested in the
previous problems. If the steel member was subjected to a force of 135 kips, determine the length of the member
when the 135 kips is applied. Then, determine the length of the member after the 135 kips is removed.