A structural support for a machine is subjected to a static compression load of 20 kN. The support is manufactured from a circular rod made from SAE 1040 Hot Rolled steel. Specify suitable diameter for the cross section of the rod based on the basic size. Steel data are available in Table A-10 from the textbook. A-10 Typical propertics of carbon and alloy steels. Ultimate strength, s. Yield strength, Percent Condition ksi MPa ksi MPa elongation Material SAE no. 36 296 331 Annealed 57 393 43 1020 1020 1020 36 48 64 Hot rolled 65 448 Cold drawn 441 20 75 517 Annealed 75 517 51 352 30 1040 90 Hot Cold drawn 97 669 82 365 16 1040 641 WQT 700 WQT 900 WQT 1100 WQT 1300 876 1040 1040 814. 621 107 738 552 1040 87 600 434 1040 372 972 Annealed 614 54 1080 1080 1080 1080 141 1303 1234 OQT 700 OQT 900 OQT 100 OQT 1300 189 179 129 889 13 145 1000 103 710 17 117 807 70 483 23 1080 51 352 26 Annealed Cold drawn 1141 87 600 112 772 655 14 1141 172 1186 1331 1007 OQT 700 OQT 900 OQT 1100 OQT 1300 1141 193 889 669 146 1141 1141 116 800 20 1141 94 648 68 469 4140 Annealed 95 655 60 414 26 212 12 1462 1193 OQT 700 OQT 900 OQT 1100 OQT 1300 1593 231 187 4140 173 1289 1014 4140 4140 147 131 903 18 4140 118 814 696 276 17 724 1813 1351 1027 40 105 263 196 5160 Annealed OQT 700 OQT 900 OQT 1100 OQT 1300 5160 238 1641 5160 1234 12 132 103 910 710 5160 149 5160 115 793 23
Design Against Fluctuating Loads
Machine elements are subjected to varieties of loads, some components are subjected to static loads, while some machine components are subjected to fluctuating loads, whose load magnitude tends to fluctuate. The components of a machine, when rotating at a high speed, are subjected to a high degree of load, which fluctuates from a high value to a low value. For the machine elements under the action of static loads, static failure theories are applied to know the safe and hazardous working conditions and regions. However, most of the machine elements are subjected to variable or fluctuating stresses, due to the nature of load that fluctuates from high magnitude to low magnitude. Also, the nature of the loads is repetitive. For instance, shafts, bearings, cams and followers, and so on.
Design Against Fluctuating Load
Stress is defined as force per unit area. When there is localization of huge stresses in mechanical components, due to irregularities present in components and sudden changes in cross-section is known as stress concentration. For example, groves, keyways, screw threads, oil holes, splines etc. are irregularities.
![A structural support for a machine is subjected to a static compression load of 20 kN.
The support is manufactured from a circular rod made from SAE 1040 Hot Rolled steel.
Specify suitable diameter for the cross section of the rod based on the basic size. Steel
data are available in Table A-10 from the textbook.
A-10 Typical propertics of carbon and alloy steels.
Ultimate strengih, s.
Yield strength,
Percent
Material SAE no.
Condition
ksi
MPa:
ksi
MP
clongation
Anncaled
Hot rolled
Cold drawn
57
65
75
393
448
517
43
48
64
296
331
441
36
36
20
1020
1020
1020
1040
Annealed
75
$17
352
30
Hot
1010
565
641
621
s52
16
Cold drawn
WQT 700
WQT 900
WQT 1100
WQT 1300
1040
876
814.
19
22
127.
1040
1040
1040
1040
107
87
600
63
434
32
1080
1080
1080
1080
Annealed
OQT 700.
OQT 900
OQT 100
OQT 1300
89
189
179
145
117
614
1303
1234
1000
807
54
141
129
372
972
889
P10
13
17
103
70
483
1080
352
655
T186
中6
14
Annealed
Cold drawn
OQT 700
OQT 900
OOT 1100
OQT 1300
87
112
193
146
116
94
600
772
1331
1007
800
648
1141
95
1141
172
129
97
1141
889
669
469
15
20
1141
1141
68
1141
655
1593
1289
1014
814
414
1462
1193
903
696
26
95
231
187
147
118
50
Annealed
OQT 700
OQT 900
OQT 1100
OQT 1300
4140
212
173
131
12
15
4140
4140
18
23
4140
4140
276
1641
1234
910
710
17
Annealed
OQT 700
OQT 900
OOT 1100
OOT 1300
105
263
196
149
115
724
1813
1351
1027
793
40
238
179
5160
5160
12
5160
5160
5160
103
23
Ocher propertics are approximately the same for all carbon and alloy stecls:
Modulus of elasticity in tension 30 000 000 psi (207 GPa).
Modulus of elasticity in shear= 11 500 000 psi (80 GPa).
Density =0.283 lb /in (7680 kg/m.
POOT means oil quenched and tempered. WOT means water quenched and tempered.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F94307503-dae1-4282-8af7-1b6aa282d7d2%2F58d9b99a-dfe4-435b-b328-0f95d85c5630%2Fd2wrxir_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Step by step
Solved in 2 steps with 2 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Elements Of Electromagnetics](https://www.bartleby.com/isbn_cover_images/9780190698614/9780190698614_smallCoverImage.gif)
![Mechanics of Materials (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134319650/9780134319650_smallCoverImage.gif)
![Thermodynamics: An Engineering Approach](https://www.bartleby.com/isbn_cover_images/9781259822674/9781259822674_smallCoverImage.gif)
![Elements Of Electromagnetics](https://www.bartleby.com/isbn_cover_images/9780190698614/9780190698614_smallCoverImage.gif)
![Mechanics of Materials (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134319650/9780134319650_smallCoverImage.gif)
![Thermodynamics: An Engineering Approach](https://www.bartleby.com/isbn_cover_images/9781259822674/9781259822674_smallCoverImage.gif)
![Control Systems Engineering](https://www.bartleby.com/isbn_cover_images/9781118170519/9781118170519_smallCoverImage.gif)
![Mechanics of Materials (MindTap Course List)](https://www.bartleby.com/isbn_cover_images/9781337093347/9781337093347_smallCoverImage.gif)
![Engineering Mechanics: Statics](https://www.bartleby.com/isbn_cover_images/9781118807330/9781118807330_smallCoverImage.gif)