Shigley's Mechanical Engineering Design (McGraw-Hill Series in Mechanical Engineering)
10th Edition
ISBN: 9780073398204
Author: Richard G Budynas, Keith J Nisbett
Publisher: McGraw-Hill Education
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Chapter 6, Problem 28P
The figure shows a formed round-wire cantilever spring subjected to a varying force. The hardness tests made on 50 springs gave a minimum hardness of 400 Brinell. It is apparent from the mounting details that there is no stress concentration. A visual inspection of the springs indicates that the surface finish corresponds closely to a hot-rolled finish. Ignore curvature effects on the bending stress. What number of applications is likely to cause failure? Solve using:
- (a) Modified Goodman criterion.
- (b) Gerber criterion.
Problem 6-28
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6-28 The figure shows a formed round-wire cantilever spring subjected to a varying force.
The hardness tests made on 50 springs gave a minimum hardness of 400 Brinell. It is
apparent from the mounting details that there is no stress concentration. A visual
inspection of the springs indicates that the surface finish corresponds closely to a hot-
rolled finish. Ignore curvature effects on the bending stress. What number of applica-
tions is likely to cause failure? Solve using:
(a) Goodman criterion.
(b) Gerber criterion.
= 40 lbf
max
12 in-
= 20 lbf
min
Problem 6-28
Starting with a spring index of C = 10, design a compression coil spring of 302 stainless wire with squared ends. The spring deflects 50 mm when a force of 90 N is applied and closes to solid when ys is 60 mm. At closure, use a design factor of 1.2 guarding against yielding. Select the smallest diameter wire where wire diameters are available in 0.2-mm increments between 0.2 and 3.2 mm. For the design, specify the wire diameter, the inside and outside diameters of the coil, the spring rate, the total number of coils, the free length of the spring, the final factor of safety, and stability conditions.
A mechanism used in a punchingmachinery consists of a tension spring assembled with a preload of 30 N. The wire diameter of spring is 2 mm with a spring index of 7. The spring has 10active coils. The spring wire is hard drawn and oil tempered having the following material properties:Design shear stress = 780 MPa Modulus of rigidity = 80 kN/mm2Identify (a) the initial torsional shear stress in the wire, (b) the spring rate, and (c) the force to cause the body of the spring to reach its yield strength.
Chapter 6 Solutions
Shigley's Mechanical Engineering Design (McGraw-Hill Series in Mechanical Engineering)
Ch. 6 - A 10-mm steel drill rod was heat-treated and...Ch. 6 - Prob. 2PCh. 6 - A steel rotating-beam test specimen has an...Ch. 6 - A steel rotating-beam test specimen has an...Ch. 6 - A steel rotating-beam test specimen has an...Ch. 6 - Repeat Prob. 6-5 with the specimen having an...Ch. 6 - A steel rotating-beam test specimen has an...Ch. 6 - Derive Eq. (6-17). Rearrange the equation to solve...Ch. 6 - For the interval 103 N 106 cycles, develop an...Ch. 6 - Estimate the endurance strength of a...
Ch. 6 - Two steels are being considered for manufacture of...Ch. 6 - A 1-in-diamctcr solid round bar has a groove...Ch. 6 - A solid square rod is cantilevered at one end. The...Ch. 6 - A rectangular bar is cut from an AISI 1020...Ch. 6 - A solid round bar with diameter of 2 in has a...Ch. 6 - The rotating shaft shown in the figure is machined...Ch. 6 - The shaft shown in the figure is machined from...Ch. 6 - Solve Prob. 6-17 except with forces F1 = 1200 lbf...Ch. 6 - Bearing reactions R1 and R2 are exerted on the...Ch. 6 - A bar of steel has the minimum properties Se = 40...Ch. 6 - Repeat Prob. 6-20 but with a steady torsional...Ch. 6 - Repeat Prob. 6-20 but with a steady torsional...Ch. 6 - Repeat Prob. 6-20 but with an alternating...Ch. 6 - A bar of steel has the minimum properties Se = 40...Ch. 6 - The cold-drawn AISI KUO steel bar shown in the...Ch. 6 - Repeat Prob. 6-25 for a load that fluctuates from...Ch. 6 - An M14 2 hex-head bolt with a nut is used to...Ch. 6 - The figure shows a formed round-wire cantilever...Ch. 6 - The figure is a drawing of a 4- by 20-mm latching...Ch. 6 - The figure shows the free-body diagram of a...Ch. 6 - Solve Prob. 6-30 except let w1 = 2.5 in. w2 = l.5...Ch. 6 - For the part in Prob. 630, recommend a fillet...Ch. 6 - Prob. 33PCh. 6 - Prob. 34PCh. 6 - A part is loaded with a combination of bending,...Ch. 6 - Repeat the requirements of Prob. 6-35 with the...Ch. 6 - 6-37 to 6-46For the problem specified in the build...Ch. 6 - 6-37 to 6-46For the problem specified in the build...Ch. 6 - 637 to 646 For the problem specified in the table,...Ch. 6 - For the problem specified in the table, build upon...Ch. 6 - 6-37 to 6-46 For the problem specified in the...Ch. 6 - 6-37 to 6-46 For the problem specified in the...Ch. 6 - 6-37 to 6-46 For the problem specified in the...Ch. 6 - Problem Number Original Problem, Page Number 637...Ch. 6 - 6-37 to 6-46 For the problem specified in the...Ch. 6 - 6-37 to 6-46 For the problem specified in the...Ch. 6 - 6-47 to 6-50 For the problem specified in the...Ch. 6 - 6-47 to 6-50 For the problem specified in the...Ch. 6 - Prob. 49PCh. 6 - Prob. 50PCh. 6 - 6-51 to 6-53 For the problem specified in the...Ch. 6 - 6-51 to 6-53 For the problem specified in the...Ch. 6 - 6-51 to 6-53 For the problem specified in the...Ch. 6 - Solve Prob. 6-17 except include a steady torque of...Ch. 6 - Solve Prob. 618 except include a steady torque of...Ch. 6 - In the figure shown, shaft A, made of AISI 1020...Ch. 6 - A schematic of a clutch-testing machine is shown....Ch. 6 - For the clutch of Prob. 657, the external load P...Ch. 6 - A flat leaf spring has fluctuating stress of max =...Ch. 6 - A rotating-beam specimen with an endurance limit...Ch. 6 - A machine part will be cycled at 350 MPa for 5...Ch. 6 - The material properties of a machine part are Sut...Ch. 6 - Repeat Prob. 662 using the Goodman criterion....
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