1. Determine reasonable design values for the number of active coils, the wire and coil diameters...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
1. Determine reasonable design values for the number of active coils, the wire and coil diameters of an infinite-life helical compression spring with a minimum load of 12 lb force and a maximum load of 25 lb force, with an accompanying compression of 0.2 in. between them. The spring is for a food-service (kitchen) equipment and is ASTM A313 (302 stainless steel) so that the maximum stress is 0.455, since presetting is not required. The outside diameter of the coil cannot exceed 0.5 in. and the free length cannot exceed 2 in. Include a 10% clash allowance. Use shear modulus G = 11.5 x 106 psi. Use C = 5 to start your iteration. Buckling prevention criterion is ignored. (a) (3 marks) List the governing equations with their dependence on C intact for the iteration to arrive at the recommended design values. How many governing equations are there? (b) (2 marks) What is the main reason for the iteration need? (c) (3 marks) Obtain the first-iteration design values using the equation that does not depend on C nor N (but you still use C = 5 to start your iteration). Hint: Such equation can be obtained by converting the inequality that does not depend on C nor N into an equation. (d) (2 marks) Is there a need for second iteration? If yes, obtain the second-iteration design values. If no, state the first-iteration design values. Table 10-4 Constants & and m of S = Ald" for Estimating Minimum Tensile Strength of Common Spring Wires Material Music wire OQ&T wire Hard-drawn wire Chrome-vanadium wirel Chrome silicon wire!! 302 Stainless wire Phosphor-bronze wire" ASTM No. Exponent m A228 A229 A227 A232 A401 A313 BI59 0.145 0.187 0 0.190 0.168 0.108 0.146 0.263 0.478 0.028 0.064 Surface is smooth, free of defects, and has a bright, lustrous finish Has a slight heat-treating scale which must be removed before plating Surface is smooth and bright with no visible marks Aircraft-quality tempered wire, can also be obtained annealed Tempered to Rockwell C49, but may be obtained untempered Type 302 stainless steel "Temper CASIO Source Data from Design Handbook, 1987, p. 19. Diameter, in 4. kpsi - in 0.004-0.256 0.020-0.500 0.028-0.500 0.032-0.437 0.063-0.375 0.013-0.10 0.10-0.20 0.20-0.40 0.004-0.022 0.022-0.075 0.075-0.30 201 147 140 169 202 169 128 90 145 121 110 A, Diameter, mm MPa - mm" 0.10-6.5 0.5-12.7 0.7-12.7 0.8-11.1 1.6-9.5 0.3-2.5 2.5-5 5-10 0.1-0.6 0.6-2 2-7.5 2211 1855 1783 2005 1974 1867 2065 2911 1000 913 932 Relative Cost of Wire 2.6 1.3 1.0 3.1 4.0 7.6-11 8.0 1. Determine reasonable design values for the number of active coils, the wire and coil diameters of an infinite-life helical compression spring with a minimum load of 12 lb force and a maximum load of 25 lb force, with an accompanying compression of 0.2 in. between them. The spring is for a food-service (kitchen) equipment and is ASTM A313 (302 stainless steel) so that the maximum stress is 0.455, since presetting is not required. The outside diameter of the coil cannot exceed 0.5 in. and the free length cannot exceed 2 in. Include a 10% clash allowance. Use shear modulus G = 11.5 x 106 psi. Use C = 5 to start your iteration. Buckling prevention criterion is ignored. (a) (3 marks) List the governing equations with their dependence on C intact for the iteration to arrive at the recommended design values. How many governing equations are there? (b) (2 marks) What is the main reason for the iteration need? (c) (3 marks) Obtain the first-iteration design values using the equation that does not depend on C nor N (but you still use C = 5 to start your iteration). Hint: Such equation can be obtained by converting the inequality that does not depend on C nor N into an equation. (d) (2 marks) Is there a need for second iteration? If yes, obtain the second-iteration design values. If no, state the first-iteration design values. Table 10-4 Constants & and m of S = Ald" for Estimating Minimum Tensile Strength of Common Spring Wires Material Music wire OQ&T wire Hard-drawn wire Chrome-vanadium wirel Chrome silicon wire!! 302 Stainless wire Phosphor-bronze wire" ASTM No. Exponent m A228 A229 A227 A232 A401 A313 BI59 0.145 0.187 0 0.190 0.168 0.108 0.146 0.263 0.478 0.028 0.064 Surface is smooth, free of defects, and has a bright, lustrous finish Has a slight heat-treating scale which must be removed before plating Surface is smooth and bright with no visible marks Aircraft-quality tempered wire, can also be obtained annealed Tempered to Rockwell C49, but may be obtained untempered Type 302 stainless steel "Temper CASIO Source Data from Design Handbook, 1987, p. 19. Diameter, in 4. kpsi - in 0.004-0.256 0.020-0.500 0.028-0.500 0.032-0.437 0.063-0.375 0.013-0.10 0.10-0.20 0.20-0.40 0.004-0.022 0.022-0.075 0.075-0.30 201 147 140 169 202 169 128 90 145 121 110 A, Diameter, mm MPa - mm" 0.10-6.5 0.5-12.7 0.7-12.7 0.8-11.1 1.6-9.5 0.3-2.5 2.5-5 5-10 0.1-0.6 0.6-2 2-7.5 2211 1855 1783 2005 1974 1867 2065 2911 1000 913 932 Relative Cost of Wire 2.6 1.3 1.0 3.1 4.0 7.6-11 8.0
Expert Answer:
Related Book For
Shigleys Mechanical Engineering Design
ISBN: 9780073398211
11th Edition
Authors: Richard G. Budynas, J. Keith Nisbett
Posted Date:
Students also viewed these mechanical engineering questions
-
In a Hopfield neural network configured as an associative memory, with all of its weights trained and fixed, what three possible behaviours may occur over time in configuration space as the net...
-
s sf Define the terms opaque type and concrete type. [5 marks] The following is a shortened version of one of the definition modules described in the Modula-2 user manual: Provide a suitable...
-
Determine whether the given functions are even, odd, or neither. a. x sin(x) c. x cos(x) e. x sin(x) + x sin(x) f. x sin(x) + x cos(x) even h. x sin(x) + x cos(x) j. x cos (x) + x cos(x) b. x sin(x)...
-
What is the value of the test statistic when the within-groups variation is equal to 0? Explain.
-
The scatterplot shows the relationship between height (in inches) and weight (in pounds) for the members of the United States 2016 Olympic Track and Field team. Describe the relationship between...
-
When you walk through still air at a rate of \(1 \mathrm{~m} / \mathrm{s}\), would you expect the character of the airflow around you to be most like that depicted in Fig. 9.6a, b, or c? Explain....
-
Madison Seniors Care Center is a nonprofit organization that provides a variety of health services to the elderly. The center is organized into a number of departments, one of which is the...
-
Write a C function to set a bit in the binary representation of an unsigned integer number of four bytes (bits counting from right to left as bit0, bitl, bit2, ..., bit31), and display both the...
-
Explain how the achievement of new knowledge or skills related to this Program Outcome can translate to better decision-making as you progress in your career ?
-
1 Which of the following statements must be true of the circuit above? A. The voltage across each capacitor is the same. B. The charge on each capacitor must be the same. C. The voltage across C3...
-
1. GIVEN: Qd = 111 - 3P and Qs =-11 + 5P and Prices 0 to 20 intervals of 2, create a combined D & S schedule using the format below PRICE Qd Qs
-
A candy bar has an energy content of 200 Dietary Calories. What is approximate the available energy in joules? O 4 MJ O 100 kJ O 800kJ O 200 kJ
-
Tomlinson Company has the following production data for May: Beginning work in process, O units Units started, 62,000 Ending work in process, 5,000 units that are 100% complete for materials and 60%...
-
A. Stock mutual funds. Use the most recent statutory prospectus (or prospectus) found online at the mutual fund company's website for the following mutual funds to complete questions 1-4. It is...
-
Find the status of the CF, PF, AF, ZF and SF after the execution of the following instructions? MOV DI, 045AH MOV DX, 2FE7H MOV [DI], DX ADD [DI), DX O a. 1, 0, 1, 1, 0. O b. 0, 1, 0, 1, 1. O c. 0,...
-
Why can wastewater treatment requirements in Hawaii be less stringent than those in most locations on the U.S. mainland?
-
The shaft shown in Problem 724 is proposed for the application defined in Problem 3-83. Specify a square key for gear B, using a factor of safety of 1.1. Data in Problem 724 The shaft shown in the...
-
In the figure for Problem 13-35, pinion 2 is to be a right-hand helical gear having a helix angle of 30, a normal pressure angle of 20, 16 teeth, and a normal diametral pitch of 6 teeth/in. A motor...
-
The part shown is loaded at point C with 300 N in the positive x direction and at point E with 200 N in the positive y direction. The diameter of the bar ABD is 12 mm. Evaluate the likelihood of...
-
While the BohrSommerfeld condition sometimes gets the energy eigenvalues exactly correct, it can also be used for systems where the exact solution is not known. In this example, we will estimate the...
-
It's useful to see how our quantum perturbation theory works in a case that we can solve exactly. Let's consider a two-state system in which the Hamiltonian is...
-
Let's see how the variational method works in another application. Let's assume we didn't know the ground-state energy of the quantum harmonic oscillator and use the variational method to determine...
Study smarter with the SolutionInn App