(a) Appropriate boundary condition at the bottom y = 0 .

Question

Spur gears Note : Exam is open notes &tables / Answer all questions. Q.1. The press shown for Figure.1 has a rated load of 22 kN. The twin screws have double start Acme threads, a diameter of 50 mm, and a pitch of 6 mm. Coefficients of friction are 0.05 for the threads and 0.08 for the collar bearings. Collar diameters are 90 mm. The gears have an efficiency of 95 percent and a speed ratio of 60:1. A slip clutch, on the motor shaft, prevents overloading. The full-load motor speed is 1720 rev/min. (a) When the motor is turned on, how fast will the press head move? (Vm= , Vser. = ) (5M) (b) What should be the horsepower rating of the motor? (TR=, Tc= Pser. = " Bronze bushings Foot Motor Bearings watt, Pm= watt, Pm= h.p.) (20M) 2['s Fig.1 Worm Collar bearing

Answer 1

Question

Chapter 4, Problem 4.43P

To determine

(a)

Appropriate boundary condition at the bottom y=0.

To determine

(b)

Appropriate boundary condition at the surface y=h.

Expert Solution & Answer

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Students have asked these similar questions

Spur gears Note : Exam is open notes &tables / Answer all questions. Q.1. The press shown for Figure.1 has a rated load of 22 kN. The twin screws have double start Acme threads, a diameter of 50 mm, and a pitch of 6 mm. Coefficients of friction are 0.05 for the threads and 0.08 for the collar bearings. Collar diameters are 90 mm. The gears have an efficiency of 95 percent and a speed ratio of 60:1. A slip clutch, on the motor shaft, prevents overloading. The full-load motor speed is 1720 rev/min. (a) When the motor is turned on, how fast will the press head move? (Vm= , Vser. = ) (5M) (b) What should be the horsepower rating of the motor? (TR=, Tc= Pser. = " Bronze bushings Foot Motor Bearings watt, Pm= watt, Pm= h.p.) (20M) 2['s Fig.1 Worm Collar bearing

Problem 2 (55 pts). We now consider the FEM solution of Problem 1.(a) [5pts] Briefly describe the 4 steps necessary to obtain the approximate solution of thatBVP using the Galerkin FEM. Use the minimum amount of math necessary to supportyour explanations.(b) [20pts] Derive the weak form of the BVP.(c) [10pts] Assuming a mesh of two equal elements and linear shape functions, sketch byhand how you expect the FEM solution to look like. Also sketch the analytical solutionfor comparison. In your sketch, identify the nodal degrees of freedom that the FEMsolution seeks to find.(d) [10pts] By analogy with the elastic rod problem and heat conduction problem considered in class, write down the stiffness matrix and force vector for each of the twoelements considered in (c).(e) [10pts] Assemble the global system of equations, and verbally explain how to solve it.

An aluminum rod of length L = 1m has mass density ρ = 2700 kgm3 andYoung’s modulus E = 70GPa. The rod is fixed at both ends. The exactnatural eigenfrequencies of the rod are ωexactn =πnLqEρfor n=1,2,3,. . . .1. What is the minimum number of linear elements necessary todetermine the fundamental frequency ω1 of the system? Discretizethe rod in that many elements of equal length, assemble the globalsystem of equations KU = ω2MU, and find the fundamentalfrequency ω1. Compute the relative error e1 = (ω1 − ωexact1)/ωexact1.Sketch the fundamental mode of vibration.