Engineering Answers

The welded cantilever is subjected to a cyclic torsional load of Tmax = 2 kN-m and Tmin = 1 kN-m. The material is AISI 1018 CD. Calculate: Fatigue safety factor according to Gerber criterion. Consider 90% reliability and stress concentration at end of parallel fillet weld.

A thick walled cylinder is subjected to a fluctuating internal pressure of 0 to 100 MPa. The outer and inner diameters of the cylinder are 250 mm and 150 mm, respectively. The material is Ferritic-pearlitic steel with Sut = 800 MPa and Sy = 600 MPa. The fracture toughness of the material is 50 MPa√m. The ultrasonic detector detects a nick of 0.2 mm (as shown in the following figure). Estimate the No. of cycles life remaining of this cylinder.

A machine part is loaded as shown in the following figure. The moment, M varies from -10 kN-m to +20 kN-m and the force, F varies from 0 to 10 kN. The material is AISI 1040 annealed steel. Consider, machined surface, 100° Celsius temperature operation, 95% reliability. Determine the minimum factor of safety for this part based on Soderberg equation. Given that, d = 50 mm and thickness of the part t = 20 mm.

3.2.1 Write the state-space form of equation using the state assignments

X = [Vx iL]^t , y = Vx.

3.2.2 Write the state-space form of equation (7) using the state assignments

X = [Vx V×]^t , y = Vx

3.2.3 Show that the transfer function of the circuit in Figure 4, could be written :

G2(s) = Vx/Vu = 1/ (LCs² + CRs +1)

3.2.4 Show that the transfer function G2(s) could also be written as :

G3(s) = w²n/(s² + 2 ζwns + w²n) where the natural frequency is given as wn = 1/√LC .

What is the expression for the damping factor ζ.

•Derive the transfer function G1(s) = X(s)/U(s) for the first-order system given by the dynamic equation: dx/dt + kx = u(t).

•Obtain and sketch the impulse response for the given first-order system, when

(i) k >0

(ii) k=0

(iii) k<0

Calculate the capacity of a fuel tank and the fuel pump capacity of a Diesel power plant with

5500 kw installed capacity and 50% plant capacity factor. You have to procure fuel monthly with

150% contingency.

A Dodecane fuel will be used in an IC Engine. The Air-Fuel ratio is 30:1. Calculate the percent

excess air.

5. Two shafts 30 in. apart, each carrying a four-step pulley, are to be connected by a cross belt. The driving shaft is to turn 180 rpm while the driven shaft is to turn 50, 150, 250, and 600 rpm. The smallest step of the driver is 10 in. in diameter. Find (a) the diameters of all the steps, (b) angle of contact for each pair of pulleys, and (c) belt length.

4. A pulley 600 mm. in diameter transmits 40 kW at 500 rpm. The arc of contact between the belt and pulley is 144° having a center distance of 1100 mm. Determine: (a) diameter of the driven pulley for open belt drive, (b) speed of the driven pulley, and (c) belt length for open belt connection.

Now, what if, instead, you sold the house for less than you paid for it—say, for $187,500? The same equation can be used to calculate your loss, or the negative rate of return, on the transaction.