Author Topic: 8/17/2015 Basic Engineering Knowledge  (Read 1099 times)

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8/17/2015 Basic Engineering Knowledge
« on: August 27, 2015, 07:30:45 AM »
Question:

The piston of a hydraulic actuator is 1.5 inches in diameter and is subject to a hydraulic line pressure of 1500 psi.  Calculate what the cross sectional area should be (in2) if the design stress for the piston is 20,000 psi:

(A) .132 in2
(B) .232 in2
(C) .332 in2
(D) .432 in2

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Re: 8/17/2015 Basic Engineering Knowledge
« Reply #1 on: August 31, 2015, 01:40:48 PM »
The Answer is (A).

A basic principle is:

Pressure = Force / Area

Therefore:

1500 psi = Force / [π (1.5)2/4]   (the area of a circle = πd2/4)

1500 psi (1.76 in2) = Force

Force = 2640 lb (This force is acting on the piston)

Therefore:

Pressure = Force / Area
20,000 psi = 2640 lb / Area
Area = 2640 lb / 20,000 psi

Area = .132 in2