Machine Design Flashcards
6 cards from real BME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Machine Design flashcards as text
In journal bearing design, the Sommerfeld number represents:
Answer: A dimensionless parameter relating speed, viscosity, load, and geometry
The Sommerfeld number is a dimensionless bearing parameter combining viscosity, speed, load, and bearing geometry used to predict performance.
Which type of welded joint is most efficient under tensile loading?
Answer: Butt joint
A butt joint aligns members end-to-end and, when fully penetrated, provides nearly the same strength as the base metal under tensile loads.
What does 'L10 life' represent for a rolling element bearing?
Answer: Life at which 90% of bearings will survive
L10 life is the number of revolutions (or hours) at which 90% of a group of identical bearings will still be operating without fatigue failure.
A power screw is primarily designed to:
Answer: Convert rotary motion to linear motion and transmit power
A power screw converts rotational input torque into translational output force, used in jacks, presses, and lead screws.
The interference fit between a shaft and a hub is designed to transmit load by:
Answer: Friction from radial pressure
An interference fit creates a radial compressive pressure at the interface, generating sufficient friction to transmit torque and axial loads.
Which failure theory is most appropriate for ductile materials under static loading?
Answer: Maximum shear stress (Tresca) theory
The Maximum Shear Stress (Tresca) theory is widely used for ductile materials and predicts yielding when the maximum shear stress reaches half the yield strength.