Joint Design & Load Calculations Flashcards
7 cards from real CFS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Joint Design & Load Calculations flashcards as text
When specifying fastener thread engagement length in a tapped hole, the minimum engagement required to develop the full tensile strength of the bolt in steel is approximately:
Answer: 1.0 × nominal bolt diameter
For steel tapped holes, approximately 1.0× the bolt diameter of thread engagement is sufficient to develop the bolt's tensile strength before thread stripping occurs.
The 'load introduction factor' n in VDI 2230 bolt calculation accounts for:
Answer: Where along the grip length the external load enters the joint, affecting bolt load amplification
n (ranging 0 to 1) represents the fraction of the joint thickness through which the external force is introduced; it modifies how much of the external load the bolt actually sees.
A bolted joint connecting two steel plates is designed as 'slip-critical.' This classification means:
Answer: The connection must not slip into bearing under the service load (relies on friction)
Slip-critical (friction-type) connections rely on the clamping force and friction between faying surfaces to transfer shear without bolt-hole contact under service loads.
For a bolted joint in a pressure vessel, the ASME Boiler & Pressure Vessel Code requires the bolt area to satisfy two loading conditions. What are they?
Answer: Gasket seating condition (no pressure) and operating condition (with pressure)
ASME BPVC requires bolts to satisfy both the gasket seating condition (cold, atmospheric) and the operating condition (hot, pressurized), with the governing (larger) bolt area used.
The stress concentration factor Kt at the first engaged thread of a bolt in tension is significantly higher than in the shank because:
Answer: The abrupt change in cross-section and helix geometry creates a geometric stress riser
The thread root notch creates a geometric stress concentration, and the first engaged thread carries the highest portion of the bolt load, making it the most common fatigue initiation site.
In the analysis of a bolt circle (pattern on a circular flange), when the flange is subjected to an overturning moment, the bolt that carries the maximum tension is located:
Answer: Farthest from the neutral axis on the tension side
Similar to beam bending, bolts farthest from the neutral axis on the tension side carry the maximum tensile load due to the overturning moment.
Which of the following correctly describes the effect of increased surface roughness on the slip coefficient (μ) in a slip-critical bolted connection?
Answer: Rougher surfaces increase μ, increasing slip resistance
Increased surface roughness raises the friction coefficient μ between faying surfaces, directly increasing the slip resistance of the connection for a given bolt pretension.