Stress Analysis & Mechanical Integrity Flashcards
7 cards from real SPED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Stress Analysis & Mechanical Integrity flashcards as text
What is a 'two-anchor piping system,' and what is its significance in flexibility analysis?
Answer: A system fixed at two points, with all thermal growth absorbed by pipe flexibility between those anchors
In a two-anchor system, thermal expansion between fixed endpoints must be absorbed entirely by the pipe's elastic flexibility, making flexibility analysis critical.
Which condition triggers a 'fatigue evaluation' per ASME B31.3 Chapter IX (High Pressure Piping)?
Answer: Piping subject to cyclic conditions exceeding the design cycle count or severe cyclic service criteria
Chapter IX requires explicit fatigue analysis when piping experiences severe cyclic service, where the number or magnitude of stress cycles exceeds defined thresholds.
What is the function of a 'limit stop' (or displacement limiter) in a piping support system?
Answer: Allows free thermal movement within a gap but restrains the pipe during large displacements from seismic or slug flow
A limit stop allows normal thermal movement within a defined gap clearance but engages to restrain the pipe against large-displacement dynamic events like earthquakes.
In ASME B31.3, the stress range reduction factor (f) is applied when:
Answer: The number of full displacement cycles exceeds 7,000 over the design life
When the total design cycle count exceeds 7,000, the f factor reduces the allowable displacement stress range to account for cumulative fatigue damage.
Which of the following best describes 'shake-down' behavior in a piping system?
Answer: The system yields plastically in early cycles but reaches elastic behavior in subsequent cycles
Shakedown occurs when initial plastic straining during first few thermal cycles creates a residual stress state that allows all subsequent cycles to remain elastic.
During a hydrostatic pressure test of a piping system, which stress component is most critical to evaluate?
Answer: Hoop (circumferential) stress in the pipe wall due to test pressure
Hydrostatic test pressure is typically 1.5 times design pressure, making hoop stress the primary concern to ensure the pipe wall can sustain the elevated test condition.
What is the primary advantage of using a 3D piping stress model over a 2D simplified analysis?
Answer: 3D models capture out-of-plane loading, combined stress effects, and accurate support reactions across complex geometries
Three-dimensional models accurately account for out-of-plane moments, combined biaxial stresses, and realistic support configurations that 2D simplifications cannot capture.