At what stress threshold does material elongation accelerate rapidly relative to load increments______________?
Show answer Hide answer
Answer: D. yielding point of the material
Explanation
The yielding point marks the specific stress threshold where plastic deformation initiates and material elongation accelerates rapidly under loads. At this critical juncture, atomic crystal planes slide past each other, causing massive strain increases with little or no added stress. This distinct mechanical behavior distinguishes the elastic working range from the permanent plastic deformation domain of structural metals. Yield strength is a vital engineering parameter used to establish safe maximum working stress limits for structural components. Plain carbon steels often exhibit a well-defined upper and lower yield point followed by a large plastic strain plateau. Metallurgical alloying and heat treatment processes can significantly raise the yield point to improve structural load-bearing capacity.
The elastic point represents the limit of reversible deformation, not the threshold where plastic elongation accelerates dramatically. Plastic point is not standard technical terminology for the specific stress threshold initiating rapid material yielding behavior. The breaking point occurs much later in the tensile test after extensive strain hardening and necking deformation have transpired.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What stress level is reached at the point of tensile fracture__________?
Show answer Hide answer
Answer: A. Breaking stress
Breaking stress is the nominal stress recorded at the exact moment of rupture or tensile fracture of the test specimen. This value represents the final force reading divided by the original cross-sectional area right whe...
Q2. What approximate percentage area reduction occurs in a cast iron test specimen during tension testing_________________?
Show answer Hide answer
Answer: E. negligible
Cast iron is a brittle material that exhibits negligible plastic deformation during tension testing. Graphite flakes in its microstructure act as internal stress concentrators, causing sudden brittle fracture. Because it...
Q3. How does the peak stress induced by a sudden load compare to a gradual load application________________?
Show answer Hide answer
Answer: C. two times
A suddenly applied load transfers kinetic energy that instantaneously doubles the maximum strain and stress. Gradual loading allows the material to deform slowly while internal resistance builds up alongside the load. Dy...
Q4. How does the ultimate tensile stress of mild steel compare to its ultimate compressive stress__________________?
Show answer Hide answer
Answer: B. more
Mild steel has a higher ultimate tensile strength compared to its ultimate compressive strength due to internal microstructural behavior under loads. Internal microstructural slip systems and dislocation movements behave...
Q5. What is the tensile stress value recorded at the exact moment of fracture in a material_________________?
Show answer Hide answer
Answer: A. breaking stress
Breaking stress is calculated at the exact moment when the material fractures completely. This value represents the final stress sustained before the structural member breaks apart entirely. Engineers measure this specif...
Q6. What physical condition is represented by a non-yielding support_________________?
Show answer Hide answer
Answer: D. slope of the beam at the support is zero
A non-yielding built-in or fixed support provides complete rigidity against both displacement and rotation. Because rotation of the structural member is entirely prevented at the fixed boundary, the slope must be zero. T...