Question

Fatigue failure is associated with:

a) Lack of fill
b) Notching
c) Base metal properties
d) Chemical properties of the weldment

Answer 1

Fatigue failure is often caused by repetitive stress and is highly influenced by notches, which act as stress concentrators leading to crack initiation and propagation.

Step-by-step explanation:

Fatigue failure in materials is often associated with repetitive stress cycles applied to a component over time which can ultimately lead to crack initiation and propagation resulting in failure. When considering the options provided:

• Lack of fill can lead to improper joint formation and potential areas of stress concentration, but it is more directly associated with welding defects rather than material fatigue.
• Notching or stress concentrators can significantly contribute to fatigue failure by providing areas where stress is amplified and cracks can easily initiate.
• Base metal properties are crucial in determining the likelihood of fatigue failure, as different materials will have varying resistance to repetitive loading.
• Chemical properties of the weldment can influence the fatigue life due to factors like corrosion; however, the mechanical properties and geometry typically have a larger immediate impact on fatigue.

Therefore, the answer is b) Notching, as notches are known to be stress concentrators that can lead to fatigue failure.