How is the effective area of a fillet weld determined?

How is the effective area of a fillet weld determined?

• A. Effective weld length X Effective throat
• B. Weld length X Weld throat angle
• C. Area equals thickness times length
• D. Length plus throat

Answer: (A)

The effective area of a fillet weld is the cross‑section that actually carries the load, and it is found by multiplying two geometric factors: the effective weld length along the joint and the effective throat (the shortest distance through the weld cross‑section measured perpendicular to the weld axis). So, A_eff = L_eff × a_eff. This reflects how the weld runs along the joint (length) and how thick the weld is where it does the work (the throat), giving a true cross‑sectional area that resists shear or tension. The other options don’t describe the cross‑section that carries load. The throat angle isn’t used to compute area, so multiplying by an angle doesn’t yield an area. Using plate thickness times length would mix the base material dimensions with the weld geometry and isn’t correct for the weld’s load‑carrying cross‑section. Adding length and throat gives a linear dimension, not an area.

The effective area of a fillet weld is the cross‑section that actually carries the load, and it is found by multiplying two geometric factors: the effective weld length along the joint and the effective throat (the shortest distance through the weld cross‑section measured perpendicular to the weld axis). So, A_eff = L_eff × a_eff. This reflects how the weld runs along the joint (length) and how thick the weld is where it does the work (the throat), giving a true cross‑sectional area that resists shear or tension.

The other options don’t describe the cross‑section that carries load. The throat angle isn’t used to compute area, so multiplying by an angle doesn’t yield an area. Using plate thickness times length would mix the base material dimensions with the weld geometry and isn’t correct for the weld’s load‑carrying cross‑section. Adding length and throat gives a linear dimension, not an area.