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Compute the normal stress

Consider the I-beam cross-section:

The table below has the geometric properties for different specifications for a steel beam:

Designation	h (in)	w (in)	Ix (in^4)	Iy (in^4)
S12 x 50	12	5.477	305	15.7
S12 x 40.8	12	5.252	272	13.6
S12 x 35	12	5.078	229	9.87
S12 x 31.8	12	5	218	9.36
S10 x 35	10	4.944	147	8.36
S10 x 25.4	10	4.661	124	6.79
S8 x 23	8	4.171	64.09	4.31
S8 x 18.4	8	4.001	57.6	3.73
S7 x 20	7	3.86	42.4	3.17
S7 x 15.3	7	3.662	36.7	2.64

For the beam designations indicated below, determine the maximum normal stress $\sigma_x$ assuming that the maximum moment is equal to $M_{max} = 6 \times 10^5 \rm\ lb \cdot in$.

Designation	$\sigma_x$
S12 x 40.8
S8 x 18.4
S10 x 35
S7 x 15.3

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Correct answer

Designation	$\sigma_x$
S12 x 40.8	`13.2352941176`
S8 x 18.4	`41.6666666667`
S10 x 35	`20.4081632653`
S7 x 15.3	`57.2207084469`

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Question

QID:

demo/annotated/engBeamStress

Title:

Compute the normal stress

Variant

Started at:

2026-09-19 10:06:33 (CDT)

Duration:

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{
  "sigma1": 13.23529411764706,
  "sigma2": 41.666666666666664,
  "sigma3": 20.408163265306122,
  "sigma4": 57.220708446866475
}

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