I am refering to the book - Mechanics of Materials by Beer, Johnston and DeWolf (McGraw-Hill) topic 8.2.

When we design a wide-flange beam, we must consider two conditions. First, the shear stress at the maximum shear section must not exceed the allowable shear stress. Second, the principal stress at the junction of the web and the flange at the section of the maximum moment must also be compared to the allowable normal stress. This is straightforward and clear to me.

My question is, in some cases, I found that the maximum shear stress at the junction of the web and the flange of the maximum moment is greater than that at the centroid of the section calculated from the maximum shear section. Do we need to compare that shear stress to the allowable instead? I don't find any examples in the book that consider the shear stress I just mentioned. So, I'm thinking there might be a reason for that.

Thank you very much in advance for your comments :).

-june