Calculate Shear Stress & Force in Beam for V=125kN

[joemama69]

Homework Statement

Determine the Max, Min & average shear stress, and the shear force in web

V = 125kN

Note th attachment

Homework Equations

The Attempt at a Solution

First I calculated the Moment of Inertia

I = (1/12)(bh³ - bh₁³ + th₁³) = 3.43X10^-4 m⁴

Max Shear Stress = (Vb/8It)(bh² - bh₁² + th₁²) = 28.4MPa

Min Shear Stress = (V/8It)(h² - h₁²) = 21.9MPa

Avg Shear Stress = (V/th₁) = 27.4MPa

V_web = (th₁/3)(2\tau_max + \tau_min) = 119.6 kN

Did I use all the correct equation. The example uses these equations but says they are in the web.

 

[PhanthomJay]

I guess if you are just using some given formulas ( corrected for typo errorrs) for max, min, avg shear stresses in a web and plugging in numbers, then there's not much I can say. Far better to understand the shear stress formula using the first moment of area Q. Otherwise it's just plug and chug.