I work for the same problem recently, and I choose the Chapter 11 of Taiwanese LSD Code to solve the yield problem. I can calculate the limitation of the flange or web for the H beam, and the formulas are just to control its allowable reaction force. Of course, the reaction force may be too large for the H beam, but I can choose the larger H beam for the engineering construction design. The ASTM A572 Gr.50 H beam, RH900x300x16x28, is selected, and the formulas 11.2-1 & 11.2-2 are also selected for the present situations. If you wanna know how to define N, you can see the Figure C11.2-1 where is located on the Taiwanese LSD Code. Besides, the parameter k is NOT tf, but you have to include the circular region which is k = tf + R. In my engineering case, I don't have to add the stiffening plates, so that I just provide the fundamental formulas. The steel material is not JIS or CNS standard, so that I don't have to reduce the yield stress Fyf for the flange whose thickness is less than 1.5in. Hence, I can check whether the size of H beam is enough or not, so that the yield problem has been solved.



![=1.0\times \left [ 5\times \left ( 2.8+1.8 \right )+40 \right ]\times 3.52\times 1.6=354.816tf>R_{u}=82.392tf](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_sQdCdbYMOOs_nLBExsyaiY8Ge8mNSTEk5AN5UDmi8JATPLCU3_4gIvpDGXPi5sGgWm4xdhnqmye4YzEP1VnkwNNAnnhlw6BfOZ5Bc66C5qPhsXHidjORQyOEaBEtQcexu-02SIWCgf8L2fHng_h8Yxz295YZyJXKSLtmmVGfswwo89g5dJ74TADkD28S0_FIOUWscelkDmOkLCRj9yHYn-moNd1x1kfZwE2TH-YfxJhvrARYTKr85cr10UGxM0u7AfhCAhKmyFYbVpbE1LflaXKr0x=s0-d)
![\phi R_{n}=0.75\times 36t_{w}^{2}\left \{ 1+3\left [ \frac{N}{d} \right ]\left [ \frac{t_{w}}{t_{f}} \right ]^{1.5} \right \}\sqrt{\frac{F_{yw}t_{f}}{t_{w}}}](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vMpnE_lvDXqo-9E9ii3P4gJAPpXcKj_H_nSqJ86usQl6T8tn-pFaCwccIiL7fDCgYFwl0gKu8lwdYIFlcGj-WT5Ym4LPyiyfwweOd6qsrRkfjN7571RLI0jCE5R8y3mzyV1XtwumsqKW7A7_8hlDBcrNRcmCzBl_m7vn-AV-hdYGJCYosD35gyqkQS8pB3-rzXW67jbufkh6cMf5dr10qJKJ75XkEL4pvUgn3fTU7hgDzG7P4vOo5QjnB_kiyt2i_qGMh9rHIQNxqjIuyCst75YPpvh-12IZBeGoEu9ifIz5wPvuZsmC87daor2Iiwd2amQdIqw1H54akBoEYS5Ar536GGyFsc3YVxaB0F8y5o-TLqjdyGIODJv-6hhQI2EYX8y2SSjcKBHWnXVv1IBYMGUEIWbYM62Zi2Ye6sno_gm6HjMfdzjC3dpN7X7JXatwot=s0-d)
![=0.75\times 36\times 1.6^{2}\times \left [ 1+3\times \left ( \frac{40}{90} \right )\times \left ( \frac{1.6}{2.8} \right )^{1.5} \right ]\times \sqrt{\frac{3.52\times 2.8}{1.6}}](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vFSeWzx56jlAwaKBNa4rlkGrRvmEkSGqoJL5wug8IBy7IC930zUnpBEPkfoAuL--eUlDfjJf-3535UtRexcZVLapD7And41V-UkuYrk6SZ5LGMiOodAlBOgcmId3GJyLb8jgKvltavYy3ZgvVss9HkZ_m4OFZlO7ccgaBN_QX8bPmOYnro8DUh2OKkIJG6nWfAtWzacP3zFiqaONgO6FYW3OzTRnmawqUIpe5iBuKeoge6P_88MsDCTob8iXrTxzbbmZMEr3PeWYHPNnx6pPb3z18s7DtjPoOlUwfSd7i3cJoVKf5esXoYYCQZXPpfKjKCG1gxjzjFIL5cQV1kJcRMNQM654kfGklNLLEVbjTridSp8eBGaO8JJhwmErXwRyDtiQ6g4TKIBvUMZiDYW3fSWb_gZ9YI77TH4GehxoZqhPROLEAD1yE=s0-d)

Reference
Reference
- 內政部營建署(2010)鋼結構極限設計法規範及解說,內政部營建署。